AN-18应用指南

AP03407008E For more information visit:IEC contactors are increasinglybecoming the contactor of choice for power and motor control across the world. Contactors designed to IEC specifications provide a good balance of performance, size, accessories and low cost. However, there are several different governing standards, such as UL ® , NEC ® , CSA ® , IEC and others, that dictate how IEC contactors should be applied in a panel. In order to apply correctly, it is important to understand the performance requirements for these various standards.This application note discusses contactor application based on two common governing standardssystems, UL/CSA/NEC and IEC. This application note is merely a guide and is not intended to replace or serve as a substitute for UL/CSA/NEC and IEC standards. Always consult the actual standards or local standardsrepresentatives to ensure correct interpretation and compliance.New Information December 2007UL, CSA, NEC and CECUL (Underwriters Laboratories) is an organization that develops standards and test procedures and certifies products with a significant focus on product safety. UL Standard 508 covers the contactor design and test requirements and UL Standard 508A covers requirements for the design of a control panel. UL also is a Nationally Recognized Test Lab (NRTL) under OSHA, and products certified by UL are accepted by almost all jurisdictions in the US. OSHA Safety Standards, which are US law, containrequirements for “approval” (i.e., testing and certification) of electrical equipment by an NRTL.CSA (Canadian Standards Association) is a similar body in Canada. Contactors are certified to CSA C22.2 No.14. Installations in Canada are covered under the (CEC) Canadian Electrical Code, CSA C22.1. CSA is also an NRTL under OSHA.The NEC (National Electrical Code, also known as NFPA 70) is a specification that establishes minimum standards for the safe installation of electrical wiring and equipment in the US. The NEC was created and is maintained by the National Fire Protection Association (NFPA). The NEC is frequently mandated by states and localjurisdictions, and it is possible for different jurisdictions to adopt different revisions of NEC code.For more information visit: AP03407008EApplication NotePage 2Effective: December 2007Use of IEC Contactors in UL, CSA and NEC Regulated ApplicationsWhile there is some overlap in the NEC and UL standards, and the CEC and CSA standards, these specifications generally work together in concert to provide guidelines for safe design, application, and installation ofelectrical components and equipment, and often reference their counterpart's standards in their documentation. Even though IEC contactors are designed and tested to the IEC standard, they must also be tested according to UL standards if they are to be used as a UL approved device. For motor applications, conformance to UL Standard 508 and/or CSA C22.2 No.14 verifies that contactors are designed to handle most common standard motor applications.Contactors that meet UL requirements are assigned various ratings based on tests, including motor horsepower ratings and a general purpose ampere rating, among others (see example rating label in Figure 1 and Table 1 ).On the XT contactor label, the UL information is found on the bottom half of the label. These ratings are used in the selection and application of the contactor.According to the NEC, UL508A and CEC, the horsepower rating is used to size a contactor for a standard motor application. Although IEC contactors have ratings based on the IECstandard (such as the AC-3 current rating), these ratings are notrecognized or considered when sizing according to UL508A, CEC or NEC applications. See example below:Example10 hp Type B motor with the following nameplate ratings for use in a standard duty application under UL508A and/or CEC and/or NEC:■Rated Horsepower: 10 hp ■ Rated Voltage: 460V 60 Hz ■ Full Load Amperage: 14.0AAccording to Table 1 , The XTCE012B or the XTCE015B is appropriate for this application. The AC-3 rating cannot be considered when sizing this contactor for motors to UL/NEC/CEC because it is not a UL/CSA rating.If motors are used in severe duty applications, such as plugging orjogging, contactors should be derated based on UL/NEC/CEC guidelines. For non-motor loads, the general purpose ampere rating is used to size the contactor.The XT contactor was designed and tested to achieve the optimum ULhorsepower rating. As a result, it often has a higher horsepower rating than competitive lines based on physical size, and thus is often smaller than competitive lines for the same horse-power rating. By using the XTcontactor line, it is possible to design smaller, less expensive panels.Figure 1. Rating Label for XTCE012B Contactor Table 1. B Frame XT Contactor RatingsIEC RatingsUL/CSA RatingsAuxiliary ContactsCatalog Number —Screw TerminalsI e (A)I e = I th (A)Maximum kW Ratings AC-3Maximum 3-Phase Motor Rating, UL/CSA AC-3AC-1(60°C)3-Phase Motors 50 – 60 Hz 1-Phase hp Ratings 3-Phase hp Ratings 230/230V 380/400V 415V600/690V 115V200V230V200V230V460V575VFrame B779920202020 2.22.22.52.53344445.55.5 3.53.54.54.5 3/4 3/4 1/2 1/23/4 3/411111-1/21-1/21-1/21-1/23322333355557-1/27-1/21NO 1NC 1NO 1NC XTCE007B10_XTCE007B01_XTCE009B10_XTCE009B01_ 121216.515.5202020203.53.5445.55.57.57.577886.56.5771111222222333355335510101010101010101NO 1NC 1NO 1NCXTCE012B10_XTCE012B01_XTCE015B10_XTCE015B01_AP03407008E For more information visit: Application NoteEffective: December 2007Page 3Use of IEC Contactors in UL, CSA and NEC Regulated ApplicationsIEC StandardIEC (International ElectrotechnicalCommission) is an organization based in Europe that establishes standards for the design and application ofelectrical components and equipment. IEC standards have been adopted by countries in Europe (known asEuropean Norms or EN) and globally. It has become a common platform for the design of contactors across the world. Contactors tested to EN standards bear a CE mark.IEC Contactors are designed and tested according to standard IEC/EN60947-4-1. This standard is designed around very specificapplications (see example utilization categories in Table 3 ) and requires more sophisticated methods of device selection compared to UL, NEC and CEC. More ratings are provided in IEC based specifications as compared to UL/CSA. IEC ratings for the XT are located in the top portion of thecontactor ratings label and in technical specification documentation. Because the contactor performance is specified based on additional applications, IEC test requirements may not be as severe as UL or CSA testing, and in many cases, a smaller contactor can be used in an IEC application than can be used for the same application in UL.Selection of contactors based on the IEC standard begins with selecting the desired design life of the contactor. An electrical life between 1.2 to 1.5 million operations is a common choice. A higher electrical life may be chosen if the application requires a highoperation frequency or if the contactor is desired to perform for a longerperiod of time. The following example shows how electrical life could be determined:Example■Motor operates every 1 minute for 8 hours per day, 300 days per year. ■ The desired life is 10 years.1 operation/minute x 60 minutes/hour x 8 hours/day x 300 days/year x 10 years = approx 1.4M OperationsOnce the number of operations isknown, the contactor is selected based on the application, the full load current, and number of operations. The contactor ratings (see example in T able 2 ), as well as electrical life curves (see example in Figure 2 ) are used to size the contactor. See the example in the next column.Example■Contactor is to start a squirrel cage motor and switch off while running. ■ Motor nameplate is as follows: ❑ Power: 4 kW❑ Voltage: 400V 50 Hz ❑ Full Load Current: 8.8A■ Number of desired operations is 1.4M.Based on the application, the utilization category is AC-3. From Table 2 , the XTCE009B contactor is rated for 4 kW, 9A at 400V, which is appropriate based on the motor ratings. Figure 2 shows that theXTCE009B will perform at around 1.4M operations at 8.8 amps, so thiscontactor is sized appropriately based on the application and desired contactor life.In this example, if the desired life were 2M operations, a larger contactor size would have to be used. Using the data in Figure 2, the XTCE015B would be an appropriate contactor for nearly 2M operations based on 8.8 amp usage.For more information visit: AP03407008EApplication NotePage 4Effective: December 2007Use of IEC Contactors in UL, CSA and NEC Regulated ApplicationsFigure 2. Electrical Life Curves for B – G Frame XT Contactors at 400V AC-3Table 2. AC-3 Ratings for B & C Frame XT ContactorsᕃAt maximum permissible ambient temperature.DescriptionXTCE007B XTCE009BXTCE012B,XTCF020BXTCE015B XTCE018C XTCE025C XTCE032CRated Operational Current, 50/60 Hz ᕃ(I e ) in amperes 220/230V 240V 380/400V 415V 440V 500V 660/690V 1000V7777754— 9999975— 1212121212107— 15.515.515.515.515.512.59— 18181818181812— 25252525252515— 32323232323218— Rated power (P) in kilowatts 220/230V 240V 380/400V 415V 440V 500V 660/690V 1000V2.22.2344.53.53.5—2.5345.55.54.54.5—3.545.577.576.5—44.67.588.47.57—55.57.51010.51211—7.58.51114.515.517.514—10111519202317—AP03407008E For more information visit: Application NoteEffective: December 2007Page 5Use of IEC Contactors in UL, CSA and NEC Regulated ApplicationsTable 3. Examples of Utilization Categories for Low-Voltage Switchgear and Controlgear ᕃᕃ 60947-1 © IEC: 2004.ᕄ By plugging is understood stopping or reversing the motor rapidly by reversing motor primary connections while the motor is running.ᕅBy inching (jogging) is understood energizing a motor once or repeatedly for short periods to obtain small movements of the driven mechanism.Category Typical ApplicationsRelevant IEC Product Standard Nature of Current — ACAC-1Non-inductive or slightly inductive loads, resistance furnaces 60947-4-1AC-2Slip-ring motors: starting, switching off60947-4-1AC-3Squirrel-cage motors: starting, switching off motors during running 60947-4-1AC-4Squirrel-cage motors: starting, plugging ᕄ , inching ᕅ 60947-4-1AC-5a Switching of electric discharge lamp controls 60947-4-1AC-5b Switching of incandescent lamps 60947-4-1AC-6a Switching of transformers 60947-4-1AC-6b Switching of capacitor banks60947-4-1AC-7a Slightly inductive loads for household appliances and similar applications 61095AC-7b Motor-loads for household applications61095AC-8a Hermetic refrigerant compressor motor control with manual resetting of overload releases 60947-4-1AC-8b Hermetic refrigerant compressor motor control with automatic resetting of overload releases 60947-4-1AC-12Control of resistive loads and solid-state loads with isolation by optocouplers 60947-5-1AC-12Control of resistive loads and solid-state loads with optical isolation 60947-5-2AC-13Control of solid-state loads with transformer isolation 60947-5-1AC-14Control of small electromagnetic loads 60947-5-1AC-15Control of AC electromagnetic loads60947-5-1AC-20Connecting and disconnecting under no-load conditions 60947-3AC-21Switching of resistive loads, including moderate overloads60947-3AC-22Switching of mixed resistive and inductive loads, including moderate overloads 60947-3AC-23Switching of motor loads or other highly inductive loads 60947-3AC-31Non inductive or slightly inductive loads60947-6-1AC-33Motor loads or mixed loads including motors, resistive loads and up to 30% incandescent lamp loads 60947-6-1AC-35Electric discharge lamp loads 60947-6-1AC-36Incandescent lamp loads60947-6-1AC-40Distribution circuits comprising mixed resistive and reactive loads having a resultant inductive reactance60947-6-2AC-41Non-inductive or slightly inductive loads, resistance furnaces 60947-6-2AC-42Slip-ring motors: starting, switching off60947-6-2AC-43Squirrel-cage motors: starting, switching off motors during running 60947-6-2AC-44Squirrel-cage motors: starting, plugging ᕄ , inching ᕅ 60947-6-2AC-45a Switching of electric discharge lamp controls 60947-6-2AC-45b Switching of incandescent lamps60947-6-2AC-51Non-inductive or slightly inductive loads, resistance furnaces60947-4-3AC-52a Control of slip ring motor stators: 8 h duty with on-load currents for start, acceleration, run 60947-4-2AC-52b Control of slip ring motor stators: intermittent duty60947-4-2AC-53a Control of squirrel-cage motors: 8 h duty with on-load currents for start, acceleration, run 60947-4-2AC-53b Control of squirrel-cage motors: intermittent duty 60947-4-2AC-55a Switching of electric discharge lamp controls 60947-4-3AC-55b Switching of incandescent lamps 60947-4-3AC-56a Switching of transformers 60947-4-3AC-56b Switching of capacitor banks60947-4-3AC-58a Control of hermetic refrigerant compressor motors with automatic resetting of overload releases: 8 h duty with on-load currents for start, acceleration, run60947-4-2AC-58b Control of hermetic refrigerant compressor motors with automatic resetting of overload releases: intermittent duty60947-4-2AC-140Control of small electromagnetic loads with holding (closed) current ≤0,2 A, e.g. contactor relays60947-5-2For more information visit: AP03407008EApplication NotePage 6Effective: December 2007Use of IEC Contactors in UL, CSA and NEC Regulated ApplicationsTable 3. Examples of Utilization Categories for Low-Voltage Switchgear and Controlgear ᕃ (Continued)ᕃ 60947-1 © IEC: 2004.ᕄ By plugging is understood stopping or reversing the motor rapidly by reversing motor primary connections while the motor is running.ᕅBy inching (jogging) is understood energizing a motor once or repeatedly for short periods to obtain small movements of the driven mechanism.Category Typical ApplicationsRelevant IEC Product Standard Nature of Current — AC and DCA Protection of circuits, with no rated short-time withstand current 60947-2B Protection of circuits, with a rated short-time withstand current60947-2 Nature of Current — DCDC-1Non-inductive or slightly inductive loads, resistance furnaces60947-4-1DC-3Shunt-motors: starting, plugging ᕄ , inching ᕅ , Dynamic breaking of motors 60947-4-1DC-5Series-motors: starting, plugging ᕄ , inching ᕅ , Dynamic breaking of motors 60947-4-1DC-6Switching of incandescent lamps60947-4-1DC-12Control of resistive loads and solid-state loads with isolation by optocouplers 60947-5-1DC-12Control of resistive loads and solid-state loads with optical isolation 60947-5-2DC-13Control of electromagnets 60947-5-1DC-13Control of electromagnets60947-5-2 Nature of Current — ACDC-14Control of electromagnetic loads having economy resistors in circuit 60947-5-1DC-20Connecting and disconnecting under no-load conditions 60947-3DC-21Switching of resistive loads, including moderate overloads60947-3DC-22Switching of mixed resistive and inductive loads, including moderate overloads (e.g. shunt motors)60947-3DC-23Switching of motor loads or other highly inductive loads (e.g. series motors)60947-3DC-31Resistive loads60947-6-1DC-33Motor loads or mixed loads including motors 60947-6-1DC-36Incandescent lamp loads60947-6-1DC-40Distribution circuits comprising mixed resistive and reactive loads having a resultant inductive reactance60947-6-2DC-41Non-inductive or slightly inductive loads, resistance furnaces60947-6-2DC-43Shunt-motors: starting, plugging ᕄ , inching ᕅ , Dynamic breaking of DC 60947-6-2DC-45Series-motors: starting, plugging ᕄ , inching ᕅ, Dynamic breaking of DC 60947-6-2DC-46Switching of incandescent lamps60947-6-2AP03407008E For more information visit: Application NoteEffective: December 2007Page 7Use of IEC Contactors in UL, CSA and NEC Regulated ApplicationsConclusionBecause various standards differ in design requirements, testing, andapplication categories of contactors, it is important to understand the selection criteria of the governing standards in order to select the right contactor. Selecting the right contactor is critical to ensure appropriate application and performance at the minimum cost.Eaton Corporation Electrical Group1000 Cherrington Parkway Moon Township, PA 15108United States877-ETN CARE (877-386-2273)© 2007 Eaton Corporation All Rights Reserved Printed in USAPublication No. AP03407008E/CPG December 2007UL is a registered trademark of Underwriters Laboratories Inc. CSA is a registered trademark of the Canadian StandardsAssociation. NEC is a registered trademark of the National Fire Protection Association, Quincy, Mass. Cutler-Hammer and Eaton are federally registeredtrademarks of Eaton Corporation.。

CS Application GuideAs network bandwidth doubles every 18 months (Edholdm’s law), provisions have to be made to distribute thisadditional workload. Whereas years ago, 10Gb or 40Gb backbones were sufficient, many networks are now hosted on an absolute minimum of 100Gb, with 400Gb quickly following. As the transition to 400Gb backbones occur, standards bodies created the new CS connector specification which increases the number of duplex optical links by approximately 40% per rack unit (RU) designation. Designed to allow two duplex connectors in both of the 400G transceiver form factors (QSFP-DD and OSFP), the CS interface was developed as a key part of the industry’s effort to enable higher density high-speed solutions.The QSDP-DD and OSFP MSA (multi-source agreement) specifications defines a new cage/connector system with an additional row of contacts providing an eight-lane electrical interface, while still maintaining backwards compatibility with today’s four-channel QSFP28 modules (via an adapter for OSFP).The applications for the CS interface include but are not limited to; usage in patch cables, as well as cassette/breakout scenarios for both single and multimode fiber types.The Information Contained In This Application Guide Is Intended As A Guide For Use By Persons Having Technical Skill At Their Own Discretion And Risk. Before Using Any Panduit Product, The Buyer Must Determine The Suitability Of The Product For His/Her Intended Use And Buyer Assumes All Risk And Liability Whatsoever In Connection Therewith. Panduit Disclaims Any Liability Arising From Any Information Contained Herein Or For Absence Of The Same.Much of the need for a new form factor connector is due to the continued search for higher density in today’s modern data center applications. The smaller width of a CS adapter allows an increased quantity of connectors in the same RU footprint, and the decreased height allows for additional vertical space between adapters. Thedecreased height enables increased physical access to the adapter release mechanism, which is normally an issue with highly dense LC duplex patch fields. For example, a 1 RU enclosure with duplex LC cassettes will max out at 144 Fibers, whereas the same enclosure can accept up to 216 fibers (using 36-fiber,18 port double width CS cassettes), or 192 fibers (using 16-fiber, 8-port standard width CS cassettes).DensityFigure 1: Port density of duplex LC vs CS Application for 1RU enclosure§ LC Jumpers and Cassettes § 8-Port – Single Wide Cassette § 144 Fibers/RU§ CS Jumpers and Cassettes§ 18-Port – Double Wide Cassette § 216 Fibers/RUIn addition to 400Gb direct attach applications, CS also supports multiple structured cabling and breakout scenarios using MSA standards.Supported Applications2Structured CablingFigure 2: (2) x 8-Fiber MPO to (8) CS Connectors (16-Fibers)Figure 3: (3) x 12-Fiber MPO to (18) CS Connectors (36-Fibers)400G Structured Cabling(using existing MPO12 Infrastructure and universal polarity cassettes, MMF)400G Structured Cabling(using existing MPO12 Infrastructure and universal polarity cassettes, double-wide SMF)3Break OutFigure 4: Review of 400Gb SR8: (1) x 400G SR8 to (4) of 2 x 50G SR Breakout Application (MPO24)Figure 5: Review of 400Gb SR4: (2) x 100Gb SR4 to (8) x 25G SR OR (2) x 200Gb to (8) x 50G SR)Supported Applications (continued)400G SR8 Break Out2 x 100G or 200G SR4 Break Out400G SR82 of 100G SR4 OR 2 of 200G SR48 x 50G SR8 of 25G SR (for 100G Break Out) OR 8 of 50G SR (for 200G Break Out)CS Offering© 2020 Panduit Corp. ALL RIGHTS RESERVED.FBAG04--SA-ENG10/2020WORLDWIDE SUBSIDIARIES AND SALES OFFICESFor a copy of Panduit product warranties, log on to /warrantyPANDUIT US/CANADA Phone: 800.777.3300PANDUIT EUROPE LTD. London, UKPhone: 44.20.8601.7200PANDUIT JAPAN Tokyo, JapanPhone: 81.3.6863.6000PANDUIT SINGAPORE PTE. LTD. Republic of Singapore Phone: 65.6305.7575PANDUIT AUSTRALIA PTY. LTD. Victoria, Australia Phone: 61.3.9794.9020PANDUIT LATIN AMERICA Guadalajara, Mexico Phone: 52.33.3777.6000ContactCustomerServicebyemail:**************or by phone: 800.777.3300Visit us at For more informationCS Patch CablesCS HD Flex ™ Cassettes1 – Fiber Product F = Fiber2 – Fiber TypeZ = OM4 50/125µm 9 = OS2 9/125µm 3 – Fiber Count 2 = 2 fibers 4 – Cable TypeR = Round 2.0mm5 – Jacket TypeL = LSZH (Low Smoke Zero Halogen) R = OFNP (Plenum)6 – Connector Type – End A U = LC Duplex Uniboot Z = CS Duplex Connector7 – Connector Variant N = No variant8 – Connector Type – End B Z = CS Duplex Connector9 – Connector Variant N = No variant10 – Performance/Construction O = Optimized IL (A-B) N = Ultra (A-B)11 – Other N = No variant 12 – Unit of Length M = Meters F = Feet13, 14, 15 – Length 001-050Character Examplep a r t n u m b e rExample: F92RPZNZNONF003 = Fiber OS2, 2-fiber, 2mm cable, plenum rated, CS to CS, optimized IL, 3 feetNote: For hybrid cords, the CS connector is always on End B.Figure 6: CS Patch Cable Ordering SelectorFigure 7: CS HD Flex ™Cassettes Options。

Power Charger Calibration Platform Application NoteD/N：AN0516EOverviewIn the charger application area such as for electric bicycles and electric tools etc.manufacturers often have to make adjustments to the products before leaving the factoryto ensure that the charger output voltage and current values are within specifications. Thetraditional way of doing this is by using calibration fixtures which use fixed value orvariable resistors to determine the required resistance value. This method, in addition tothe labour costs also results in increased production times which have a major influenceon the product overall costs.The HT45F5Q-2 charger ASSP MCU, which includes a fully integrated battery chargermodule and EEPROM, can be used together with an automatic calibration fixture tocorrect the charger output voltage and current values, whose parameters can then bestored in the device’s internal EEPROM. This application note will explain how toautomatically correct the HOLTEK Charger ASSP MCU, such as the HT45F5Q-2, usingsuch a calibration fixture. A suitable calibration fixture can be designed in consultationwith this application note.Functional DescriptionCharger Adjustment ReasonsDuring charger volume production, the actual output voltage and currents produced mayresult in the charger being out of spec due to the product components tolerances (R2, R5and R6 in the figure below) as well as other reasons.Charger PrinciplesThe HOLTEK charger ASSP MCU has a fully integrated battery charger module. Theexample here uses the HT45F5Q-2 as an example. The internal DAC1 output iscompared with the voltage divider output, or the internal DAC0 is compared with the R2current signal. The internal OPA outputs will switch the opto-coupler which in turn willchange the Current Mode PWM IC output. In this way the required constant voltage or constant current can be obtained. When the charger is powered on, the MCU will first check whether it is connected to the calibration fixture through a 1-Wire communication method to confirm whether it should enter the calibration mode. If the connection is successful, the calibration will start and the correction value will be stored in the EEPROM. Then when the charger is powered up each time, the MCU will load the EEPROM updated calibration values.Fig 1. HT45F5Q-2 Charger Application Circuit DiagramCalibration Fixture Hardware DescriptionHoltek charger calibration fixture - uses the HT66F2390 as an example.1. AC/DC power supply circuit: AC 110V to DC 12V and 5V for use by the calibrationfixture, controls relay (K1) output to the charger AC power supply.2. ADC reference voltage circuit: The external TL431 (D5) is used as the MCU A/Dreference voltage (V REF), with a variable resistor (VR2) added. Users can manually adjust the ADC reference voltage by 4.0V to reduce the error.3. Charger voltage detection circuit: In the Normal Mode, this will detect the voltage of thecharger and allow the LCM to display the voltage value. In the Test Mode, the voltage is applied to B+/B-, and allows the LCM to display the voltage value. Manually adjust the detection voltage using the variable resistor VR1 to ensure the measurement accuracy of the charger voltage.4. Charger current detection circuit: Use the current sense IC (U1) to measure current andoutput voltage value to the MCU A/D.5. Level Shift control circuit: The 5V signal is used to control the 12V relays (K1~K3)through the voltage converter IC (U4).6. Load switching circuit: Use ceramic resistors (R1, R2) for the charger load.7. Charger connection circuit: The charger's AC power input is provided by the calibrationfixture (AC Output). The charger's DC power output is detected by the calibration fixture (DC IN). The charger's TRx and the calibration fixture communicate using single-wire communication.Since the output voltage of the charger is charging C1, B+ and B- are equal to the high voltage potential. If there is no Zener D4 voltage regulation to 5.1V and an R3 current limit, the high voltage potential will be directly injected into the MCU A/D pin which will cause damage.Calibration Fixture Circuit DiagramCalibration Fixture and Charger Connection InstructionsDuring calibration, the charger needs to be connected to the calibration fixture using the communication pins (TRx and GND), the AC input interface and the DC output interface (B+, B-). This is shown in the accompanying diagram. The AC main power supply is provided by the calibration fixture. In actual production, the contacts D, E and F can be used to allow customers to design their preferred connection method.Charger Calibration FixtureA: DC Output B+, B- ⇄D: DC Input B+, B-B: Signal TRx, GND ⇄E: Signal 1-Wire, GNDC: AC Input ⇄F: AC Output Connection DescriptionCharger and Calibration Fixture Wiring DiagramSoftware DescriptionUsers will have different requirements for the calibration protocol. The following is only aconceptual architecture but users can design the protocol format according to their ownrequirements. The following describes the software flow of the calibration fixture and thecharger.Charger Fixture Single Line Communication Protocol●Host: Calibration Fixture●Slave: Charger●Single-line communication definition: 1-bit total time of 1ms⏹Data 1: 700µs high-level, 300µs low-level⏹Data 0: 300µs high-level, 700µs low-level●Communication format:Instruction01H 02H 03H 04H 05H 06H 07H 55HFunction ConfirmConnection Start IncrementPowerDecrement PowerConfirmPowerAdjustment FailedCompleteClearEEPROM●Communication Timing Diagram⏹Normal CommunicationBus Master Signal Slave SignalFirst the host sends a start signal which is to pull down the bus for 18ms, after which it sends the commandAfter the slave detects a start signal it starts receiving commandsAfter the host sends the command, it will change into a receiver state. If the slave receives the correct command, it will send a start signal first and then reply to thesame host command after which the communication ends⏹Abnormal Condition – Example 1Bus Master Signal Slave SignalIf the host send out an erroneous instruction, the slave will not respond⏹Abnormal Condition –Example 2Bus Master Signal Slave SignalAfter the host sends an instruction, if for unknown reasons the slave does not respond, the host will execute a delay and then send the command again. Thedelay time is controlled by the host (greater than 30ms) and the same commandwill be sent up to 15 times.Calibration Fixture SoftwareAfter power-on, the calibration fixture waits for the user to press the start button and start communication. During communication, the fixture will switch on the charger power relay K1. After a 1 sec. charger stabilisation time, a communication command is sent for the charger to enter the calibration mode. If successful the charger will return a signal. If the communication has not been successful after the maximum permitted time is exceeded, it will be determined that the communication has failed or that the charger is not connected. The LCM will display a connection failure message and will then wait for the user to press the button again to re-communicate.When the communication is successful, the calibration fixture displays the correction information and will start the calibration procedure. When the fixture is being calibrated, the load relays, K2 and K3, are sequentially turned on and the battery load is simulated by the cement resistors. Through the resistor voltage divider, R6 and VR1, and current measurement IC, U1, the charger voltage or current measurement is performed separately. After each measurement, an increment or decrement command is sent, after which the charger will adjust the DAC to change the output power. When the calibration requirements are met, the charger is instructed to store the DAC parameters to the EEPROM and perform the next stage of the calibration process until all calibrations have been completed. Then it will turn off all relays, K1~K3, and display a calibration completed message. Each calibration stage has a maximum number of corrections equal to 20 times. If the number of corrections exceeds this, the correction will be determined to have been unsuccessful.Charger SoftwareFor three seconds after power-on, the charger will continuously detect whether the calibration fixture requires calibration. If a communication command from the calibration fixture is not received within this time, it will enter the charger mode. If a communication command is received and communication command successfully returned, the calibration program will be started.At the beginning of the calibration, the charger adjusts the integrated DAC (increment or decrement) according to the calibration fixture command, thereby adjusting the CV and CC values until the calibration is complete after which the DAC values are written into the EEPROM to complete the calibration program. Then wait for the charger to power up again but this time do not enter the calibration program. The charger will read the correction values in the EEPROM to update the DAC, and then start executing the normal charger program. Each calibration stage has a maximum number of corrections equal to 20 times. If the number of corrections exceeds this, the correction will be considered to be unsuccessful and no adjustment will take place until another correction command is received.Charge FlowchartCalibration Fixture Flowchart● Calibration Fixture Step Description⏹ Step 1: After the fixture is powered on, select the charger type to be calibrated, press the start button, turn on the charger power relay (AC Output), and send a connection command.⏹ Step 2: Wait for a return command and check that the time has not been exceeded and confirm that the charger has entered the calibration mode. If communication cannot be established with the calibration fixture then the calibration process will stop.⏹ Step 3: Connect the required load in the charging mode, measure the charger output status and the charger to adjust the DAC mode to fine tune the output voltage or current.⏹ Step 4: When the charger output voltage or current meets requirements, the charger is instructed to save the correction value to the EEPROM and displays a calibration success. If the calibration has not completed within the maximum correction time, the charger is instructed to skip this calibration item and display a calibration failure. ⏹ Step 5: Repeat steps 3 and 4 until all voltage and current calibration items have been corrected. ● Charger Step Description⏹ Step 1: Initialise the settings after the charger is powered on and receive the connection command.⏹ Step 2: The charger establishes communication with the calibration fixture and enters the calibration mode. If communication cannot be established with the calibration fixture, the default value in the EEPROM will be kept and returned to the charger operating mode.⏹ Step 3: Start the calibration process.⏹ Step 4: Send a correction command according to the calibration fixture to adjust the DAC mode and fine tune the output voltage or current.⏹ Step 5: Send the completion command according to the calibration fixture to complete the point correction at this stage. If successful, the DAC value is stored in the EEPROM. If it fails, the point correction is skipped and the next calibration item will be executed.⏹ Step 6: Repeat steps 4 and 5 until the calibration fixture sends a calibration end command to end the calibration process.Select Type DisplayCalibration DisplayCalibration Complete DisplayConnection Failed Display●Calibration fixtures are preset to four calibration points: floating voltage charging,constant voltage charging, trickle current charging and constant current charging.Taking a 48V lead-acid battery as an example, note the following process:⏹Floating voltage charging (FV): Constant voltage charging, used for self-dischargemaintenance after the battery has been fully charged, and can also be trickle charged.⏹Constant voltage charging (CV): Constant voltage charging, supplementing the partthat has not been fully charged after constant current charging.⏹Trickle charge (TC): Constant small current charging for when the battery has beendeep-discharged, a small current can re-activate the battery.⏹Constant current charging (CC): Constant current charging to prevent rapid batterytemperature rise which can reduce battery life and charging efficiency●The correction fixture voltage and current AD value calculation formula is as follows:⏹AD voltage value calculation: AD VBAT=4096V REF×�V BAT×VR1R6+VR1�Example: 59V AD voltage value: AAAA VVVVVVVV=40964×�59VV×1kk20kk+1kk�=2876=BB3CC HHNote：Demo Board R6=20k , VR1=1kk, V REF=4.0V、V BAT= charging voltage 59V ⏹AD current value calculation: AAAA II VV VVVV=4096VV RRRRRR×(0.185×II VV VVVV)Example: 0.2A AD current value: AAAA II VV VVVV=40964×(0.185×0.2AA)=37=25 HHNote：Demo Board R6=20k , VR1=1kk, V REF=4.0V, I BAT= Charging Current0.2A●Correct the calibration fixture data, register setup values are shown below:Calibration StepsSetup Values Decimal 16-bit hexFloating VoltageCharging (FV)=55V 2681 0A79HConstant VoltageCharging (CV)=59V 2876 0B3CHTrickle Current Charging(TC)=0.2A 37 0025HConstant CurrentCharging (CC)=2.0A 378 017AHParameter CalculationThe charger output voltage and current are measured and assessed by the MCU ADC on the calibration fixture. The output voltage signal is read from the 20kΩ and 1kΩ resistors voltage divider. The preset resistors are R6and VR1, which are used to convert the voltage signal. The formula is:AAAA VVVVVVVV=4096VV RR RRRR×�VV VV VVVV×VVVV1VV6+VVVV1�The charger output current is measured by the current sensing IC (ACS712ELCTR-05B-T) and supports a maximum current measurement of 5A, the detailed specifications are shown below. The current conversion voltage formula isAAAA II VV VVVV =4096VV RRRRRR×(0.185×II VVVVVV ) (as shown in the following red frame)Using the HT66F2390 12-Bit A/D with a reference voltage of 4.00V gives the following resolution:II RRRRRRRRRR RR RRRR RR RR =440960.185≅5.3mmAAACS712ELCTR-05B-T Specification TableCorrection Error CalculationThe corrected ADC value is compared with the tolerance maximum and minimum values. The error is corrected to achieve an accurate measurement of to achieve with the current sensing IC . However, the correction is still limited by each DAC. If the corresponding voltage or current has exceeded the specification, the calibration fixture will not have met the calibration requirements even if the measurement accuracy is accurate.ADC value is within tolerance Each DAC step is too large for calibration● Using FV=55V as an example, the AD conversion value is 2655~2709 so a value between this can be takenParameterTheoretical ValueR 6 VR 1 Permitted Error ADC ConversionValue FV55V20k1kk+1% 2709 -1%2655● Using CC=2A as an example, the AD conversion value is 360~398 so a value between this can be takenParameterTheoretical ValuePermitted ErrorADC Conversion ValueCC2A+5% 398 -5%360ADC valueCorrection fixture load component selectionThe calibration fixture uses cement resistors to simulate the battery load. The resistor voltage is used to measure the charger output voltage, and a current sensing IC measures the charger output current. The choice of cement resistance should pay attention to the resistance and power ratings. For example, if the output voltage of the charger is 60V and the output current is 2A, the resistance value should be 30Ω (R=V/I), and the rated power must be 120W (P=I2R). However, when taking into account the loading time during the calibration process, the power should be multiplied by the ratio of the use time. If the time ratio is 1/5, the resistance power can be reduced to about 24W.Comparison of advantages and disadvantages between automatic calibration fixture and traditional calibration fixtureAutomatic Calibration Fixtures Traditional Calibration FixturesCalibration Type Single Click Calibration –savestimeManual Calibration – time consumingPeople required 1 person 2 or more peopleCalibration Accuracy Internal DAC provides accuratecalibration Limited due to external componentsCalibrationTime Less than 10 sec./fixture Greater than 60 sec./ fixture ConclusionAfter the charger has been manufactured, due to external component tolerances or dueto long-term component depreciation, the charging parameters may experienceinaccuracies. For this reason a charger calibration tool is required to make the necessaryadjustments. This application note has provided a hardware description, softwaredescription, calibration parameter register names and parameter calculation formulas,supplemented by program flow charts and program step descriptions to allow users tounderstand the causes, principles, methods and points to note in a charger calibrationfixture. The fixture uses cement resistors as charger loads, however this can be changedto different load types by the user. The above can help users to quickly understand thedesign and which can be modified according to their own needs, or directly use thecalibration fixture provided by HOLTEK to reduce any difficulties due to manual correctionand improve the overall efficiency.Reference MaterialReference documents: HT66F2390 DatasheetFor more information consult the Holtek website: 。

Multiple m otors - s ingle d riveIntroductionThis document is to help with the installation and setup of a system with multiple motors that are run on a single drive at the same time. In this type of application, the drive can no longer protect individual motors so there are different system considerations as compared to a single drive/ single motor application. System considerations•Because the drive can’t protect individual motors each motor has to have it own thermal protection device. This device cannot be self-resetting and should be something you can turn off to be able to disconnect the motor if needed. This is normally a manual motor protector. It is not recommended to use fuses on the motor unless the fuses are monitored and will remove all 3 phases if it blows one phase.•When calculating the distance of the output run you have to add all of the cabling together. As an example, let’s say we have a single run between the drive and the distribution box of 100’. From there we go to 5 different motors and each of those runs is 25’. The equivalent output run would be 25+25+25+25+25+100=225’. We would need to protect the output for a 225’ output run. In the minimum any multiple motor system should have an output reactor on it. On the above example we would want to put a DV/DT filter on this to be safe.o0-150’ recommended output reactoro150-700’ recommended DV/DT filtero Above 700’ recommended sine filter (need to spec a sine filter capable of DC braking)•As with any drive installation the output cable should be run with a high quality VFD cable. This is to improve performance and reduce risk of adverse results.•For best results all motors should be the same make and model. These motors need to share the load as well as possible and any differences in the motors could cause an unbalanced load share. Drive setupThe following parameters are what you set for this type of setup:•Motor nameplate current: add all of the motor FLAs together and put this in the drive as nameplate current.•Motor nameplate voltage: this is the voltage off of the rating plate of the motor. If you want to output more or less voltage to the motor, it is better to use voltage at field weakening point and not by changing the motor nameplate voltage. The drive uses the motor nameplate information forcalculating a lot of things in the drive so if you skew this data you will make the drive calculatethings like power, torque and temperature incorrectly. As an example, if you have a 230V motor buta 208V input to the drive do not put the motor nameplate at 208, it should be 230. If you want thevoltage to increase up until the field weakening point we would change the voltage at fieldweakening point. In this case we would divide 208 by 230 which would give you 90%. You would put this in the drive for voltage at field weakening point.Multiple m otors - si ngle d riveApplication Note AP 040212ENEffective A pril 20202 EATON •Motor nameplate frequency: this should be taken directly off of the motor.•Motor nameplate speed: this should be taken directly off of the motor.•Power factor: this is taken directly off of the motor. If you can’t find it on the motor rating plate leave it as the default setting. This could potentially change power and torque calculations but hopefully it is close.•Current limit: should be set somewhere between 110-125%. I would start on the low end of this and increase it if we need more starting torque.•Minimum frequency: this is application specific. This will set the minimum reference you can set to the drive.•Maximum frequency: this is application specific. This is the maximum reference you can set to the drive.•Acceleration time: this is application specific. Preferably you set this to a value that will allow the drive to accelerate the application without going into a current limit.•Deceleration time: this is application specific. Preferably this is set to a value that will allow the drive to slow the application down without going into an overvoltage controller.•Start mode: start mode should be set to ramp to start. On multiple motors you can’t really use flying start because you can’t find magnetizing current on multiple motors at the same time. If there is the possibility of flying motors, we will need to use DC braking at start.•Stop mode: this will be application specific. Most of these applications will be fan banks which generally you will coast to stop. There are other applications where ramp to stop may be more preferable.•DC brake current: this is the current that you would use during DC braking. If we have the potential of flying motors when we start, we want to bring them to a stop before starting. I would start with about 30% of the combined FLA of all motors for this value. You do not want to go too high with this value in case motors are removed from the circuit you don’t want to put too much current to theremaining motors. If you go too low you may not be able to slow down the motors. The rough range would be between 30% to 75% of the combined FLA. If you go too high with this value you do not want to remove too many motors from the circuit without lowering this value.•Start DC brake time: this is going to depend on the application. We will use this in combination with the DC brake current to bring the motors to a stop before we start them. A good starting point would be about 60 seconds.•Voltage at field weakening point: this is the setting that you will use if you want the drive to output higher than motor nameplate voltage. If the input voltage is higher than the motor nameplate voltage you may want to use this voltage. You do this by increasing this number above 100%. As anexample, let’s say your input voltage is typically 490VAC. Your motor nameplate is 460V. With default settings the drive will output 460VAC at 60Hz. If we want to output the 490VAC at 60Hz instead of 460V we would take our input voltage and divide it by our motor nameplate voltage and put this in for this value. 490/460=106%Setup of b raking at s tartIf you have an application where it is possible for the motors to be moving when the drive starts you will need to use DC braking at start. You can’t use flying start because the motors are not synced with each other so the drive will not be able to find what speed the motors are at because they are all at different speeds. The way to set this up is to do the following:•The best way to watch the system is normally using the trendplotter on the HMAX or SVX series of drives or the powerexpert tool for DG1 series. This way you can look at multiple readings at once on your laptop. You can do this through the keypad but on the SVX and HMAX series you can record the readings which makes it easier to look at all the data.•Set DC braking current to about 30% of FLA.*•Set DC braking time at start to 60 sec.*•If you are using ramp to stop change to coast to stop.•Start the application with all of the motors attached. Ramp up to full speed if possible.Multiple m otors - s ingle d rive Application Note AP 040212ENEffective A pril 2020EATON 3•Stop the application and then immediately restart it. Time how long it takes the motors to come to a stop.•If the motors did not come to a complete stop before the drive tried to start the motors, you should either increase the braking current or increase the braking time. The caution with this is if you have to go high in braking current you have to be cautious about removing motors. Motors will take more than 100% current for a short period of time but as an example if you have 6 motors in the bank and you have braking set to 75% of the combined FLA you probably would not want to remove more than 3 of the motors from the circuit without changing this current. If you removed 3of the motors from the circuit when you would start you would be putting 150% of FLA to the motors for the length of time you have the braking set for. This won’t hurt for motor for theamount of time we should be using for braking but if you remove 1 more motor that percentage now goes to 225% of FLA. This is getting into an area that you shouldn’t be running and if you go down to 1 motor you will now be at 450% of FLA. This will heat the motor and start to degrade the motor insulation along with the cabling insulation going to the individual motor.•If the motors stopped well before the drive restarts the motors, you will probably want to decrease the braking time. I would recommend setting this about 5 to 10 seconds longer than it takes to stop the motors. This way if system characteristics change we have some leeway in the system.•Retry this after adjusting these settings to make sure everything looks okay while starting and stopping the application.•If you need ramp to stop change back to ramp to stop.*If you are doing this on an HMAX drive you do not have DC braking at start. You will need to use pre-magnetizing current and pre-magnetizing time to get the same results.Motor p rotection d evice Each motor on the system has to be protected individually because the drive cannot tell the difference between motors and know where all of the current is going on the output.This protection has to be something that will not auto-reset. We do not want the motor to bereconnected to a drive that is running. This will cause a lot of current to be drawn off of the drive and will trip the drive. Normally manual motor protectors (MMP) are used for this because you can also manually remove the motor from the circuit if you need to. Fuses should not be used to protect the motors unless there is something that will recognize a blown fuse and remove the other 2 phases to the motor.When you set the protection devices you do not set them for the service factor of the motor. The service factor of the motor is for a clean sinusoidal output. The drive does not put out a cleansinusoidal output so there are harmonics involved. This makes the service factor of the motor 1.0 due to the extra heating. This is what you would set your protection devices for. You may want to give it a little extra to stop any false tripping, but you do not want to use the service factor rating of the motor.Multiple m otors - s ingle d rive Application Note AP040212ENEffective A pril 2020Additional h elpIn the US or Canada: please contact the Technical Resource Center at 1-877-ETN-CAREor 1-877-326-2273 option 2, option 6.All other supporting documentation is located on the Eaton web site at /DrivesEaton1000 Eaton BoulevardCleveland, OH 44122 USA© 2020 EatonAll Rights ReservedPrinted in USAPublication No. AP040212ENApril 2020Eaton is a registered trademark.All other trademarks areproperty of their respectiveowners.。

Chinese GAAP, US GAAP and IFRS Comparison: Revenue Recognition1. Relevant accounting standards1) 企业会计准则第14号—收入及应用指南2) 企业会计准则第15号—建造合同及应用指南3) FASB Accounting Standard Codification 605 Revenue Recognition4) IAS 18 Revenue5) IAS 11 Construction Contracts6) IFRIC 13 Customer Loyalty Programs7) SIC 31 Revenue-barter Transactions Involving Advertising Services2. Differences between IFRS and CASCAS basically adopts all the principles from IFRS under this topic.One difference comes from the fact that IFRS deals with non-monetary exchange in each involved Standards, while CAS has one separate standard (CAS 7) to cover all the non-monetary exchange.1) IFRS 9 Revenue requires disclosure of the amount of revenue arising from exchanges of goods or services included in each significant category of revenue.2) CAS 7 Non-monetary Exchange requires disclosure of the fair value of non-monetary assets exchanged, the carrying amount of non-monetary assets given up, and the gain or loss from the exchange.3. Differences between IFRS and US GAAP1) SummaryA. The argument that IFRS is principle-based while US GAAP is rule-based very possibly arises from the area of revenue recognition.Up to end of 2008 (i.e. the official 2009 bound volume), IFRS has two primary revenue standards and three revenue focused interpretations. The broad principles laid out are generally applied without further guidance or exceptions for specific industries.In contrary, US GAAP consists of a significant number of standards (now all piled into the Codification system) originally issued by FASB, APB/ARB, AICPA and SEC. A strong ground of general principles is lacking, while highly detailed and often industry-specific guidelines are abundant.B. There are also some differences which are beyond the scope of different approaches (principle-based or rule-based).a) For example, percentage-of-completion method is generally acceptable for service transactions under IFRS, while the same method is not acceptable under US GAAP (unless the service transaction is within the scope of construction/production typecontract). Instead, US GAAP has detailed rules to separate multiple-element arrangement into units of accounting, while IFRS only provides very general rule as to separate identifiable elements according to economic substance.b) As another example, percentage-of-completion and completed-contract method are applied under appropriate circumstances (The two methods are not acceptable alternatives for same circumstances), while only percentage-of-completion method is allowed under IFRS.Under this title, my usual approach of item by item comparison is not practical. Therefore, I’ll try to demonstrate the diffe rent approaches taken by the two systems for only some major issues.(To give folks who are not fa miliar with this area some taste, I’ll discuss US GAAP software revenue recognition under a separate title.)2) Revenue recognition criteria -- generalA. IFRSIn IFRS system, two primary revenue standards capture all revenue transactions within four broad categories, with recognition criteria laid out for each category.a) Revenue from sale of goods shall be recognized when all of the following have been satisfied:i. The entity has transferred to the buyer the significant risks and rewards of ownership;ii. The entity retains neither continuing managerial involvement to the degree usually associated with ownership nor effective control over the goods sold;iii. The amount of revenue can be measured reliably;iv. It is probable that the economic benefits associated with the transaction will flow to the entity;v. The costs incurred or to be incurred in respect of the transaction can be measured reliably.b) Revenue from rendering of services shall be recognized using percentage-of-completion method (which is not permitted under US GAAP, unless the arrangement falls within the scope of construction-type or production type contract), if all criteria below are met:i. The amount of revenue can be measured reliably;ii. It is probable that the economic benefit associated with the transaction will flow to the entity;iii. The stage of completion of the transaction at the end of the reporting period can be measured reliably; andiv. The costs incurred for the transaction and the costs to complete the transaction can be measured reliably.When the outcome of the transaction cannot be estimated reliably, revenue shall be recognized only to the extent of the expenses recognized that are recoverable.c) Revenue arising from the use by others of entity assets shall be recognized When criteria below are met:i. It is probable that the economic benefits associated with the transaction will flow to the entity;ii. The amount of the revenue can be measured reliably.d) Revenue from construction contracti. When the outcome of a construction contract can be estimated reliably, contract revenue and contract costs shall be recognized respectively, using percentage-of-completion method, by reference to the stage of completion at the end of reporting period.ii. When the outcome of a construction contract cannot be estimated reliably, revenue shall be recognized only to the extent of contract costs incurred that it is probable will be recoverable and contract costs shall be recognized as expense in the period of incurrence (Costs that are not probable of being recovered shall be expensed immediately).B. US GAAPa) The new codification system adopts the two factors to be considered in revenue recognition from Statement of Financial Accounting Concepts No. 5:i. Being realized or realizable> Revenue is realized when products are exchanged for cash or claims to cash.> Revenue is realizable when related assets received or held are readily convertible to known amounts of cash or claims to cash.ii. Being earnedRevenue is considered to have been earned when the entity has substantially accomplished what it must do to be entitled to the benefits represented by the revenues.However, both general and industry-specific rules barely seem to be built upon these two factors (not contradictory to them though). Instead, AICPA SOP 97-2 (Software Revenue Recognition) has significant influence way beyond the industry (for example, the obvious influence on SEC SAB Topic 13), especially in the area where several products and services are sold together for a single price.b) SEC SAB Topic 13 (required for SEC registrants only) deliberates on the criteria to be met so that revenue is realized or realizable and earned.i. Persuasive evidence of an arrangement exists;ii. Delivery has occurred or services have been rendered;iii. Seller’s price to buyer is fixed or determinable;iv. Collectability is reasonably assured.Detailed application guidance is given for each criterion.3) Unit of accountingA. Under IFRSa) Recognition criteria should be applied to separately identifiable components of a transaction in order to reflect substance of the transaction.However no further instructions are given on how revenue is allocated among separate components.b) Recognition criteria should be applied to two or more transactions when they are linked in such a way that the commercial effect cannot be understood without reference to the series of transactions as a whole.B. Under US GAAP, in an arrangement with multiple deliverables, the delivered item(s) shall be considered a separate unit of accounting if all of the following criteria are met:a) The delivered item(s) has value to the customer on a standalone basis. The item(s) has value on a standalone basis if they are sold separately by any vendor or the customer could resell it on a standalone basis (existence of observable market is not required).b) There is object and reliable evidence of the fair value of the undelivered item(s).c) If the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered is considered probable and substantially in the control of the vendor.4) Combining and segmenting construction contractsBoth IFRS and US GAAP provide criteria for combining and segmenting construction contracts.A. Combining contractsa) Under IFRS, a group of contracts shall be treated as a single contract when:i. The group of contracts is negotiated as a single package.ii. The contracts are in effect part of a single project with an overall profit margin.iii. The contracts are performed concurrently or in a continuous sequence.b) Under US GAAP, a group of contracts may be combined if all the following conditions exist:i. The group of contracts is negotiated as a single package.ii. The contracts are in effect part of a single project with an overall profit margin.iii. The contracts are performed concurrently or in a continuous sequence.iv. The contracts are performed under the same project management at the same location or at different locations in the same general vicinity.v. The contracts require closely interrelated construction activities with substantial common costs that cannot be separately identified with, or reasonably allocated to, the elements, phases, or units of output.vi. The contracts constitute in substance an agreement with a single customer.B. Segmenting contractsa) Under IFRS, a contract shall be segmented when:i. Separate proposals have been submitted for each asset.ii. Each asset has been subject to separate negotiation and the contractor and customer have been able to accept or reject the part relating to each asset of the contract.iii. The costs and revenues of each asset can be identified.b) Under US GAAP, a contract may be segmented if either:i. All of the following steps are taken and are documented and verifiable:> The contractor submitted bona fide proposals on separate components and on entire project.> The customer had the right to accept the proposals on either basis.> The aggregate amount of the separate proposals approximates the amount of the entire project.ii. Or all the following criteria are met:> The terms and scope clearly call for separable phases or elements.> The separable phases or elements are often bid or negotiated separately.> The market assigns different gross profit rates to the segments.> The contractor has a significant history of providing similar services to other customers under separate contracts for each significant segment to which a profit margin higher than overall margin is ascribed.> The significant history with customers who have contracted for services separately is one that is relatively stable in terms of pricing policy.> The excess of sum of separate element prices over the price of the total project is clearly attributable to cost savings incident to combined performance.> The similarity of services, prices of contract segments, and prices of such services to other customers should be documented and verifiable.5) Accounting methods for construction contractsA. Under IFRS, only percentage-of-completion method is allowed.B. Under US GAAP,a) Percentage-of-completion method is considered preferable in circumstances in whichi. Reasonably dependable estimates (of the extent of progress toward completion, contract revenues, and contract costs) can be made andii. the following conditions exist:> contracts executed by parties normally include provisions that clearly specify the enforceable rights regarding goods or services to be provided and received by the parties, the consideration to be exchanged, and the manner and terms of settlements.> The buyer can be expected to satisfy all obligation under the contract.> The contractor can be expected to perform all contractual obligations.b) Completed-contract method is considered appropriate under circumstances wheni. Lack of dependable estimates or inherent hazards cause forecasts to be doubtful; orii. Financial position and results of operation would not vary materially from those resulting from use of percentage-of-completion method.iii. Accounting for contracts of short duration.6) ClaimThe two systems both require that the claim amount be reliably estimated for recognition as revenue. However, they differ in when the claim will result in additional contract revenue.A. Under IFRS, claims are included in contract revenue only when:a) Negotiations have reached an advanced stage such that it is probable that the customer will accept claim; andb) The amount that it is probable will be accepted by the customer can be measured reliably.B. Under US GAAP, revenue from a claim may be recorded only if it is probable that the claim will result in additional contract revenue and if the amount can be reliably estimated. It goes on to define that the two requirements are satisfied by the existence of all the following conditions:a) The contract or other evidence provides a legal basis for the claim, or a legal opinion has been obtained stating that under the circumstances there is a reasonable basis to support the claim.b) Additional costs are caused by circumstances that were unforeseen at the contract date and are not the result of deficiencies in the contractor’s performance.c) Costs associated with the claim are identifiable or otherwise determinable and are reasonable in view of the work performed.d) The evidence supporting the claim is objective and verifiable, not based on management’s feel or on unsupported representations.US GAAP also allows the practice which records revenues from claims only when the amounts have been awarded or received.。

·指南与共识·中国非肌层浸润性膀胱癌治疗与监测循证临床实践指南（2018 简化版）中国研究型医院学会泌尿外科学专业委员会，中国医疗保健国际交流促进会泌尿健康促进分会，中国医疗保健国际交流促进会循证医学分会，国家重点研发计划微创等离子手术体系及云规划解决方案项目组【关键词】 非肌层浸润性膀胱癌；经尿道膀胱肿瘤切除术；卡介苗；治疗与监测；循证临床实践指南Treatment and surveillance for non-muscle-invasive bladder cancer in China: an evidence-based clinical practice guideline (2018 simplified version)Urological Association, Chinese Research Hospital Association (CRHA); Urological Health PromotiveAssociation, China International Exchange and Promotive Association for Medical and Health Care (CPAM);Evidence-Based Medicine Association, China International Exchange and Promotive Association for Medical and Health Care (CPAM); The Project Team for Minimally Invasive Plasma Kinetic System and Cloud Planning Solution, The National Key Research and Development Program of ChinaCorresponding author: WANG Xinghuan, Email: wangxinghuan1965@; HE Dalin, Email: hedl@【Key words 】 Non-muscle-invasive bladder cancer; Transurethral resection of bladder tumor; Bacillus Calmette-Guérin ; Treatment surveillance; Evidence-based clinical practice guideline1 指南的目标用户泌尿外科医师及护理人员、全科医生及护理人员、从事膀胱癌治疗的临床医学教学和研究人员。