2024 Design and Construction Standards - Section 5A - Variable Frequency Drives

10 SECTION 5A – VARIABLE FREQUENCY DRIVES 1 Design 11 Description of Work 12 Provide a ____ HP adjustable frequency drive for the motor for ___________ A thermal magnetic line circuit breaker with external operating handle shall be provided in the enclosure 13 Adjustable frequency drive is referred to in the contract documents as a “ VFD , ” “ AFD , ” or “ AC Drive ” 14 This section provides specification requirements for adjustable frequency drives or variable speed drives identified herein as AC Drives for use with NEMA ® MG31 inverter - duty motors or with NEMA asynchronous Design B motors having an appropriate output filter 15 The manufacturer shall furnish , field test , adjust , and certify all installed AC Drives for satisfactory operation 16 Any exceptions or deviations to this specification shall be indicated in writing and submitted with the quotation 17 References A ANSI ® NFPA ® 70 – National Electrical Code ® NEC ® B CSA ® C222 No 14 - M91 – Industrial Control Equipment C IEC 61000 – Electromagnetic Compatibility D NEMA 250 – Enclosures for Electrical Equipment E NEMA ICS7 – Industria Control and Systems Adjustable Speed Drives F NEMA ICS 71 – Safety Standards for Construction and Guide for Selection Installation and Operation of Adjustable Speed Drives G UL ® 50 – Enclosures for Electrical Equipment H UL 98 – Disconnect Switches I UL 507 – Electric Fans J UL 508 – Industrial Control Equipment K UL 508C – Power Conversion Equipment L UL 991 – Safety Tests for Safety Related Controls Employing Solid State Devices M OSHA ® 191095 – AC Drive Controller Acoustical Noise N IBC ® – International Building Code ® O ASCE SEI 7 ® – Seismic Performance Requirements P ICC ES AC156 – Shake - Table Test Acceptance Criteria Q IEEE – Standard 519 , Guide for Harmonic Content and Control 18 Submittals A Six copies of the shop drawings shall be furnished for the engineer’s approval prior to factory assembly of the AC Drives These drawings shall consist of elementary power and control wiring diagrams and enclosure outline drawings The enclosure drawings shall include front and side views of the enclosures with overall dimensions and weights , conduit entrance locations , and nameplate legends Section 5A - 1 VARIABLE FREQUENCY DRIVES 2024 RevisionPageSECTION 5A – VARIABLE FREQUENCY DRIVES B Standard catalog sheets shall be furnished for each different horsepower rated AC Drive , showing voltage , horsepower , maximum current ratings , and recommended replacement parts with part numbers C A harmonic distortion analysis shall be performed by the manufacturer based on documentation supplied by the contractor The engineering documentation shall consist of one - line diagrams , utility short circuit information , distribution transformer information kVA , Z , and X R ratio and emergency standby generator kW and subtransient reactance data if applicable The harmonic distortion analysis report shall be part of the approval drawing process , submitted to the engineer for approval D Prior to completion and final acceptance of the project , the Contractor shall furnish and install “ as - built ” wiring diagrams for each VFD and bypass starter If applicable These final drawings shall be plastic laminated and securely placed inside each VFD and starter door and included in the O & M manuals E Identify service and part suppliers in the local area within 150 miles Service technicians must be certified to work on the specific VFD installed 19 Warranty A Warranty shall be 24 months from the date of Owner acceptance of the project The warranty shall include all parts , labor , travel time and expenses There shall be 365 24 support available via a toll - free phone number 110 Quality Assurance A The manufacturer of the AC Drive shall be a certified ISO 9001 facility B The AC Drive and all associated optional equipment shall be UL Listed according to UL 508C Power Conversion Equipment or UL 508A Industrial Control Panel A UL label shall be attached inside each enclosure as verification C The AC Drive shall be designed , constructed , and tested in accordance with UL , CSA , NEMA , IBC , ASCE SEI 7 , and NEC standards D 154 Every power converter shall be quality assurance tested with an AC induction motor under load conditions and subjected to a dielectric voltage - withstand test , with all enclosed devices mounted and wired , prior to shipment E Quality assurance documentation shall be furnished to verify successful completion upon written request of the engineer 111 Available Space for Installation of Motor Controllers A The Contractor shall provide VFDs that will fit in the available space shown allocated in each electrical building Any required equipment that is not mounted inside the VFD enclosure shall be mounted on walls and wired external to the enclosure by the Contractor 112 Testing Section 5A - 2 VARIABLE FREQUENCY DRIVES 2024 RevisionPageSECTION 5A – VARIABLE FREQUENCY DRIVES A All printed circuit boards shall be completely tested and burned - in before being assembled into the completed motor controller The motor controller shall then be subjected to a preliminary functional test , burn - in , and computerized final test The burn - in shall be at 104 degrees F 40 degrees C , at full rated load , on a motor Drive input power shall be continuously cycled for maximum stress and thermal variation B All testing and manufacturing procedures shall be ISO 9001 certified C VFD manufacturer shall have an analysis laboratory to evaluate the failure of any component The failure analysis lab shall allow the manufacturer to perform complete electrical testing , x - ray of components and analyze failures within the component 2 Materials 21 Manufactures A The AC Drive shall be provided by Square D A Division of Schneider Electric , ABB , Danfoss , or approved equal Substitutions must be submitted in writing three weeks prior to original bid date with supporting documentation demonstrating that the alternative manufacturer meets all aspects of the specifications herein B Alternate control techniques , other than pulse width modulated PWM control , are not acceptable C Manufacturer must provide a written guarantee that they will provide repair parts and technical support for no less than a period of 10 yrs after the end of production of the unit 22 General Description A The AC Drive shall convert the input AC mains power to an adjustable frequency and voltage as defined below and indicated on the drawings or motor control schedules 1 For all AC Drives rated , the AC Drive manufacturer shall use a 6 - pulse bridge rectifier design , unless a 12 or 18 - pulse is required to control harmonic distortion Active front end drives as also acceptable unless specific application requires alternative methods as designed by the engineer The diode rectifiers shall convert fixed voltage and frequency , AC line power to fixed DC voltage The power section shall be insensitive to phase rotation of the AC line 2 Line reactors , DC bus reactor , or harmonic suppressors will be provided if needed for effective harmonic mitigation B The output power section shall change fixed DC voltage to adjustable frequency AC voltage This section shall use insulated gate bipolar transistors IGBT or intelligent power modules IPM as required by the current rating of the motor 1 For AC drives an output filter is required to maintain a maximum peak voltage at the motor below 1000volts regardless of cable lengths Acceptable types would be KLC series as manufactured by TCI or approved equal Substitutions must be submitted in writing three weeks prior to original bid date with supporting documentation demonstrating that the alternative manufacturer meets all aspects of the specifications herein Section 5A - 3 VARIABLE FREQUENCY DRIVES 2024 RevisionPageSECTION 5A – VARIABLE FREQUENCY DRIVES 23 Construction A The AC Drive shall be mounted in a Type 1 , Type 12 12K , Type 3R enclosure with an externally operated disconnect device for indoor applications only B A mechanical interlock shall prevent an operator from opening the AC Drive door when the disconnect is in the on position Another mechanical interlock shall prevent an operator from placing the disconnect in the on position while the AC Drive door is open It shall be possible for authorized personnel to defeat these interlocks C Provisions shall be made for locking all disconnects in the Off position Provisions for additional padlocking shall be made by the customer using an approved lockout tagout device D Provisions shall be made for accepting a padlock to lock the enclosure door 24 Seismic Qualification A A certificate of compliance shall be provided for all wall - and floor - mounted enclosures to the seismic provisions of the IBC International Building Code and ASCE SEI 7 American Society of Civil Engineers Structural Engineering Institute Seismic Performance Requirements B The seismic ratings shall meet the site - specific requirements of the installed location as determined by the latest edition of IBC , NFPA 5000 , CBC California Building Code , and ASCE SEI 7 C Seismic code compliance testing shall be in accordance with ICC ES AC156 Shake - Table Test Acceptance Criteria protocol with an importance factor of at least 15 D All anchorage , lateral bracing , and mounting guidelines shall be specified with drive instruction documentation and or markings E The manufacturer shall exhibit a seismic qualification label on the equipment stating compliance to these requirements 25 Motor Data 26 The AC Drive shall be sized to operate the following AC motors and shall be defined to match the load schedules and the type of connections used between the motor and the load , such as a direct connection or a power transmission connection A Motor horsepower rating s B Motor full load ampere ratings coordinated to motor nameplate data C Motor synchronous speed 600 , 1800 , 1200 at 60 Hz determined by motor nameplate data D Motor utilization voltage 460VAC E Motor service factor 115 27 Application Data A The AC Drive shall be sized to operate a variable torque load B The speed range shall be from a minimum speed of 01 Hz to a maximum speed of 60 Hz Section 5A - 4 VARIABLE FREQUENCY DRIVES 2024 RevisionPagePage pageNumber5SECTION 5A – VARIABLE FREQUENCY DRIVES 28 Environmental Ratings A The AC Drive shall meet IEC 60664 - 1 and NEMA ICS - 1 Annex A standards B The AC Drive shall be designed to operate in an ambient temperature of - 10 to + 40 ° C + 14 to 104 ° F Type 3R shall be designed to operate from - 10 to + 50 ° C + 14 to 122 ° F C The storage temperature range shall be - 25 to + 65 ° C - 13 to + 149 ° F D The maximum relative humidity shall be 95 at 40 ° C 104 ° F , non - condensing with no dripping water , conforming to IEC 60068 - 2 - 3 E The AC Drive shall be rated to operate at altitudes less than or equal to 3,300 - feet 1000 meters without derating For altitudes above 3,300 - feet 1000 - meters , the manufacturer’s derating factors shall apply F The AC Drive shall conform to IEC 600721 - 3 - 3 - 3M3 Amplitude for Operational Vibration Specifications 29 Ratings A The AC Drive shall be designed to operate from an input voltage of 460 plus or minus 10 B The AC Drive shall operate from an input voltage frequency range of 47 – 63 Hz C The displacement power factor shall not be less than 095 lagging under any speed or load condition D The efficiency of the AC Drive at 100 speed and load shall typically not be less than 96 Efficiency shall vary with the power rating of the AC Drive E The variable torque rated AC Drive over - current capacity shall be 150 for one minute F The output carrier frequency of the AC Drive shall be randomly modulated depending on the Drive rating for low noise operation No AC Drive with an operable carrier frequency above 16 kHz shall be allowed G The output frequency shall be from 01 – 200 Hz H The AC Drive shall develop rated motor torque at 05 Hz 60 Hz base in a sensorless flux vector SVC mode using a standard induction motor without an encoder feedback signal 210 Protection A Upon power - up , the AC Drive shall automatically test for valid operation of memory , valid operation of option module , loss of analog reference input , loss of communication , dynamic brake failure , DC to DC power supply , control power , and the pre - charge circuit B The AC Drive shall be UL Listed according to UL 508C for use on distribution systems with 100,000 A available fault current The AC Drive shall have a coordinated short circuit rating designed to UL 508C and listed on the nameplate UL 508A industrial panels shall be rated per the specification of the customer C The AC Drive shall have protection against short circuits , protection between output phases and ground ; and protection between the logic and analog outputs Section 5A - 5 VARIABLE FREQUENCY DRIVES 2024 RevisionPagePage pageNumber6SECTION 5A – VARIABLE FREQUENCY DRIVES D The AC Drive shall have minimum AC under - voltage power loss ride - through of 200 milliseconds The AC Drive shall have the user - defined option of frequency fold - back to allow motor torque production to continue to increase the duration of the power - loss ride - through E The AC Drive shall have a selectable ride - through function that shall allow the logic to maintain control for a minimum of one second without faulting F The AC Drive shall have an auto restart function that shall provide programmable restart attempts for a fault condition other than a ground fault , short circuit , or internal fault condition The programmable time delay before restart attempts shall be unlimited G The AC Drive shall have a programmable deceleration mode for normal and fault conditions The stop modes shall include freewheel stop , fast stop , and DC injection braking H Upon loss of the analog process follower reference signal , the AC Drive shall enter a tripped condition and or operate at a user - defined speed set between software programmed low - speed and high - speed settings I The AC Drive shall have solid state I2t protection that is UL Listed and meets UL 508C as a Class 10 overload protection and meets IEC 60947 The minimum adjustment range shall be from 20 – 150 of the nominal output current rating of the AC Drive J A thermal switch with a user selectable pre - alarm shall provide the AC Drive with a minimum of 60 seconds delay before over - temperature fault K The heat - sink shall have bonded fin , moulded , or block - milled construction for maximum heat transfer L The AC Drive shall have a fold - back function that shall automatically anticipate a controller overload condition and fold back the frequency to avoid a fault condition M The output frequency of the AC Drive shall be software enabled to fold back when the motor is overloaded N There shall be three skip frequency ranges with hysteresis adjustment that can each be programmed independently , back to back , or overlapping 211 Adjustments and Configurations A The AC Drive shall self - configure to the main operating supply voltage and frequency Operator adjustments shall not be required B Upon power up , the AC Drive shall automatically send a signal to the connected motor The stator resistance data shall be measured at rated current The AC Drive shall automatically optimize the operating characteristics according to the stored data C The AC Drive shall be factory preset to operate most common applications D A choice of at least two types of acceleration and deceleration ramps shall be available in the AC Drive software linear and S curve Other product specific curves may be available E The acceleration and deceleration ramp times shall be adjustable from 001 to at least 3,200 seconds F The volts per hertz ratios shall be user selectable to meet variable torque loads , normal , Section 5A - 6 VARIABLE FREQUENCY DRIVES 2024 RevisionPagePage pageNumber7SECTION 5A – VARIABLE FREQUENCY DRIVES and high - torque machine applications G The memory shall retain and record run status and fault type of at least the past four faults H Slip compensation shall be adjustable from 0 – 150 I The software shall have an “ Energy Saving ” function that shall reduce the voltage to the motor when the variable torque setting is selected A constant volts hertz ratio shall be maintained during acceleration The output voltage shall then automatically adjust to meet the torque requirement of the load J The AC Drive shall offer programmable DC injection braking that will brake the AC motor by injecting DC current and creating a stationary magnetic pole in the stator The level of current shall be adjustable between 10 and 100 of rated current and available from 10 to at least 20 seconds continuously For continuous operation after 30 seconds , the current shall be automatically reduced to 50 of the nameplate current of the motor K Sequencing logic shall coordinate the engage and release thresholds and time delays for the sequencing of the AC Drive output , mechanical actuation , and DC injection braking in order to accomplish smooth starting and stopping of a mechanical process 212 Graphical Display Terminal Interface A The graphic display terminal shall provide the ability in English to control , adjust , and configure the AC Drive All electrical values , bar charts , configuration parameters , I O assignments , application and activity functions , faults , local control , adjustment storage , self - test , and diagnostics shall be accessible through the terminal interface B The AC Drive model number , torque type , software revision number , horsepower , output current , motor frequency , and motor voltage shall be listed on the drive identification display as viewed on the graphic display terminal C At a minimum , the selectable outputs shall consist of speed reference , output frequency , output current , motor torque , output power , output voltage , line voltage , DC voltage , motor thermal state , drive thermal state , elapsed time , motor speed , machine speed reference , and machine speed D The graphic display terminal shall consist of programmable function keys The functions shall allow both operating commands and programming options to be preset by the operator A hardware selector switch shall lock out the graphic display terminal from unauthorized personnel E The graphic display terminal shall offer a simple to advanced user menu consisting of parameter setting , I O map , fault history , and drive configuration A software lock shall limit access to the main menu F The navigation scheme shall provide the ability to scroll through menus and screens , select or activate functions , or change the value of a selected parameter G An Escape key shall return a parameter to the existing value if an adjustment is not required and the value shall be displayed The escape function shall also return to a previous Section 5A - 7 VARIABLE FREQUENCY DRIVES 2024 RevisionPagePage pageNumber8SECTION 5A – VARIABLE FREQUENCY DRIVES menu display H A Run key and a Stop key shall command a normal start and stop as programmed when the AC Drive is in keypad control mode The Stop key must be active in all control modes I A user interface shall be available that is a WINDOWS ® based personal computer , serial communication link , or detachable graphic display terminal J The keypad and all door - mounted controls must be Type 12 or greater rated and made of corrosion resistant material 213 Control A External pilot devices may be connected to a terminal strip for starting stopping the AC Drive , speed control , and displaying operating status All control inputs and outputs shall be software assignable B A 2 - wire or 3 - wire control strategy shall be defined within the software The 2 - wire control shall allow automatic restart of the AC Drive without operator intervention after a fault or loss of power The 3 - wire control shall require operator intervention to restart the AC Drive after a fault or loss of power C The control power for the digital inputs and outputs shall be 120VAC D The internal power supply shall incorporate an automatic current fold - back function that protects the internal power supply if incorrectly connected or shorted The transistor logic outputs shall be current limited to 220 mA and shall not be damaged if shorted or if excess current is pulled E All logic connections shall be furnished on pull - apart terminal strips F There shall be two software assignable analog inputs with interference filtering The analog inputs shall be software selectable and shall consist of user - defined configurations x - y mA or x - y V G There shall be at least four software assignable logic inputs that shall be selected and assigned in the software The logic input assignments shall consist of forward , reverse , jog , plus minus speed 2 inputs required , set - point memory , preset speeds up to 8 inputs , auto manual control , controlled stop , terminal or keypad control , output contactor 2 inputs required , motor switching , and fault reset H There shall be at least one software assignable analog output with interference filtering The analog outputs can be selected and assigned in the software The analog output assignments shall be proportional to the following motor characteristics frequency , current , power torque , voltage , and thermal state The output signal shall be user - defined configurations x - y mA or x - y V I Two voltage - free Form C relay output contacts shall be provided One of the contacts shall indicate AC Drive fault status The other contact shall be user assignable J There shall be a hardware input output extension module that also provides interlocking and sequencing capabilities The module shall be fully isolated and housed in a finger - safe enclosure with pull - apart terminal strips The module shall add four logic inputs , two analog Section 5A - 8 VARIABLE FREQUENCY DRIVES 2024 RevisionPagePage pageNumber9SECTION 5A – VARIABLE FREQUENCY DRIVES inputs , two relay outputs , and one analog output All of the inputs and outputs shall be user assignable in the software as previously defined K The combination enclosure shall have the following optional 22mm door - mounted operators 1 Power On pilot light red 2 Drive Run pilot light green 3 Drive Fault pilot light yellow 4 Hand - Off - Auto selector switch 5 Manual speed potentiometer 214 Dynamic Braking Application Dependent Option A Provisions shall be made to protect the dynamic brake resistor against overload and over - current due to dynamic brake switch failure This protection must be resettable without replacement of fuses or other devices B The dynamic brake resistor shall be provided and connected to existing terminals on the AC Drive The resistor shall mount externally to the AC Drive enclosure An insulated gate bipolar transistor IGBT shall be provided in the AC Drive to switch excess regenerative energy to the braking resistor The braking resistor shall be of a size calculated to stop 6 times motor inertia at 15 per unit motor torque 215 O & M Manual A 1 hard copy & 1 electronic shall be delivered at the startup 3 Installation , Inspections and Tests 31 VFD Installation A The contractor shall install the drive in accordance with the recommendations of the VFD manufacturer as outlined in the installation manual Grounding shall be done as required to prevent the propagation of radio frequencies on the station wiring and into PLC equipment B The contractor shall complete all wiring in accordance with the recommendations of the VFD manufacturer as outlined in the installation manual 32 AC Drive Installation A Installation shall comply with manufacturers instructions , drawings , and recommendations B The AC Drive manufacturer shall provide a certified technical service representative to supervise the contractors installation , testing , and start - up of the AC Drive s furnished under this specification for a maximum total of 3 days The start - up service shall be quoted as a separate line item 33 Start - Up Section 5A - 9 VARIABLE FREQUENCY DRIVES 2024 RevisionPage0SECTION 5A – VARIABLE FREQUENCY DRIVES A Certified factory start - up shall be provided for each VFD by a factory authorized service center A certified start - up form shall be filled out for each drive with a copy provided to the Owner , and a copy kept on file at the manufacturer 34 Training A An on - site training course of one day training shall be provided by an authorized representative of the AC Drive manufacturing plant and or maintenance personnel and quoted as a separate line item 35 O & M Manual – 1 hard copy , 1 electronic END OF SECTION Section 5A - 10 VARIABLE FREQUENCY DRIVES 2024 RevisionPage