2023-UWMSN-00027-RFB Amendment 2.pdf

ShopUW+ Sourcing Event No.: 2023-UWMSN-00027-RFB – AMENDMENT #1

QUESTIONS AND ANSWERS

Q1: What application are these VFDs being used for?

A1: We are using the VFDs in HVAC applications. Please refer to the attached DFD Master Specs for additional information.

Q2: Are you looking for an S-Flex type of VFD?

A2: We are not looking for bids on S-Flex type VFDs.

DFD Project No.

23 05 14-1

SECTION 23 05 14 1

VARIABLE FREQUENCY DRIVES 2

BASED ON DFD MASTER ELECTRICAL SPEC DATED 9/8/22 3

This section has been written to cover most (but not all) situations that you will encounter. 6 Depending on the requirements of your specific project, you may have to add material, delete 7 items, or modify what is currently written. The Division of Facilities Development expects 8 changes and comments from you. 9

The consultant shall carefully edit this section and coordinate the variable frequency drive (VFD) 11 and line reactors to the equipment being specified in the Div. 23 specifications. The VFD will be 12 furnished by the Div. 23 contractor(s) and be installed by the Div. 26 contractor. Coordinate VFD 13 Div. 26 requirements with the Div. 26 consultant. 14

PART 1 GENERAL 17

Applicable provisions of Division 1 shall govern all work under this Section 19

SCOPE 21

This section includes variable frequency drives, bypass starters, and line reactors. Included are the following 22 topics: 23

PART 1 - GENERAL 24

Scope 25 Related Work 26 Reference 27 Standards 28 Submittals 29 Operating and Maintenance Data 30 Equipment Startup 31 Warranty 32

PART 2 - PRODUCTS 33

Manufacturers 34 Design and Construction 35 Performance Requirements 36 Control Features 37 Protection Features 38 Diagnostics 39 Quality Assurance Tests 40 Bypass Equipment 41 AC Input Line Reactors 42 Output Line Filters 43

PART 3 - EXECUTION 44

Variable Frequency Drives (VFD) 45 Construction Verification Items 46 Functional Performance Testing 47 Agency Training 48

RELATED WORK 50

Section 01 91 01 or 01 91 02 – Commissioning Process 51 Section 23 08 00 – Commissioning of HVAC 52 Section 22 30 00 – Plumbing Equipment 53 Section 23 12 13 - Facility Fuel-Oil Pumps 54 Section 23 21 23 - Hydronic Pumps 55 Section 23 34 00 - HVAC Fans 56 Section 23 64 15 - Water Cooled Chillers 57

23 05 14-2

Section 23 65 00 - Cooling Towers 1 Section 23 73 13 - Modular Indoor Central-Station Air-Handling Units 2 Section 26 05 26 - Grounding and Bonding for Electrical Systems 3 Section 26 05 29 - Hangers and Supports for Electrical Systems 4 Section 26 05 53 - Identification for Electrical Systems 5 Section 26 27 02 – Equipment Wiring Systems 6

REFERENCE 8

Applicable provisions of Division 1 govern work under this section. 9

STANDARDS 11

ANSI/IEEE 519-2014 Guide for Harmonic Control and Reactive Compensation of Static Power Converters 12

SUBMITTALS 14

Submit shop drawings and product data under provisions of Division 1, General Conditions of the Contract. 15 Include physical, electrical, and performance characteristics of each variable frequency drive and associated 17 components, including dimensions; weight; input and output performance; voltage, phase, current and 18 overcurrent characteristics; installation instructions; protective features; wiring and block diagrams 19 indicating specified options; electrical noise attenuation equipment where required to meet the criteria 20 specified; line side voltage notch wave form and line side current harmonics; certified efficiency versus load 21 and speed curves; and required operating environment. 22

OPERATION AND MAINTENANCE DATA 24

All operations and maintenance data shall comply with the submission and content requirements specified 25 under section GENERAL REQUIREMENTS. 26 Delete the following if there are no additional requirements. 28 In addition to the general content specified under GENERAL REQUIREMENTS supply the following 29 additional documentation: 30

1. [A/E and commissioning provider to define detailed operation and maintenance data 31 requirements for equipment specifications added to this section.] 32

EQUIPMENT STARTUP AND AGENCY TRAINING 34

Provide the services of a factory trained and certified technician to approve the installation; start-up, test, and 35 adjust for proper operation of the unit(s). Upon completion of the equipment startup, submit a complete 36 manufacturer’s field report, including startup and test log, signed by the factory trained technician. 37 Coordinate with the Temperature Control Contractor and the Balancing Contractor. The startup shall be 38 coordinated with Division 26. Electrical and shall be completed within ten (10) working days from the startup 39 date as set by the DFD representative. 40

WARRANTY 42

The warranty shall be for a period of twenty-four (24) months from the date of project Substantial 43 Completion. Further, the warranty shall include all parts, labor, travel time, administrative costs, overhead, 44 travel expenses, technical support and any and all other costs to provide the warranty service. 45

PART 2 PRODUCTS 48

MANUFACTURERS 50

ABB, Toshiba, Danfoss, Trane/Danfoss, GE, Emerson, Yaskawa, Eaton/Cutler Hammer, Mitsubishi, Allen 52 Bradley 53

The consultant shall identify any VFDs to be installed in plenum areas and specify 55 plenum rated devices in those areas. 56

DESIGN AND CONSTRUCTION 57

23 05 14-3

The unit shall be variable torque, modular design for control of the motors as specified in Division 23 and 1 rated at the motor full load nameplate amps. 2 The unit shall be U.L. listed, solid state, microprocessor based with a pulse width modulated (PWM) output 4 wave form (none others are acceptable). 5 Mechanical designer should coordinate this requirement with the electrical designer. 7 The VFD package shall have a short circuit current rating (SCCR) of [XX] [65] [100] kA. 8 The VFD shall employ a full wave bridge rectifier and capacitors to minimize the ripple of the rectified 10 voltage to maintain near constant DC voltage. Insulated gate bipolar transistors (IGBT’s) shall be employed 11 as the output switching device. 12 The VFD package shall contain the equivalent of 5% impedance to reduce harmonic distortion. The 5% 14 equivalent impedance shall be provided in the form of a DC choke, an input AC line reactor in each phase, 15 or a combination of the two methods. 16 Control circuitry shall be plug-in, plug-out modular basis with a corrosion resistant coating on printed circuit 18 boards. 19 Units to be suitable for an operating environment from 0°C to 40°C temperature and humidity up to 90% 21 non-condensing. 22 Electrically and physically isolate control circuitry and conductors from power circuitry and power 24 conductors. Control conductors and power conductors shall not be run in the same pathway. 25 The unit enclosure shall be NEMA [1, 12] as required for the application minimum and all components shall 27 be fully factory assembled and tested prior to leaving the manufacturing facility. 28

A manual bypass is required on VFD installations where adequate redundancy of 30 mechanical systems does not exist, and a bypass is required to make the building 31 functional on VFD failure. This determination should be made based on evaluating the 32 mechanical system, what it is serving, the consequences of a failure, and economic 33 impact on the project. There may be some cases when a manual bypass is not economical 34 (such as in very small motor applications). If a bypass is provided, it is the AE’s 35 responsibility to design the mechanical system it is serving with proper sizing, 36 mechanical components, etc. to operate under full speed without damage or failure of 37 the mechanical system. The AE shall schedule the VFD and bypass requirements on the 38 mechanical plans. 39

Include the following operating and monitoring devices mounted on the front cover: 41 A fused disconnect switch to de-energize the drive [and bypass circuit] with door interlocked handle 42 and lock-open padlocking provisions. 43 Operating mode selector switch marked "hand-off-auto". 44 Manual speed adjustment via keypad, mounted on the door. 45 Manual bypass selector switch to select power through drive or bypass (if a bypass is provided). 46

[Provide a manual bypass circuit and bypass starter to transfer from variable frequency drive operation to 48 bypass operation (if a bypass is provided).] 49

PERFORMANCE REQUIREMENTS 51

Units shall be suitable for input power of electrical system as scheduled on the drawings ±10%, 3 phase, 60 52 Hertz nominal. 53 Use a current limiting control device to limit output current to 110% continuous for one minute; also refer to 55 Protection Features in this section. Full load output current available from drive shall not be less than motor 56

23 05 14-4 nameplate amperage. The full load amp rating of the VFD shall not be less than the values indicated in the 1 NEC Table 430-150. 2 Output power shall be suitable for driving standard NEMA B design, three phase alternating current induction 4 motors at full rated speed with capability of 6:1 turndown. 5 Additional performance capabilities to include the following: 7 Ride through a momentary power outage of 15 cycles, 8 Start into a rotating load without damage to drive components or motor, 9 Capable of automatic restart into a rotating load after a preset, adjustable time delay 10 following a power outage 11 Input power factor: Min 0.95 throughout the speed range 12 Minimum efficiency: 95% at 100% speed, 85% at 50% speed 13

The consultant shall insert the following Harmonic Analysis requirement for projects 15 where total motor horsepower/ KVA utilizing VFD’s is equal to or greater than 1/3 of 16 building transformer KVA rating. This shall include fans, pumps, chillers, elevators 17 packaged equipment, etc. The consultant shall utilize the following: For Science/ 18 Laboratory buildings, 3% THD-v and 8% TDD Harmonic Distortion requirements shall 19 be specified. For all other building projects, 8% THD-v and 8% TDD Harmonic 20 Distortion requirements shall be specified. Consult with DFD if there are questions if a 21 building is considered a Science/Laboratory building. 22

HARMONIC ANALYSIS 24

VFD manufacturer shall perform harmonic analysis at building Main Switchboard, to demonstrate that the 25 limits specified in IEEE-519-2014 are satisfied. [VFD manufacturer shall perform harmonic analysis at 26 generator supply terminals to demonstrate that harmonic current and voltage distortion limits indicated are 27 not exceeded while system is supplied with generator power.] 28 VFDs provided under other specification sections (chillers, elevators, packaged equipment, etc.) shall also 30 be included in analysis. Contractor shall be responsible for gathering VFD information from other 31 specification sections and providing it to VFD manufacturer performing analysis. 32 Analysis shall be computer generated and perform Fourier analysis of system. Results shall list current and 34 voltage amplitudes of all harmonics up to 50th level at secondary of service transformer. A summary shall 35 detail percent total harmonic distortion for voltage and total demand distortion for current. 36 Analysis shall assume maximum transformer loading of 75% of nameplate value. Analysis shall assume 38 maximum generator loading of 75% of nameplate value. 39 Analysis shall assume motor loading of 75% of nameplate full load amps. 41 Analysis shall assume 5.75% impedance at service transformer for the purposes of calculating available fault 43 current. Assume infinite utility fault capacity for the purposes of this study only. 44 Successful contractor must provide required data for VFD manufacturer to complete harmonic analysis. 46 Information shall include short circuit amperes capability; distribution transformer kVA and impedance; 47 length, size and number of wires per phase to distribution equipment feeding VFDs; wire data to VFDs from 48 distribution equipment; wire data to motor from VFD; and motor nameplate data. 49 VFD manufacturer is responsible for cost of all equipment required to meet harmonic limits identified below, 51 based on IEEE-519 standards. Equipment, which can be provided, includes input line reactors, DC bus 52 reactors, harmonic filters, passive filters, and active filters. 53 The Total Harmonic Voltage Distortion at the building switchboard shall be limited to [3][8] % THD-v, and 55 the Total Harmonic Current Distortion shall be limited to 8 % TDD. 56

23 05 14-5

CONTROL FEATURES 2

Use control circuits compatible with input signal from temperature control system in the automatic mode and 3 from manual speed control in the manual mode. Vary motor speed in response to the input control signal. 4 Include components necessary to accept the signal from the temperature control system in the form that it is 5 sent. Refer to Division 23 00 00. 6 Include the following additional control features: 8

• Hand-Off-Automatic (HOA) selector switch to select local or remote start/stop and speed control 9

• Analog input, selectable 0-10v or 4-20 mA, for automatic control from the temperature control system 10

• Local speed control at the VFD 11

• Adjustable acceleration and deceleration rate so that the time period from start to full speed and from 12 full speed to stop can be field adjusted 13

• Adjustable minimum and maximum speed settings for both automatic and manual modes of operation 14

• Manual transfer bypass circuit 15

• Field adjustment of minimum and maximum output frequency 16

• Two (2) sets of programmable form “C” contacts for remote indication of variable frequency drive 17 condition. Note: default programming to be set for “Drive Run & Fault”. 18

• Illuminated display keypad. 19

• External Fault indicator 20

• One (1) input for a N.O. dry contact type input for a 2-wire remote start/stop 21

• One (1) input for a N.C. dry contact type input for external faults: (freezestats, fire alarm, smokes, etc). 22

This input shall be factory wired to prevent both the VFD and bypass starter operation when external 23 fault is present. 24

• One (1) N.O. dry contact output for proving motor status. This output shall be programmed to detect 25 belt or coupling break that would remove the load from the motor by using sensed torque of the motor. 26 The dry contact will open on loss of load or VFD being off. 27

• PID control loop capable of VFD control from an external device connected to a VFD analog input. 28

• When specified in the 23 09 93 sequence of operations, provide a VFD input and output for shutoff 29 damper control that shall operate as follows: When the fan is remotely or locally commanded to start, 30 VFD contact shall energize the shutoff damper to open the damper. The damper position end switch 31 shall be wired to a run permissive input on the VFD and enable the VFD to start when the damper end 32 switch provides the damper is open. This feature shall be provided for both inverter and bypass 33 operation (if bypass option is provided). 34

For VFD’s that are to be integrated into the building automation system the following paragraph should 36 be used. Determine by discussing with Agency staff and DFD, if this type of interface is currently being 37 utilized on the Agencies existing buildings/campus. If so, it should be provided. Determine if the system 38 the VFD is integrated into requires a different protocol such as LonWorks FTT-10, Modbus RTU, or 39 Modbus TCP. If so, modify the protocol from BACnet MSTP to the appropriate protocol. 40 The VFD controller shall convert VFD information into the BACnet MSTP protocol that will be compatible 42 with the building direct digital energy management system (EMS) supplied on the project. This output shall 43 be through a serial interface port capable of two-way communication with the building EMS provided on this 44 project. Final connection shall not require any additional intermediate gateway devices to provide throughput 45 of data. The following data shall be provided at a minimum: 46

• Fault condition 48

• Speed 49

• Amperage 50

• Frequency 51

• Voltage 52

• Bypass status (if supplied) 53

PROTECTION FEATURES 57

23 05 14-6

Use electronic protection circuitry in the power circuits to provide an orderly shutdown of the drive without 1 blowing fuses and prevent component loss under the following abnormal conditions: 2 Activation of any safety device; 3 Instantaneous overcurrent and/or over voltage of output; 4 Power line overvoltage and undervoltage protection; 5 Phase loss; 6 Single and three phase short circuiting; 7 Ground faults; 8 Control circuit malfunction; 9 Overtemperature; and 10 Output current over limit. 11 Provide the following additional protective features: 13

• Input transient overvoltage protection up to 3000 volts per ANSI 37.90A; 14

• DC bus fusing which limit the rate of rise of the DC bus current and de-energizes the drive at a 15 predetermined current level; 16

• Fusing for the control circuit transformer; 17

• Grounded control chassis; and 18

• Devices and/or control circuitry to ensure that the variable frequency drive and bypass starter are not 19 both energized and driving motor simultaneously. 20

DIAGNOSTICS 22

Provide an English character display (no error codes) with indicators for the following: 23 Phase loss 24 Ground fault 25 Overcurrent 26 Overvoltage 27 Undervoltage 28 Over temperature 29 Overload 30 DC bus status 31

QUALITY ASSURANCE TESTS 33

Use a factory heat stress test to verify proper operation of all functions and components under full load. 34 Field performance test of variable frequency drives to determine compliance with this specification will be 36 performed at the DFD's discretion and may include any specified feature, including operation of protective 37 devices through a simulated fault. Contractor will pay for initial testing. Should drive be found deficient by 38 this testing, drive manufacturer will be required to make any and all changes necessary to bring unit(s) into 39 compliance with the specified performance and demonstrate this performance by retesting. Cost of changes 40 and retest will be by this contractor. 41 Variable frequency drive manufacturer or designated representative to perform a field test of each drive, in 43 the presence of the DFD's representative, for the following items: 44

• Provide general inspection to verify proper installation; 45

• Demonstrate drive reaction to simulated power interruptions of two seconds and sixty seconds; 46

• Demonstrate adequate protection during switching from variable frequency drive operation to bypass 47 starter operation and back again; 48

BYPASS EQUIPMENT 50

Bypass Starters: 51

The bypass starters for 208 volt motors, 20 HP and less; and 480 volt motors, 40 HP and less, shall 52 be NEMA rated across-the-line magnetic starter type. 53

23 05 14-7

The bypass starters for 208 volt motors, 25 HP and more; and 480 volt motors, 50 HP and more, 1 shall be NEMA rated solid state reduced voltage starting type. 2

Bypass Configuration: 4

Provide one main fused disconnect switch to de-energize both the drive and bypass circuit. Provide 5 a drive input disconnect switch to allow the drive to be isolated while the bypass circuit is energized. 6 Provide one output drive contactor and one output bypass contactor. The two output contactors shall 7 be electrically interlocked to allow only one contactor to be closed at any one time. 8

Provide motor overload protection in the bypass circuit. 10 Provide bypass equipment in a common enclosure with the VFD or, if not available, in a separate enclosure. 12

AC INPUT LINE REACTORS 14

When needed to comply with the requirement for 5% equivalent impedance, furnish and factory install AC 15 input line reactors. 16 Line reactors shall be installed in each phase of the AC input side of the VFD and mounted within a common 18 enclosure with the VFD. 19 Line reactor shall be a three phase inductor, iron core, 600V, Class H insulation, 115 degree C rise, copper 21 windings with screw type terminal blocks. 22 Include the following section if 460VAC drives on the project have output line lengths over 120 feet. It is 24 not desirable to locate VFD’s outside and we would prefer adding an output line filter and locating the 25 VFD inside. As a rule, do not exceed line lengths of 300 feet for 460VAC motors. Specifically call out 26 what drives will require output filters to eliminate confusion if line lengths are indeterminate. 27

OUTPUT LINE FILTER 29

Provide a three phase dV/dT output filter for any 460VAC drive with output line length of over 120 feet or 30 as specified. 31

PART 3 EXECUTION 34

VARIABLE FREQUENCY DRIVES 36

Install where indicated on drawings and in accordance with approved submittals and manufacturer's 37 published recommendations. Installation to be by the Division 26 00 00 - Electrical contractor. 38 Input power wiring shall be installed in a separate conduit, output power wiring shall be installed in a separate 40 conduit and control wiring shall be installed in a separate conduit. Do not mix input power, output power, or 41 control wiring in a common conduit. Separate conduits for input and output power wiring shall be provided 42 for each motor. Input and output power wiring for more than one motor shall not share a common conduit. 43 Power wiring shall be furnished and installed by the Div. 26 contractor. If provided, do not mount output 44 line filter above the drive. 45 Motor status relay shall be programmed to detect belt or coupling loss for fans and pumps. This shall use 47 motor torque to determine when the load is lost and shall be set to show status loss whenever the VFD is at 48 the lowest programmed speed and the belt or coupling loss occurs. This shall be tested by the VFD setup 49 technician in conjunction with the Division 23 control contractor and commissioning agent. 50

The consultant is to coordinate with the Division 26 00 00 - Electrical consultant to 52 ensure that VFD requirements, characteristics, and locations are correctly shown on the 53 mechanical and electrical plans. 54

Control signal for drive will be provided under Division 23. 55

23 05 14-8

Temperature Control Contractor will furnish and install the required temperature control wiring in metal 1 conduit and in accordance with Division 26 00 00 - Electrical of this specification. 2

CONSTRUCTION VERIFICATION ITEMS 4

Contractor is responsible for utilizing the construction verification checklists supplied under specification 5 Section 23 08 00 in accordance with the procedures defined for construction verification in Section 01 91 01 6 or 01 91 02. 7

FUNCTIONAL PERFORMANCE TESTING 9

Contractor is responsible for utilizing the functional performance test procedures supplied under specification 10 Section 23 08 00 in accordance with the procedures defined for functional performance testing in Section 01 11 91 01 or 01 91 02. 12

AGENCY TRAINING 14

All training provided for agency shall comply with the format, general content requirements and submission 15 guidelines specified under Section 01 91 01 or 01 91 02. 16 Contractor to provide factory authorized representative and/or field personnel knowledgeable with the 18 operations, maintenance and troubleshooting of the system and/or components defined within this section for 19 a minimum period of [XX] hours. 20

END OF SECTION 23