final 26 09 15 VFD.pdf

OFFUTT AIR FORCE BASE

(092036) 26 09 15-1 (Repair AHU O-Club, B462)

2010 by FEI

SECTION 26 09 15

VARIABLE FREQUENCY DRIVES

PART 1 - GENERAL

1.1 WORK INCLUDED

A. Extent of variable frequency drives work is indicated by drawings and schedules and by requirements of this section.

B. The variable frequency drives for this Project shall be of the pulse width modulated type.

C. Coordinate VFD requirements with kitchen exhaust hood control system specified in “Kitchen Ventilator

Hood Systems” Section 23 38 13. VFD’s serving make-up air handler and exhaust fans shall be fully ready for interface and incorporation into the kitchen exhaust hood control system.

1.2 QUALITY ASSURANCE

A. Manufacturer's Qualifications: Firms regularly engaged in manufacture of variable frequency drives, of types and capacities required, where products have been in satisfactory use in similar service for not less than five (5) years.

B. Installer's Qualifications: A firm specializing and experienced in variable frequency drive installations for not less than five (5) years.

C. Codes and Standards:

1. Electrical Standards: Provide electrical components of variable frequency drives which have been UL Listed and labeled, and comply with NEC Standards.

2. NEMA Compliance: Comply with NEMA Standards pertaining to components and devices.

3. ETL Compliance: Provide variable frequency drives with ETL approved label.

1.3 SUBMITTALS

A. Product Data: Submit manufacturer's technical product data, including rated capacities of selected model clearly indicated, weights, furnished specialties, contactors and accessories; and installation and start-up instructions. Submit manufacturer's assembly-type shop drawings indicating dimensions, weight loadings, required clearances and methods of assembly of components.

B. Coordination Data: Submit nameplate information for each motor to be operated by VFD.

C. Wiring Diagrams: Submit manufacturer's electrical requirements for power supply wiring for variable frequency drives. Submit manufacturer's ladder-type wiring diagrams for interlock and control wiring.

Clearly differentiate between portions of wiring that are factory-installed and portions to be field installed.

D. Operating Conditions: Submit manufacturer's printed information clearly stating ambient temperature requirement and carrier frequency at rated conditions.

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E. Maintenance Data: Submit maintenance data and parts list for each variable frequency drive, control, and accessory; including "Trouble-Shooting" Maintenance Guide. Include this data and product data in

Maintenance Manual.

1.4 DELIVERY, STORAGE, AND HANDLING

A. Handle variable frequency drives carefully to prevent damage, breaking, denting and scoring. Do not install damaged units or components; replace with new.

B. Store variable frequency drives in clean, dry place. Protect from weather, dirt, fumes, water, construction debris and physical damage.

C. Comply with manufacturer's rigging and installation instructions for unloading variable frequency drives and moving units to final location for installation.

PART 2 - PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS

A. Manufacturers: Subject to compliance with requirements, provide variable frequency drives of one (1) of the following:

1. Cutler-Hammer

2. General Electric

3. Grahm

4. Reliance

5. Square D

6. Toshiba

B. All VFD's shall be of the same manufacturer. Verify that the size of the equipment supplied by the selected manufacturer does not exceed the available mounting space.

2.2 GENERAL

A. Establish requirements for variable voltage variable frequency motor controls, for speed control of fans, blowers or pumps driven with AC motors.

B. Coordinate exact locations of all motors controlled from a VFD and provide motors rated for VFD operation. In addition, motors shall be suitable for across-the-line starting.

2.3 VARIABLE FREQUENCY MOTOR CONTROL

A. Pulse Width Modulation VFD:

1. The controller shall produce an adjustable AC voltage/frequency output. It should have an output voltage regulator to maintain correct output V/Hz. despite incoming voltage variations.

2. The VFD shall be of the Pulse-Width Modulated type and shall consist of a full-wave diode bridge converter to convert incoming fixed voltage/frequency/ to a fixed DC voltage.

3. The inverter output shall be generated by power transistors or IGBT's (isolated gate bipolar transistors).

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4. The logic control section shall be microprocessor based.

2.4 SPECIFICATION

A. Verify power input requirements with drawings.

1. Nominal input voltage +/ - 10%

2. Input frequency stability 48-62 HZ

B. Provide minimum 3% AC Input Line Reactor.

C. Output power; 3-phase, 1.5 to 60 Hz with variable voltage to give proper and efficient operation of variable torque load.

D. Displacement power factor - Minimum of 90% over the entire speed range.

E. VFD shall be rated for HP rating indicated on drawings. Additionally amp rating shall not be less than

National Electrical Code, Table 430-150 for corresponding HP size indicated. HP and current ratings noted above shall be minimum values after any/all derating factors such as frequency, elevation, ambient temperature, etc. have been applied. Ratings shall be based on 40C ambient temperature and a carrier frequency of 4,500 to 8,000 KHz.

F. Minimum overload capacity of 110% for one (1) minute.

2.5 MINIMUM REQUIREMENTS FOR CONTROL OPERATION

A. Fused input door interlocked disconnect.

B. Isolated 115VAC control transformer.

C. Annunciated or digital display and time stamp of the following fault and limit functions for:

1. Thermal overload relay trip.

2. Microprocessor self-check function.

3. Output overcurrent trip.

4. DC bus overvoltage trip.

5. Inverse time overload trip.

6. Heat sink overtemperature trip.

7. DC bus fuse open.

8. DC bus overvoltage (regen. limit).

9. Output ground fault.

10. Inverter ready light.

11. Inverter run light.

12. Power line on light.

2.6 MINIMUM REQUIRED STANDARD FEATURES

A. Provide input disconnecting means, either a switch or circuit breaker. Disconnects shall be capable of being locked in the open position.

B. Provide VFD input fuses rated for protection of semiconductors.

C. Door Mounted Components:

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1. Inverter run indication.

2. Digital speed (frequency or percent speed) and motor ammeter.

3. Manual speed adjustment.

4. Reset for fault and enable.

5. Manual / Auto reference selector.

6. Hand-Off-Auto (HOA) switch.

7. Annunciation as in Section 2.5.

D. DC bus charged indicator.

E. Current limit circuit active to prevent nuisance tripping during acceleration or run conditions.

F. Regeneration limit circuit active to prevent nuisance OV tripping during deceleration.

G. Minimum and maximum speed set, separate and non-interactive.

H. Power loss restart selectable for Auto Restart in auto mode only.

1. Automatic restart from undervoltage, power failure, or control fault.

I. Control shall protect VFD and motor load against overvoltage, undervoltage, and single phasing of main line power input.

J. Critical frequency lockout for up to two (2) points, available from 10% to 100% speed with at least a 6

Hz bandwidth.

K. Only non-filament type indicating lights may be used.

L. Control shall survive without component failure and annunciate, output phase to phase and phase to ground faults.

M. Loss of reference protection, VFD shall reset to predetermined minimum speed until such time as the control is commanded to stop or the analog reference returns to normal.

N. Control shall have available 15 selectable volts per hertz patterns.

O. Volts per hertz ratio shall be automatic, tracking motor load requirements to achieve most efficient operation within the parameters set by the volts per hertz pattern. Potentiometer adjustments not allowed.

P. VFD shall have adjustable automatic restart capabilities and be capable of starting into a spinning motor.

Q. Control must be capable of starting into a spinning motor and switching from inverter to bypass back to inverter without delay and without tripping off line of the inverter, also must be capable of stopping a motor rotating in the reverse direction and then accelerating that motor in the proper direction

R. All components must be supplied in an enclosure.

S. Manual Bypass Control. A bypass control shall be provided for the purpose of running the AC motor at full speed with line power while the VFD is being serviced. Bypass and drive shall be electrically interlocked. The VFD package shall be configured so that the VFD can be removed for service with the bypass control left in place. Motor load shall be protected by VFD fusing while operating in bypass.

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T. System shall have an adjustable setting to allow a power line dip ride through of four (4) cycles.

U. Up to four (4) programmable pre-set speeds.

V. Drive output reference signal, compatible with the temperature control system and the kitchen exhaust hood control panel:

1. 0 to 10 vdc

2. 4 to 20 ma

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine areas and conditions under which variable frequency drive systems are to be installed. Do not proceed with work until unsatisfactory conditions have been corrected in a manner acceptable to

Installer.

3.2 INSTALLATION OF VARIABLE FREQUENCY DRIVE SYSTEMS

A. General: Install system and materials in accordance with manufacturer's instructions and roughing-in drawings, and details on drawings. Install electrical components and use electrical products complying with requirements of applicable electrical specifications. Mount controllers at convenient locations and heights.

3.3 CLEANING

A. Cleaning: Clean factory-finished surfaces. Repair any marred or scratched surfaces with manufacturer's touch-up paint.

3.4 IDENTIFICATION

A. Provide engraved plaque on each VFD. Attach with mechanical fasteners.

3.5 FIELD QUALITY CONTROL

A. Manufacturer's Field Service: Provide services of a factory-authorized service representative to supervise the field assembly of components and installation of variable frequency drives, including electrical connections. Report results in writing.

1. Test and adjust controls and safeties.

2. Replace damaged and malfunctioning controls and equipment.

3.6 DEMONSTRATION

A. Engage a factory-authorized service representative to train Contracting Officer's Representative as specified below:

1. Train Contracting Officer's Representative on procedures and schedules related to startup and shutdown, troubleshooting, servicing and preventive maintenance.

2. Review data in the maintenance manuals.

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3. Schedule training with Contracting Officer's Representative, through Architect, with at least seven (7) days' advance notice.

END OF SECTION