SECTION 16621 AUTOMATIC TRANSFER EQUIPMENT

This spec was part of the Des Plaines, IL River WRF project that bid Feb 26, 2015.


SECTION 16621 AUTOMATIC TRANSFER EQUIPMENT


PART 1 GENERAL

1.1 RELATED REQUIREMENTS

A. Applicable requirements of Division 0 and Division 1 shall govern work in this Section.

1.2 DESCRIPTION

A. Provide a factory assembled, metal enclosed, automatic transfer switch for distribution and control of power from normal power supply or from output of a standby engine/generator upon failure of normal power supply to outgoing feeder terminals and automatic retransfer back to normal power supply upon resumption of normal service.

1.3 QUALITY ASSURANCE

A. Equipment shall comply with the requirements of the following Regulatory Agencies:
1. U.S. Environmental Protection Agency (EPA). Design criteria for Mechanical, Electrical, and Fluid System and Component Reliability.
2. National Fire Protection Association (NFPA)
3. Underwriters' Laboratories, Inc. (UL)
4. Local Codes and Ordinances
5. American National Standards Institute (ANSI)
6. National Electrical Manufacturers Association  (NEMA).  Standard ICS.
7. National Electrical Code (N.E.C.)
8. Occupational Safety and Health Administration (O.S.H.A.)

B. Perform the following production tests on the completed transfer switch:
1. Operation of individual components.
2. Correct overall sequence of operation.
3. Transfer time.
4. Voltage.
5. Time delay settings.
6. Dielectric strength test per NEMA Standard ICS 1-109.05.

C. A prototype of the switch shall have been subjected to and have passed the following tests by a certified independent testing laboratory.
1. Overload and endurance at 480 VAC per Table 21.2 and 23.2 of UL 1008 when enclosed per Table 1.6.

D. Provide with fully rated neutral bar.

E. The switch shall have passed tests per paragraph 25 of UL 1008 to withstand current @ 480 VAC and X/R ratio of 6.6 or less using MCB upstream of the ATS.

F. The entire transfer switch and relay plate assembly should be capable of withstanding a 2500 volt crest transient per IEEE standard 472-1974.  The transient voltage test shall be conducted across the normal source terminals, the emergency source terminals, and between opposite normal and emergency source terminals. A certified laboratory test report from an independent testing laboratory shall be furnished to verify conformance.

1.4 SUBMITTALS

A. Shop drawings shall indicate transfer switch, control panel and enclosure dimensions, control arrangements, and singleline diagrams in accordance with ANSI Y 32.2 indicating connections and controls.

B. Submit operation and maintenance manuals under provisions of Section 01730.
1. Submit manufacturer's written recommendations for storage and protection, installation instructions, and field test requirements.
2. Submit manufacturer's instructions for start-up, performing cleaning, operating, and maintaining transfer switch systems.

C. Submit certificates of proper installation and operator training (by manufacturer’s representative) under provisions of Section 01445.


PART 2 PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS

A. Eaton Series CBV9MG.

B. Engineer-approved equal.

2.2 TRANSFER SWITCH RATINGS

A. 2500 Amp, 480Y/277 volt, 3 phase, 4 wire.

B. Switch shall be 4 pole (3 pole with switched neutral).

C. Minimum Short Circuit Rating: 65,000 rms sym amps.

D. NEMA 1 enclosure, bypass isolation. The power circuit breaker and (3) power case switches shall all be draw-out construction.

E. Deadfront.

F. Service-entrance rated, with ground fault protection system.

G. Overall enclosure width not to exceed 64 inch. Enclosure depth shall not exceed 60 inches.

2.3 EQUIPMENT SWITCH CONSTRUCTION

A. Transfer switch is to be mechanically held, electrically operated by a single solenoid or motor mechanism momentarily energized from the source to which the load is being transferred.

B. The switch shall be rated for continuous duty and shall be mechanically interlocked to ensure only one of two possible positions, normal or emergency.

C. Load carrying parts shall have full 600-volt insulation.

D. The transfer switch shall consist of a power transfer module and a control module separately mounted.  Control module shall be mounted on the inside surface of the enclosure door to facilitate safe adjustment and service.  Harnessing between transfer module and control module shall have built-in disconnect.

E. The automatic transfer switch shall be suitable for use in emergency systems, listed by Underwriter's Laboratories under Standard 1008 for total system transfer.

F. The transfer switch shall be capable of switching all classes of load and shall be rated for continuous duty when installed in a non-ventilated enclosure constructed in accordance with Underwriters' Laboratories, Inc. Standard UL-508.

G. Each NORMAL breaker and EMERGENCY breaker shall be electrically operated and work as a pair in the transfer sequence.  Breakers shall be 100% rated power circuit breakers with integral solid-state trip units including LSIG functions.  All settings shall be adjustable. The breakers shall comply with UL 1066.

H. The transfer switches shall be equipped with a manual operator per paragraph 14 of UL standard 1008 that is designed to prevent injury to the operating personnel if the electrical operator should suddenly become energized during manual transfer. The manual operator shall provide the same contact-to-contact transfer speed as the electric operator                to prevent a flashover from switching the main contacts slowly. The manual operator shall be designed to operate without opening the enclosure door. The switch assembly shall be designed such that manual operation will not put the person standing in front of it at risk of Arc Flash. A mechanical visual indicator for the switch position shall be provided.

I. All relay, timers, control wiring and accessories shall be front accessible. Test switch and pilot lights shall be on front of cabinet door. The voltage sensing relays and all adjustable times shall be capable of being adjusted while energized, through calibrated dials.  All control wire terminals shall be ring or locking spade terminals.

J. All wiring shall be identified by tubular sleeve-type markers.

K. ARC FLASH WARNING LABELS
1. All transfer switches shall include a warning label indicating the risk of arc flash. The warning label shall comply with N.E.C. article 110.16 and O.S.H.A. 29.

2.4 ACCESSORIES

A. The control panel shall meet or exceed the voltage surge withstand capacity in accordance with IEEE Std. 472-1974 and impulse voltage withstand test in accordance with NEMA Std. ICS 1-109 and shall be supplied with the following accessories:
1. Engine starting contacts, gold plated for low voltage DC service. Contacts to close on failure of normal source to initiate engine starting.
2. Auxiliary contact to open when normal fails.
3. Independent voltage and frequency sensing network to prevent transfer to emergency until generator voltage is 90% of nominal and generator frequency is 95% of nominal.
4. Time delay on engine starting .5 to 3 second adjustable time delay to ignore momentary outages, factory set at 3 seconds.
5. Adjustable time delay on retransfer to normal (motor driven type - 0 to 30 minutes) fixed 5 minute unloaded running time for cool-down of stand-by plant after retransfer to normal.
6. Solid State Close Differential Relay protection on normal.  Three Close Differential Sensing Relays factory set for 90% pickup, 80% dropout.  Relays are adjustable in the field.
7. Test switch momentary type to be mounted on cabinet. Provides for testing operation of emergency plant and transfer switch (simulates normal power failure).
8. Green Pilot Light for indicating switch in normal position.
9. Red Pilot Light for indicating switch in emergency position.
10. Auxiliary Contact on main shaft (closed on normal).
11. Auxiliary Contact on main shaft (closed on emergency).
12. Assembly shall include an in-phase monitor/controller. The controller shall be bi-directional, operating independent of line voltage to assure transfer between live sources in either direction within a 20 degree phase angle difference (to protect system from abnormal motor inrush currents).
13. Controller shall be microprocessor-based and shall include IEEE-25 Sync Check function for operation of the closed transition feature. In-phase closed transition shall overlap the NORMAL and EMERGENCY sources for 100mS or less.
14. Controller Display: The controller shall also include a display that provides the following: the connected source and load voltages, the condition status: under- voltage, under-frequency; historical data, availability status of the NORMAL source, availability status of the EMERGENCY source, connection status of the NORMAL source, connection status of the EMERGENCY source, and mode status (auto, test, program).
15. Controller selector switches: controller shall include a selector switch for AUTO, LOCK-OUT, or MANUAL.  The controller shall also include a selector switch for AUTO RETRANSFER or MANUAL RETRANSFER.
16. A power meter on the load side of the transfer switch bus. This power meter shall measure per phase voltage and current, apparent power, real power, reactive power, power factor, and total harmonic distortion. Meter shall include trend logging, load profile logs, and event logs.  Power meter shall include MODBUS TCP/IP commication.

PART 3 EXECUTION

3.1 INSPECTION

A. Examine area to receive transfer switch to assure adequate clearance for transfer switch installation.

B. Start work only after unsatisfactory conditions are corrected.

3.2 INSTALLATION

A. Install transfer switch in accordance with manufacturer's written instructions and NEC.

B. Contractor shall provide control wiring as required between transfer switch starting contacts and generator. Starting contacts for multiple transfer switches served from the same generator shall be wired in parallel. Control wiring shall be in conduit.

C. Extend the existing housekeeping pad as required to support the new transfer switch assembly.

3.3 FIELD QUALITY CONTROL

A. Field Test Prior to Start-up.

B. Megger check of phase-to-phase and phase-to-ground insulation levels.

C. Continuity.

D. Do not megger check solid state equipment.

E. Perform tests according to transfer switch manufacturer's instructions.

3.4 ADJUSTMENTS AND CLEANING

A. Check adjustment of mechanism for free mechanical movement.

B. Tighten connections and mechanical fasteners.

C. Touch up scratched or marred surfaces to match original finish.

3.5 TRANSFER SWITCH START-UP

A. Retain services of transfer switch manufacturer's factory trained technician to perform following services:

B. After engine/generator load bank test and after engine/generator set is electrically connected to automatic transfer switch, provide comprehensive demonstration of system maintenance and operation to OWNER or OWNER'S maintenance personnel.

C. Include minimum of six simulated power failures.

3.6 PRODUCT DELIVERY, STORAGE AND HANDLING

A. Do not store indoor type equipment exposed to weather.

B. Protect system equipment from work of other trades.




END OF SECTION