This master should be used by designers working on Port of Portland construction projects and by designers working for PDX tenants (“Tenants”). Usage notes highlight a few specific editing choices, however the entire section should be evaluated and edited to fit specific project needs.

SECTION 263600 - TRANSFER SWITCHES

PART 1 - GENERAL

1.1DESCRIPTION

  1. This section describes transfer switches rated 600V and less, including the following:
  2. Automatic transfer switches.
  3. Nonautomatic transfer switches.

1.2REFERENCES

  1. NEMA: National Electrical Manufacturers Association
  2. NETA: International Electrical Testing Association
  3. UL: Underwriters Laboratories
  4. UL 508: Industrial Control Equipment

1.3SUBMITTALS

  1. Product Data: Submit for each type of product indicated. Include rated capacities, weights, operating characteristics, furnished specialties, and accessories.
  2. Shop Drawings: Dimensioned plans, elevations, sections, and details showing minimum clearances, conductor entry provisions, gutter space, installed features and devices, and material lists for each switch specified.
  3. Closeout Submittals: Provide operation and maintenance data.

PART 2 - PRODUCTS

2.1AUTOMATIC TRANSFER SWITCH

  1. General:
  2. The transfer switch, complete with all timers, relays, and accessories, shall be UL-listed under Standard UL1008 and approved for use on emergency systems. The UL listing shall include the specific amperage ratings that are called for on the drawings.
  3. Contain a short circuit withstand capability and closing ratings when coordinated with circuit breakers in excess of the UL minimum requirement of 42,000 RMS amperes symmetrical.
  4. Completely wired, assembled, and tested by the manufacturer at the factory to ensure compatibility and to completely test the assembly.
  5. Provide the transfer switch as shown on the drawings with full load current rating of amperes at 277/480V, 3phase, 4wire, 60 Hertz AC normal and emergency.
  6. Capable of switching all classes of load and rated for continuous duty when installed in nonventilated enclosures.
  7. Provide exercise timer, automatically actuated, to permit weekly programming of engine generator test runs under load. If the emergency source should fail during the exercise period, and if normal power is available, the switch shall immediately restore to normal.
  8. Auxiliary contacts shall be provided to monitor the status of the ATS.
  9. Microprocessor controlled with front accessible HMI interface.
  10. Listed and rated as service equipment.
  11. Transfer Switch Construction:
  12. Inherent 4pole switched neutral type with all four poles on a common shaft.
  13. Double-throw actuated by two electrical operators momentarily energized and connected to the transfer mechanism by a simple overcenter type linkage with a minimum transfer time of 400 MSEC. Provide an adjustable pneumatic timer, 0 to 60 seconds, on delayed equipment transfer switch.
  14. Capable of transferring successfully in either direction with 70percent of rated voltage applied to the switch terminals.
  15. The normal and emergency contacts shall be positively interlocked mechanically and electrically to prevent simultaneous closing. Main contacts shall be mechanically locked in position in both the normal and emergency positions without the use of hooks, latches, magnets, or springs and shall be silver tungsten alloy protected by arcing contacts with magnetic blowouts on each pole.
  16. Equipped with safe manual operators that are designed to prevent injury to the operating personnel if the electrical operation should suddenly become energized during manual transfer. The manual operator shall provide the same contact transfer speed as the electrical operator in order to prevent a flashover caused by switching the main contacts too slowly.
  17. Include pilot lights on the enclosure door to indicate the switch closed on normal or emergency, and four auxiliary contacts on the main shaft, two closed on normal, and two closed on emergency. Load test switch to simulate normal power failure. All relays, timers, control wiring, and accessories shall be front accessible.
  18. Voltage Sensing: Provide the automatic transfer switch with voltage sensing relays for each phase. Connection of these sensing relays shall be made to the normal power input terminals of the transfer switch. Voltage range shall be field adjustable.
  19. Include a two position selector switch to select either automatic or manual transfer operation with pushbuttons to transfer to emergency and re-transfer to normal.
  20. Install each automatic transfer switch in an enclosure with locking hinged door conforming to NEMA ICS and complying with the requirements of UL 508.
  21. Main terminals requiring field wiring connections shall be suitable for copper wiring.
  22. Automatic transfer switches shall be suitable for satisfactory performance when installed for operation at 200-feet altitude, 40°C high and minus 20°C low ambient temperature, 90 percent relative humidity.
  23. Color of the finish coat of paint shall be manufacturer’s standard.
  24. Acceptable manufacturer is Russelectric “RMTD” type, or pre-bid approved equal.

2.2NONAUTOMATIC TRANSFER SWITCHES

  1. Operation: Electrically actuated by push buttons designated “Normal Source” and “Alternate Source.” Switch shall be capable of transferring load in either direction with either or both sources energized.
  2. Double-Throw Switching Arrangement: Incapable of pauses or intermediate position stops during switching sequence.
  3. Nonautomatic Transfer-Switch Accessories:
  4. Pilot Lights: Indicate source to which load is connected.
  5. Source-Available Indicating Lights: Supervise sources via transfer-switch normal- and alternate-source sensing circuits.
  6. Normal Power Supervision: Green light with nameplate engraved “Normal Source Available.”
  7. Emergency Power Supervision: Red light with nameplate engraved “Alternate Source Available.”

2.3UNASSIGNED AUXILIARY CONTACTS

  1. One set of normally closed contacts for each switch position, rated 10A at 240-V ac.

PART 3 - EXECUTION

3.1INSTALLATION

  1. Neatly lace and secure the conductors of the feeder circuits individually at maximum 2foot intervals. The cable lugs shall not support the weight of the cables.
  2. Identify components according to Section 260533, Identification for Electrical Systems.
  3. Automatic Transfer Switch: Install automatic transfer switch as shown on the drawings and according to the manufacturer’s recommendations.
  4. Concrete Pads: Provide minimum 3inch-thick concrete housekeeping pads under all freestanding pieces of switchgear. Extend pads a minimum of 2inches beyond the edges of the equipment.

3.2STARTUP, TESTING, AND TRAINING

  1. Comply with NETA standards.
  2. Perform startup and testing of the equipment after installation has been completed.
  3. Testing:
  4. Set time delays and sensing control wiring for automatic start/stop operation and time delays between transfer switches.
  5. Fully test switch operation. Tests shall be witnessed by the Port.
  6. Upon completion of the onsite tests, a general inspection shall be made for any deficiency which may impair proper operation.

3.3ACCEPTANCE

  1. Final acceptance will not be granted by the Port until onsite tests have been successfully completed, all defects in material or operation have been corrected, and operating and maintenance data has been submitted along with all completed test reports.

END OF SECTION263600

10/10/2018 / TRANSFER SWITCHES
S:\MASTERS\DIV-26\263600MT.DOC / 263600-1