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3-Way Manual Transfer Switch Standard Specs (PDF)
3-Way Manual Transfer Switch Standard Spec (DOC)
(revised as of 04/01/20)
SECTION 1 – GENERAL REQUIREMENTS
A. Contractor shall furnish, deliver, install and test the 3-way manual transfer switches as specified herein and in accordance with the drawings.
1.01 Scope:
1.02 Quality Assurance:
A. 3-way manual transfer assembly switch shall be UL listed per the UL 1008 standard.
B. 3-way manual transfer switch shall be special seismic certified by OSHPD exclusively on the basis of approved shake table testing, and also certified to IBC 2015. Minimum IBC 2015 design parameters shall be as follows: Ip = 1.5, SDS = 2.0g, z/h = 1.0.
C. 3-way manual transfer switch manufacturer shall provide a complete factory assembled, wired and tested 3-way manual transfer switch
D. 3-way manual transfer switch shall be factory Hi-pot tested for a period of not less than 60 seconds.
E. 3-way manual transfer switch installation shall meet all applicable NEC standards.
1. 2017 NEC 700.3 (F) compliant when used in conjunction with an ATS and appropriate auxiliary equipment.
1.03 Submittals:
A. Contractor shall submit manufacturer’s drawings and data of 3-way manual transfer switches for Engineer’s approval prior to start of fabrication. Drawings and data shall include, as a minimum, dimensioned general arrangement drawings and wiring diagrams, UL listing information including UL file or control number, short circuit rating or withstand rating, component data, mounting provisions, conduit entry locations and installation instructions.
B. Upon installation of 3-way manual transfer switches Contractor shall submit manufacturer’s Operating & Maintenance Manual which shall include as a minimum:
1. Certified as-built General Arrangement drawings and Wiring Diagram.
2. Materials / Component List including part numbers.
3. Maintenance and service requirements.
4. Certificate of Compliance and hi-pot test data.
1.04 Warranty:
A. 3-way manual transfer switches shall be covered by manufacturer’s warranty for a minimum period of (1) one year after shipment from manufacturer.
SECTION 2 – PRODUCTS
2.01 General:
A. All equipment shall be new.
B. 3-way manual transfer switch manufacturer must have produced and sold UL 1008 Listed manual transfer switches as a standard product for a minimum of (3) years.
C. 3-way manual transfer switches shall be molded case circuit breaker type; knife switch or fused switches are not acceptable.
D. Contractor shall be responsible for the equipment until it has been installed and is finally inspected, tested and accepted in accordance with the requirements of this Specification.
E. 3- way manual transfer switches shall be TripleSwitch as manufactured by ESL Power Systems, Inc. or equal as approved by the Engineer.
2.02 3-way Manual Transfer Switches:
A. 3-way manual transfer switch shall consist of (2) mechanically-interlocked molded case circuit breakers, and (1) independent load bank breaker with a shunt trip (shunt trip voltage to be per the drawings), male cam-style inlet connectors, female cam-style outlet connectors, power distribution blocks and grounding terminals, all housed within a padlockable enclosure.
B. WALL-MOUNT ENCLOSURES
3-way manual transfer switch enclosure shall be Type 3R, constructed of continuous seam-welded, powder coated galvanneal steel. The main access shall be through an interlocked, hinged door that extends the full height of the enclosure. Access for both portable generator cables with female cam-style plugs and for load bank cables with male cam-style plugs shall be via a drawn flange cable entry openings in the bottom of enclosure. A hinged flap door shall be provided to cover the cable openings when cables are not connected; the hinged flap door shall allow cable entry only after the main access door has been opened. Enclosure shall be powder coated after fabrication; color shall be wrinkle gray RAL 7035.
PAD-MOUNT ENCLOSURES
3-way manual transfer switch enclosure shall be Type 3R, constructed of continuous seam-welded, powder coated galvanneal steel. The main access shall be through a hinged door that extends the full height of the enclosure. Access for both portable generator cables with female cam-style plugs and for load bank cables with male cam-style plugs shall be via a hinged lower flap door. Hinged flap door shall be provided to cover the cable openings when cables are not connected; the hinged flap door shall allow cable entry only after the main access door has been opened. Enclosure shall be powder coated after fabrication; color shall be wrinkle gray RAL 7035.
C. Cam-style male connectors (inlets) and cam-style female connectors (outlets) shall be UL Listed single-pole separable type and rated 400 amps at 600VAC. All cam-style connectors shall be color coded. Cam-style connectors shall be provided for each phase and for ground, and shall also be provided for neutral. Each of the phase cam-style connectors and the neutral cam-style connectors within the enclosure shall be factory-wired to a molded case circuit breaker. The ground cam-style male connectors shall be bonded to the enclosure, and a ground lug shall be provided for connection of the facility ground conductor. None of the cam-style connectors shall be accessible unless all (3) molded case circuit breakers are in the “OFF” position and the main access door is open.
D. A power distribution block shall be provided for load-side field wiring. The power distribution block shall be factory wired to the molded case circuit breakers.
E. Molded case circuit breakers shall be UL Listed 3-pole and the short circuit interrupt rating shall be a minimum of 35kAIC at 480VAC (wall mount units) or 50kAIC at 480VAC (pad mount units). Trip rating of the molded case circuit breakers shall be as shown on the drawings. One molded case circuit breaker shall control the connection between the permanent generator and the automatic transfer switch. A second circuit breaker shall control the connection between the permanent generator and the load bank female cam-style connectors. A third circuit breaker shall control the connection between the portable generator (via male cam-style connectors) and the automatic transfer switch. All (3) molded case circuit breakers shall include UL Listed door-mounted operating mechanisms, preventing the opening of the main access door unless all (3) breakers are in the “OFF” position. All (3) molded case circuit breakers shall be mounted behind a deadfront panel. The load-side of the molded case circuit breakers shall not be energizable unless the main access door is closed and one of the molded case circuit breakers is in the “ON” position. The (2) molded case circuit breakers controlling the connections between the permanent generator and the automatic transfer switch, and the connection between the portable generator and automatic transfer switch shall be safety interlocked by mechanical means to ensure that only one of these breakers can be closed at any given time.
F. An auxiliary contact shall be provided in the circuit breaker controlling the connection from the Permanent Generator to the ATS and shall be factory wired to terminal blocks within the enclosure. The auxiliary contact is provided in compliance with NEC 2017 700.3 (F)(5) which requires a means to activate an annunciator circuit.
SECTION 3 – EXECUTION
3.01 Installation:
A. Prior to installation of 3-way manual transfer switches, Contractor shall examine the areas and conditions under which the 3-way manual transfer switch is to be installed and notify the Engineer in writing if unsatisfactory conditions exist.
B. 3-way manual transfer switch shall be installed as shown on the drawings and per the manufacturer’s written instructions. In addition, the installation shall meet the requirements of local codes, the National Electrical Code and National Electrical Contractors Association’s “Standard of Installation”.
C. Conduit entry into the 3-way manual transfer switch shall be by Contractor; Contractor shall furnish and install listed watertight conduit hubs, as manufactured by MYERS or T&B, for each conduit entry on the 3-way manual transfer switch. The incoming hub size shall match the conduit size for feeders and ground as shown on the drawings. The outgoing hub size shall match the conduit size for loads and ground as shown on the drawings. Hubs shall be properly installed and tightened to maintain Type 3R integrity of the 3-way manual transfer switch enclosure.
D. Contractor shall terminate feeder conductors, load conductors and ground per the manufacturer’s instructions. All field wiring terminations shall be torqued as required per the instructions on the 3-way manual transfer switch’s power distribution blocks, circuit breakers & ground lugs.
3.02 Field Testing:
A. Prior to energizing 3-way manual transfer switch, the Contractor shall perform the following checks and tests as a minimum:
1. Verify mounting and connections are complete and secure.
2. Verify internal components and wiring are secure.
3. Perform continuity check of all circuits.
4.Perform 1,000 VDC megger test on feeder and load cables. Prior to testing, all auxiliary circuits must be turned OFF and all fuses, microswitches and shunt trip circuits must be disconnected. It is required to take out the rating plug of any electronic trip circuit breakers while performing a megger (insulation) test.
5. Verify deadfront is secure.
6. With the 3-way manual transfer switch deadfront in place and the main access
door closed and properly latched, actuate all (3) Operator Mechanisms; verify:
A).With the breaker controlling the connection between the permanent generator and the automatic transfer switch (ATS) in the “ON” position, the breaker controlling the connection between permanent generator and the load bank can be turned to the “ON” and “OFF” position and the breaker controlling the connection between the portable generator and the automatic transfer switch cannot be turned “ON.”
B) With the breaker controlling the connection between the permanent generator and the automatic transfer switch (ATS) in the “OFF” position, the other (2) breakers controlling the connection between the permanent generator and load bank can be turned “ON” or “OFF”, and the breaker controlling the connection between the portable generator and the automatic transfer switch can be turned “ON” and “OFF.”
C) With the breaker controlling the connection between the portable generator and the automatic transfer switch (ATS) in the “ON” position, the breaker controlling the connection between the permanent generator and the automatic transfer switch (ATS) cannot be turned “ON” and the breaker controlling the connection between the permanent generator and load bank can be turned “ON” and “OFF.”
7. Confirm operation of the 3-way manual transfer switch ground receptacle by attaching a plug to the 3-way manual transfer switch ground receptacle and then verify that the plug is grounded to the facility ground.
8. Once normal power has been applied, confirm operation of 3-way manual transfer switch by following directions on main access door.
