Download emergency transfer cabinet

EMERGENCY TRANSFER CABINET.
A.) General.
1.) Emergency Transfer Cabinets are fully UL listed automatic transfer
switches. They are designed for any application where power to adequate safety
illumination; typical applications include public spaces such as hotel conference
areas, office buildings, or theatre and concert hall house lighting.
2.) Emergency Transfer Cabinets sense the normal supply voltage and
automatically transfer the load circuits to the emergency power feed(s) when a
phase failure is detected. When the supply is restored, transfer back to the normal
supply is also automatic.
B.) Mechanical.
1.) Cabinets shall be of sheet steel construction of no less than 16 gauge and shall
be wall mounted as follows:
a.) 2 way Emergency Transfer Cabinet: Four 0.31" (6.35mm) mounting holes
on 19" (482mm) horizontal and 21.875" (556mm) vertical centers.
b.) 4 way Emergency Transfer Cabinets: Four 0.44" (11.2mm) mounting
holes on 22.75" (578mm) horizontal and 39.87" (1012mm) vertical centers
c.) 6 and 8 way Emergency Transfer Cabinets: Four 0.44" (11.2mm)
mounting holes on 28.75" (730mm) horizontal and 45.87" (1165mm)
vertical centers.
2.) The cabinet shall be factory pre-wired and dressed. The contractor shall provide
and terminate normal, emergency, sense and load wiring on screw terminals or
lugs within the cabinet.
3.) Cable entry points shall be via the top, side and bottom panels of the cabinet.
Note: 4" (100mm) clearance shall be required on the right hand side panel for test
switch access.
4.) Normal feed, load terminals and single phase emergency feed terminals on the
power switches shall accept up to #8 AWG, 3 phase emergency feed terminals up
to #2/0 AWG wires. Sense terminals shall accept up to #14 AWG wires. All
terminations and internal wiring shall be accessible via a hinged latched door.
5.) Emergency Transfer Cabinets shall be convection cooled and shall maintain the
temperature of all components within the ambient temperature range defined in the
Environmental Specification.
6.) Cooling fans shall not be required.
7.) The cabinet shall be finished in powder coat semi gloss light grey paint.
C.) Standards.
1.) The emergency Transfer Cabinet shall be UL listed and evaluated to UL1008
standard for safety, and shall comply with the requirements of NEC Articles 230-83,
700 and 701.
D.) Electrical.
1.) The Emergency Transfer Cabinets shall comprise voltage sensing circuitry and
transfer switches to automatically transfer load circuits from the normal to the
emergency power feed(s) when the normal supply fails.
2.) The Emergency Transfer Cabinets shall be designed for use with 120/208 volt
3Ph 4W dimmer cabinets or building services and shall be available in the following
configurations:
a.) 2, 4, 6 and 8 (20A) load circuits each with an individual single-phase
emergency power feed.
b.) 2, 4, 6, and 8 (20A) load circuits with a single 120/208 volt 3Ph 4W
emergency power feed.
3.) The 3 phase emergency power feed shall have a maximum rating of 40A per
phase for the 4 and 6 way cabinets, 60A for the 8 way cabinet.
4.) Emergency Transfer Cabinets for 3 phase emergency power feeds shall have a
20A magnetic branch breaker per load circuits.
5.) Breakers shall be rated for a minimum of 10,000A interrupting capacity.
6.) Voltage sensing relays shall cause automatic transfer when the voltage of one
or more phases of the normal feed drops to 55% (i.e. 65 volts) or below.
7.) The transfer relays shall have both mechanical and electrical interlocks for
safety.
8.) On restoration of the normal supply, load circuits shall be transferred from the
emergency feed(s) to the normal supply automatically.
9.) An integral test switch shall be provided to simulate normal power source failure
for periodic verification of system operation. Access inside the cabinet for test
purposes shall not be necessary.
E.) Documentation.
1.) System riser and connection drawings shall be supplied as specified. Installation
instructions shall be supplied with each Emergency Transfer Cabinet.
F.) Environmental Specification.
1.) For Emergency Transfer Cabinets and associated equipment, the following
recommendations shall apply:
a.) Ambient temperature extremes: 32-104º Fahrenheit (0-40º C)
b.) Relative humidity: 10-90% non-condensing
c.) General conditions use only.
d.) Office level cleanliness - Interior