Download SECTION 16409

SECTION 16409
POWER DISTRIBUTION UNITS
409.01
A.
Manufacturer
Power Distribution Units shall be manufactured by Emergency Power
Engineering (EPE), AAA Power System Company or Computer Power
Systems (CPS). The manufacturer shall have at least a 4 year history
with PDU’s.
409.02
A.
Description
The basic components of the PDU shall consist of an input power
cable with input junction box, main input circuit breaker, cabinet, multishield isolation transformer, internal wiring, single point ground, output
42 pole panelboard(s) with secondary circuit breaker protection,
system status panel, conduit landing bracket for output cables and any
optional features.
409.03
A.
Construction
The PDU shall be U.L. Listed under standard 478 for data processing
equipment. All components shall be U.L. Listed.
The input power cable shall be liquid tight flexible conduit, conductors
shall be sized to carry 125% of full load capacity of the PDU. The
ground conductor shall be the same size as the phase conductors.
The input junction box shall have a terminal strip to connect the
incoming conductors to the PDU input power conductors. The junction
box shall be sized in accordance to the NEC.
The PDU shall be equipped with a main input circuit breaker with a low
voltage shunt trip coil. The main C.B. shall be rated for 125% of full
load, molded case construction, and thermal magnetic type. The rating
shall be 22,000 AIC minimum, unless a higher rating is specified.
The cabinet shall consist of a metal frame to solidly support all
components, wiring, and metal covers. Internal sheet metal, not
welded to the frame shall be plated with Gold Zinc Wash to ensure
RFE, EMI susceptibility is reduced. Removable side, front and rear
panels shall be provided for access to components. Any mesh or
screening used for cooling shall have holes no larger than 3/32 to
prevent objects from entering the enclosure.
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SECTION 16409
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The transformer shall have electrostatic multi-shields, bc convection
cooled, 3 phase delta-wye; with copper windings and adjustable
taps: 2-2 ½% above and 4-2 ½% below. Efficiency - 96% noise
rejection - common mode of 120 db and normal mode of 60 db.
Internal wiring shall be multi-stranded conductors, with terminations
clearly labeled. Secondary and Primary power wiring shall not pass
through the same access holes in the transformer shield. When in
close proximity, secondary and primary wiring shall cross at 90 to
reduce noise.
A single point copper ground bus shall be provided. Minimum size is
¼” thick X 1" wide. The bus should be silver plated to provide best
connections. The following shall be grounded to the bus: transformer
neutral, transformer core, primary and secondary shields, frame,
equipment grounding conductors from the branch circuits, system
monitoring electronics, all input and output conduits through the
conduit landing plates.
One or more output panelboards with secondary circuit breaker
protection shall be provided. The PDU shall be provided with plug-in
circuit breakers, Square “D” or equivalent. Each panelboard shall have
42 pole positions and have separate ground and neutral bus for each
panel.
The system status panel shall have the following features: output
voltage, current (3 phases), KVA, and % load. Alarm shall include
over/under voltage, transformer over temperature shutdown, and any
other alarms that may be specified. Functions shall include EPO,
alarm sheet, audible alarm, and audible silence.
Remote EPO interface shall be provided. The terminal connection
point shall be clearly marked.
409.04
A.
Electrical Characteristics
Input voltage: 480, or 208 VAC as specified, 3 ph, 3 wire plus ground/
Frequency: 60HZ
Output voltage: 120/208 VAC, 3 ph, 4 wire, plus ground.
Main Input Circuit Breaker: Rated 125% of full load.
B.
Environmental Characteristics Temperature: 10 to 40C
Relative Humidity: 10% - 70%
Acoustic noise level: 60 db at 5 ft. (A scale)
***END OF SECTION 16409***
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