Unit shall be internally prewired with a [24] [120] [_____] volt control
circuit powered by an internal transformer. Terminal blocks shall be
provided for power wiring and external control wiring. Unit shall have
cutoffs for [high] [high and low] pressure, [and] low oil pressure for
compressors with positive displacement oil pumps, [supply fan failure],
[and safety interlocks on all service panels]. Head pressure controls
shall sustain unit operation with ambient temperature of [_____] degrees C
degrees F. Adjustable-cycle timers shall prevent short-cycling. Multiple
compressors shall be staged by means of a time delay. Unit shall be
internally protected by fuses or a circuit breaker in accordance with UL
1995. Low cost cooling shall be made possible by means of a control
circuit which will modulate dampers to provide 100 percent outside air
while locking out compressors.
2.7
REMOTE CONDENSER OR CONDENSING UNIT
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NOTE: Delete the sound requirements unless the unit
is located in a sound-sensitive area.
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Units with capacities less than 39.5 kW 135,000 Btuh shall produce a
maximum ARI sound rating of [_____] bels when rated in accordance with ARI
270. Units with capacities 39.5 kW 135,000 Btuh or greater shall produce a
maximum ARI sound rating of [_____] bels when rated in accordance with ARI
370. Each remote condenser coil shall be fitted with a manual isolation
valve and an access valve on the coil side. Saturated refrigerant
condensing temperature shall not exceed 49 degrees C 120 degrees F at 40
degrees C 95 degrees F ambient. Unit shall be provided with low ambient
condenser controls to ensure proper operation in an ambient temperature of
[_____] degrees C degrees F. Fan and cabinet construction shall be
provided as specified in paragraph "Unitary Equipment Components". Fan and
condenser motors shall have [open] [dripproof] [totally enclosed]
[explosion proof] enclosures.
2.7.1
Air-Cooled Condenser
Unit shall be rated in accordance with ARI 460 and conform to the
requirements of UL 1995. Unit shall be factory fabricated, tested,
packaged, and self-contained. Unit shall be complete with casing,
propeller or centrifugal type fans, heat rejection coils, connecting piping
and wiring, and all necessary appurtenances.
2.7.1.1
Connections
Interconnecting refrigeration piping, electrical power, and control wiring
between the condensing unit and the indoor unit shall be provided as
required and as indicated. Electrical and refrigeration piping terminal
connections between [condenser] [condensing unit] and evaporator units
shall be provided.
2.7.1.2
Head Pressure Control and Liquid Subcooling
Low ambient control for multi-circuited units serving more than one
evaporator coil shall provide independent condenser pressure controls for
each refrigerant circuit. Controls shall be set to produce a minimum of 95
degrees F saturated refrigerant condensing temperature. Unit shall be
provided with a liquid subcooling circuit which shall ensure proper liquid
SECTION 15700A
Page 24
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