Carrier 50AH024 Installation, Start-Up And Service Instructions Manual page 25

Carrier
INSTALLATION
501
BA,BB,BCO
FIG. 22 - 50BA, BB, BC ELECTRICAL PANEL (208/220-3-60)
WATER-COOLED UNITS
The water-cooled condensing unit section is completely
wired at the factory. Field power connections are
made to starter terminals in control box through a pan¬
el which can be mounted either in front or back of the
unit. A terminal block provides connections for cool¬
ing tower controls. Compressors are protected by
magnetic overload relays which can be manually reset
by means of reset buttons on control box cover. High
and low pressurestats and an "off-fan-auto" selector
switch are included. For continuous fan operation
turn selector switch to "fan". For cycling of fan with
compressors turn switch to "auto".
Field wiring must be run to the terminals on the fan
starter, and compressor contactors.
The thermostats are not supplied by Carrier. See
wiring diagrams for field wiring.
CONDENSER LESS UNITS
The wiring on the condenserless units is the same as
for the water-cooled units. Included in the condens
erless units are compressor crankcase heaters
which are wired at the factory. The crankcase
heaters reduce liquid slugging in the compressor ai
excessive absorption of oil by the refrigerant, thus
replacing the need for liquid line solenoid valves.
Crankcase heaters are energized when the compres
sors are "off", by a normally closed contact on the
contactor. The heaters are rated for 100 watts,
230 voh, single phase, 60 cycle. Two condenser
fan relays S.P.S.T. (Normally Open) are included
with the base unit. These are field wired and
installed. See wiring diagrams.
The 440/550 volt units are supplied with a trans¬
former to supply 220 volt control voltage for the
base unit, and air cooled condenser control cir¬
cuit.
A terminal block is supplied in the control box for
ease of wiring of thermostat and air cooled con¬
denser relays.
The thermostats are not supplied by Carrier.
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