292424-XIM-A-0307
Unitary Products Group
15
CONDENSER FAN OPERATION
These condensing units are factory equipped with a fan
cycling switch to regulate system head pressure. When out-
door ambient conditions are cool, the head pressure of any
air conditioning system may drop too low for optimal perfor-
mance. These condensing units maximize system perfor-
mance in a variety of ambient conditions by incorporating a
fan cycling switch to maintain proper system head pressure.
On these condensing units, the condenser fans are powered
when compressor one is energized. Fan one will start imme-
diately upon a call for first stage cooling. However, fan two is
equipped with a fan cycling switch and will not start until the
system head pressure reaches 320 psig. Condenser fan two
will operate until the system head pressure drops below 180
psig where the fan cycling switch will shut the fan down. The
unit will continue to operate condenser fan one until the sys-
tem head pressure reaches 320 psig at which time condenser
fan two will restart.
SAFETY FEATURES
1.
The compressor is protected against over current and
excessive temperature as described in the Sequence of
Operation.
2.
The compressor is equipped with a crankcase heater to
discourage refrigerant migration into the compressor
sump during the OFF cycle.
3.
The condenser fan motors have auto-reset internal pro-
tection.
4.
The secondary of every transformer is grounded.
5.
Every unit is protected by high and low-pressure con-
trols.
SECURE OWNER'S APPROVAL
When the system is functioning properly, secure the owner's
approval. Show him the location of all disconnect switches
and the thermostat. Teach him how to start and stop the unit
and how to adjust temperature settings within the limitations
of the system.
MAINTENANCE
CLEANING CONDENSER SURFACE
Dirt should not be allowed to accumulate on the condenser
coils or other parts in the condenser air circuit. Clean as often
as necessary with a brush, vacuum cleaner attachment or
other suitable means.
LUBRICATION
The fan motors for these condensing units are equipped with
factory lubricated and sealed ball bearings. They do not
require any maintenance.
COMPRESSOR REPLACEMENT
Contact the local UPG Distribution Center for compressor or
parts.
