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System Operation
The outdoor unit and indoor blower cycle on demand from
the room thermostat. When the thermostat blower switch is
in the
ON
position, the indoor blower operates continuously.
CAUTION
Danger of equipment damage. Do not bypass the dis-
charge thermostat.
High Pressure Switch
HS27 units are equipped with a high pressure switch that is
located in the discharge line of the compressor. The switch
(SPST, manual reset, normally closed) removes power
from the compressor when discharge pressure rises above
factory setting at 410 + 10 psi.
Low Pressure Switch
HS27 units are also equipped with a low pressure switch
that is located in the vapor line of the compressor. The
switch (SPST, auto−reset, normally closed) removes power
from the compressor when vapor line pressure drops be-
low factory setting at 25 + 5 psi.
Maintenance
WARNING
Electric shock hazard. Can cause inju-
ry or death. Before attempting to per-
form any service or maintenance, turn
the electrical power to unit OFF at dis-
connect switch(es). Unit may have
multiple power supplies.
Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each cooling
season, the system should be checked as follows:
1 − Clean and inspect the outdoor coil. The coil may be
flushed with a water hose. Ensure the power is turned
off before you clean the coil.
2 − The outdoor fan motor is prelubricated and sealed. No
further lubrication is needed.
3 − Visually inspect connecting lines and coils for evidence
of oil leaks.
4 − Check wiring for loose connections.
5 − Check for correct voltage at unit (unit operating).
6 − Check amp−draw outdoor fan motor.
Unit nameplate _________ Actual ____________ .
NOTE − If the owner complains of insufficient cooling,
the unit should be gauged and refrigerant charge
checked. Refer to section on refrigerant charging in
this instruction.
Indoor Coil
1 − Clean coil, if necessary.
2 − Check connecting lines and coils for evidence of oil leaks.
3 − Check the condensate line and clean it if necessary.
Indoor Unit
1 − Clean or change filters.
2 − Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
Refer to the unit information service manual for pressure
drop tables and procedure.
3 −
Belt Drive Blowers −
Check belt for wear and proper
tension.
4 − Check all wiring for loose connections
5 − Check for correct voltage at unit (blower operating).
6 − Check amp−draw on blower motor
Unit nameplate_________ Actual ____________.
Optional Accessories
The following optional accessories are available for use
with outdoor units:
Loss of Charge Kit
High Pressure Switch Kit
Compressor Monitor
Compressor Crankcase Heater
Hail Guards
Mounting Bases
Timed Off Control
Stand−off Kit
Sound Cover
Low Ambient Kit
