036-33073-001 Rev. A (0701)
6
Unitary Products Group
OPERATION
A room thermostat should be used to cycle the unit on and off
automatically as required to maintain the room temperature
at the set point of the thermostat. The air circulating fan will
cycle on and off with the compressor. If desired. the air circu-
lating fan can be run continuously. This requires a thermostat
with a separate fan selector switch on the thermostat sub-
base. Three wires are then required between the thermostat
and the unit. All single-phase units are equipped with hard
start kits. There is no need for off cycle timers.
The units have a lock out relay that will prevent the unit from
cycling on the low pressure cut out or the high pressure cut
out. If either of these safety devices open. the compressor
will not restart when the safety device resets. To restart the
compressor after a safety lock out. it will be necessary to
interrupt the power to the control circuit. This can be done at
the thermostat or at the disconnect.
MAINTENANCE
The air circulating fan motor has bearings that are factory
lubricated and sealed for long life. No further lubrication is
required. The compressor is part of a sealed refrigeration
system that does not require any additional lubrication.
The only maintenance required is to replace the air filter at
the return air intake to the cooling coil. when it becomes dirty
enough to restrict air circulation. It is recommended that the
return air filter be inspected every three months. Always
replace the filter with the same size of l-inch thick disposable
type of fiberglass filter.
TABLE 5: AIR FILTER APPLICATIONS.
MODEL
CH/CU
*Ol2A
*Ol8A
*O24A
*O30A
*O36A
*048A
*O60A
Nominal
Cooling
(Ton)
1
1.5
2
2.5
3*
4
5
Filters
CH -
Number
Used-
Size (in)
1-
14x20x1
l-
16x20x1
1-
20x20x1
1-
20x25x1
1-
20x25x1
1-
20x20x1
1-
20x20x1
1-
20x25x1
CU -
Number
Used-
Size (in)
1-
14x20x1
l-
16x20x1
1-
18x25x1
1-
18x25x1
1-
20x25x1
1-
16x25x1
1-
14x25x1
1-
18x25x1
1-
16x25x1
