© 2011 Pentair Technical Products
89056287
- 6 -
TECHNICAL INFORMATION
Sequence of Operation
The air conditioner comes standard with two internally mounted thermostats. There are two modes of operation;
heating and cooling. During heating and cooling modes, the evaporator fan will be running.
Heating
When the enclosure temperature is below the heating thermostat setpoint, power is applied to the heaters.
When the enclosure temperature is 10 degrees above the setpoint, the heater is powered off.
Cooling
When the enclosure temperature is above the cooling thermostat setpoint, power is applied through the
thermostat. The compressor is then energized either directly or through a contactor if unit requires one. The
condenser impellers will start immediately if the unit is not equipped with an optional head pressure control
switch. If the unit is equipped with an optional head pressure control switch, the condenser impellers will
start once the refrigerant pressure reaches the setting of the switch. Component specific information is listed
below.
Operating the air conditioner below the minimum ambient temperature or above the maximum ambient
temperatures indicated on the nameplate voids all warranties. DO NOT set the enclosure thermostat to a
temperature lower than 70 F. Doing so can increase the likelihood of frost buildup on the evaporator coil.
The moisture that the enclosure air can contain is limited. If moisture flows from the drain tube continuously
this can only mean that ambient air is entering the enclosure. Be aware that frequent opening of the
enclosure’s door admits humid air that the air conditioner must then dehumidify.
Standard and Optional Component Operation
Thermostat
The G52 air conditioner uses our standard 10-1061-16 thermostat. The thermostat setpoint equals the
temperature that the air conditioner turns off. The thermostat has a 10 F differential from setpoint until it calls
for cooling or heating. An example of operation is shown below.
For cooling (75-100 F range):
•
Thermostat setpoint = 80 F
•
Cooling turns on at 90 F
•
Cooling turns off at 80 F
For heating (55-65 F range):
•
Thermostat setpoint = 55 F
•
Heating turns on at 55 F
•
Heating turns off at 65 F
NOTE: For testing purposes only, the thermostat stop screw may be removed (on units so
equipped) to allow settings below 70 F. After testing, replace the stop screw and verify that the
thermostat cannot be set below 70 F. Extended operation below 70 F can cause coil freeze ups
resulting in reduced load and/or unit damage.
Head Pressure Control
Unit is set at the factory, no adjustment necessary.
At a saturated condenser temperature of 85 F (95 psig), the condenser fans will power off. At a saturated
condenser temperature of 118 F (165 psig), the condenser fans will power on.
Contactor (115V 12000 BTU/Hr.. Units only)
The contactor on this model uses a 115V coil.
