Technical Information; Sequence Of Operation; Heating; Cooling - nvent SPECTRACOOL G52 Instruction Manual

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
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.

REMOTE ACCESS CONTROL (OPTIONAL)

See DIGITAL THERMOSTAT CONTROLLER (OPTIONAL) on page 12

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.

115V TO 10V OR 230V TO 10V TRANSFORMER (OPTIONAL)

This transformer powers the thermal display only.

115V TO 24V OR 230V TO 24V TRANSFORMER AND RELAY (OPTIONAL)

This transformer and relay are used to start/stop the unit thru a customer supplied, remote mounted door
switch.
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FOR HEATING (55-65 F RANGE):
•
•
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© 2022 nVent
Thermostat setpoint = 55 F
Heating turns on at 55 F
Heating turns off at 65 F
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