quest
Asset Protection and IAQ Solutions
quest
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Quest
DRY
150 Installation, Operation and Maintenance Instructions
www.thermastor.com
7.8 Defrost Thermostat
The defrost thermostat is attached to the refrigerant suction tube between the accumulator and the
compressor. It will automatically shut the compressor off if the low side refrigerant temperature drops due
to excessive frost formation on the evaporator coil. The impeller fan will continue to run, causing air to flow
through the evaporator coil and melt the ice. When the ice has melted, the evaporator temperature will rise
and the thermostat will restart the compressor.
7.9 Electric Ventilation Damper
The electric ventilation damper is controlled by the ventilation timer. The damper will open when the
ventilation timer is activated to allow fresh air into the structure through the 6” diameter fresh air inlet duct.
The electric ventilation damper will remain closed when the ventilation timer is not activated to prevent
over-ventilating the structure when the unit is dehumidifying or recirculating the indoor air.
The electric ventilation timer operates on 24 Vac from the control circuit.
DO NOT
connect high voltage to
the damper motor or damage to the motor may result.
DO NOT
force the blade of the damper by hand or
damage to the damper motor may result.
The damper opens in one direction only. The damper rotates very slowly, allow sufficient time for the damper
to cycle. The damper will take approximately 1 minute to cycle from closed to open or from open to closed.
If the electric ventilation damper fails to operate:
1. Check that the wiring is correct and that voltage is present at the damper motor.
2. Check for any obstruction inside the damper. If the electric ventilation damper fails to operate after
performing these checks, it must be replaced.
7.10 Condensate Pump Kit
An optional condensate pump kit is available from the factory for use with the Quest
DRY
150. Condensate
is automatically pumped to a remote location when the water level in the pump's reservoir rises to close the
float switch.
The pump also contains a safety float switch. The white leads from this switch extend from beneath the pump
cover. This switch should be installed in series with the field wire that connects the blue (#5) lead from the
Quest
DRY
150 to the blue (#5) lead on the control panel.
If the pump fails, this switch opens the compressor control circuit and stops water production before the
reservoir overflows. The Quest
DRY
150 will continue to ventilate or circulate air as normal, but will not
dehumidify until this switch closes.
FOR HVAC INSTALLER ONLY
