8
Installation and Operations Manual
Service Information
All
units are designed for maximum durability, reliability and
simplicity.
comes to you ready for operation, fully charged and
with all controls preset at the factory. The following information is
provided as an aid in the event that service is required.
Maintenance
The evaporator section of a
system should be checked at
least once for proper defrosting because the amount and pattern
of frosting can vary greatly. The frost build-up is dependent on
the temperature of the room, the type of product being stored,
how often new product is brought into the room and percentage
of time the door to the room is open. It may be necessary to
periodically change the number of defrost cycles or adjust the
duration of defrost.
System Standard Maintenance Guidelines
After first year of operation and under normal usage, maintenance
should cover the following items at least once every six months:
1. Check and tighten ALL electrical connections.
2. Check all wiring and insulators.
3. Check contactors for proper operation and for worn
contact points.
4. Check all fan motors. Tighten motor mount bolts/ nuts
and tighten fan set screws.
5. Clean the condenser coil surface.
6. Check the operation of the control system. Make certain
all safety controls are operating properly.
7. Check that all defrost controls are functioning properly.
8. Clean the evaporator coil surface.
9. Clean the drain pan and check the drain pan and drain line
for proper drainage.
Refrigeration Sequence of Operation
1. Power is provided to the temperature control, compressor
contactor and cooler evaporator fans.
2. The temperature controller closes and energizes the
compressor contactor, starting the compressor,
evaporator and condenser fan(s).
3. When the system reaches the desired box temperature,
the temperature control will de-energize the compressor
contactor. Evaporator fans will continue to operate at
this point.
4. When the fixture temperature rises above the set point
and minimum off-time has elapsed, the temperature
control will close and re-energize the compressor contactor.
Electric Defrost Sequence of Operation
for Freezers
1. During normal operation, at the preset time intervals,
the temperature/defrost control will de-energize the
compressor contactor and evaporator fans and energize
the defrost heaters. These functions are controlled
through relays on the controller.
2. When the coil has defrosted fully and has reached the
preset coil temperature (as sensed by the coil
temperature sensor) the defrost heater de-energizes
and the fan delay and drip sequences begin.
3. The temperature/defrost control energizes the
compressor contactor, starting the compressor and
condenser fan(s).
4. Freezer evaporator fans will be energized by the
temperature/defrost control when the coil temperature
reaches 35°F or fan delay time has elapsed.
Medium and Large Cabinet Freezers
2.
Fr
eez
ers
