Manual
2100-369E
Page
14 of 18
IMPORTANT INSTALLER NOTE
For improved start-up performance, wash the indoor coil
with a dishwasher detergent.
CRANKCASE HEATERS
All units are provided with some form of compressor
crankcase heat.
All single and three phase models have an insertion well-
type heater located in the lower section of the compressor
housing. This is a self-regulating type heater that draws
only enough power to maintain the compressor at a safe
temperature.
Some form of crankcase heat is essential to prevent liquid
refrigerant from migrating to the compressor, causing oil
pump out on compressor start up and possible valve
failure due to compressing a liquid.
The decal in Figure 8 is affixed to all outdoor units
detailing start up procedure. This is very important.
Please read carefully.
SERVICE HINTS
1. Caution homeowner to maintain clean air filters at all
times. Also, not to needlessly close off supply and
return air registers. This reduces airflow through the
system, which shortens equipment service life as well
as increasing operating costs.
2. Check all power fuses or circuit breakers to be sure
they are the correct rating.
3. Periodic cleaning of the outdoor coil to permit full and
unrestricted airflow circulation is essential.
SEQUENCE OF OPERATION
Cooling—Circuit R-Y makes at thermostat pulling in
compressor contactor, starting the compressor and
outdoor motor. The G (indoor motor) circuit is
automatically completed on any call for cooling operation
or can be energized by manual fan switch on subbase for
constant air circulation. On all 230 volt units there is a
one-minute off delay on the blower motor. 460 volt
models do not have an off delay. On a call for heating,
circuit R-W1 make at the thermostat pulling in heat
contact for the strip heat and blower operation. On a call
for second stage heat, R-W2 makes bringing on second
heat contactor, if so equipped.
START UP
COMPRESSOR CONTROL MODULE
The compressor control module is optional on the models
covered by this manual. The compressor control is an
anti-short cycle/lockout timer with high and low pressure
switch monitoring and alarm relay output.
Adjustable Delay On Make And Break Timer
On initial power up or anytime power is interrupted to the
unit, the
delay on make
period begins, which will be 2
minutes plus 10% of the
delay on break
setting. When
the delay on make is complete and the high pressure
switch (and low pressure switch if employed) is closed,
the compressor contactor is energized. Upon shutdown
the delay or break timer starts and prevents restart until
the delay on break and delay on make periods have
expired. During routine operation of the unit with no
power interruptions the compressor will operate on
demand with no delay.
FIGURE 8
START UP LABEL
IMPORTANT
These procedures must be
followed at initial start up and at
any time power has been removed
for 12 hours or longer.
To prevent compressor damage which may
result from the presence of liquid refrigerant
in the compressor crankcase:
1. Make certain the room thermostat is in the
"off" position (the compressor is not to
operate).
2. Apply power by closing the system
disconnect switch. This energizes the
compressor heater which evaporates the
liquid refrigerant in the crankcase.
3. Allow 4 hours or 60 minutes per pound of
refrigerant in the system as noted on the
unit rating plate, whichever is greater.
4. After properly elapsed time, the thermostat
may be set to operate the compressor.
5. Except as required for safety while
servicing,
do not open system
disconnect switch
.
7961-061
