035-18575-001-A-1102
Unitary Products Group
21
START-UP
CRANKCASE HEATER
The crankcase heater must be energized at least 8
hours before starting the compressor. To energize the
crankcase heater, the main disconnect switch must be
closed. During this 8 hour period, the system switch on
the room thermostat must be “OFF” to prevent the
compressor from starting. Make sure that the bottom of
the compressor is warm to the touch to prove crank-
case heater operation.
PRE-START CHECK
Before starting the unit, complete the following check
list:
1.
Have sufficient clearances been provided?
2.
Has all foreign matter been removed from the inte-
rior of the unit (tools, construction or shipping
materials, etc.)?
3.
Have the condenser fans been rotated manually to
check for free rotation?
4.
Are all wiring connections tight?
5.
Does the available power supply agree with the
nameplate data on the unit?
6.
Is the control circuit transformer set for the proper
voltage?
7.
Have the fuses, disconnect switch and power wire
been sized properly?
8.
Are
all
compressor
hold-down
nuts
properly
secured?
9.
Are any refrigerant lines touching each other or any
sheet metal surface? Rubbing due to vibration
could cause a refrigerant leak.
10. Are there any visible signs of a refrigerant leak,
such as oil residue?
11. Is any electrical wire laying against a hot refrigerant
line?
INITIAL START-UP
1.
Supply power to the unit through the disconnect
switch at least 8 hours prior to starting the com-
pressor.
2.
Move the system switch on the thermostat to the
AUTO or COOL position.
3.
Reduce the setting of the room thermostat to ener-
gize the compressor.
4.
Check the operation of the evaporator unit per the
manufacturer’s recommendations.
5.
With an ammeter, check the compressor amps
against the unit data plate.
6.
Check for refrigerant leaks.
7.
Check for any abnormal noises and/or vibrations,
and make the necessary adjustments to correct fan
blade(s) touching shroud, refrigerant lines hitting
on sheet metal, etc.
8.
After the unit has been operating for several min-
utes, shut off the main power supply at the discon-
nect
switch
and
inspect
all
factory
wiring
connections and bolted surfaces for tightness.
OPERATION
NOTE: The timing intervals described in the following
procedures are nominal. Some variations will
naturally occur due to differences in individual
components, or due to variations in ambient
temperature or line/control voltage. Refer to
the wiring labels inside of the unit control
access panel for additional information.
SEQUENCE OF OPERATION
OVERVIEW
These series of condensing units, come factory
equipped with Simplicity
controls to monitor all unit
functionality and safety controls.
Do not attempt to start the compressor without
at least 8 hours of crankcase heat or compres-
sor damage can occur.
