
5703827-XIM-A-0319
Johnson Controls Ducted Systems
51
Start-up for cooling operation
Prestart check list
After the installation is complete, complete the following checks.
1.
Check the electrical supply voltage being supplied. Make sure that it is the same as listed on the unit nameplate.
2.
Set the room thermostat to the off position.
3.
Turn on electrical power to the unit.
4.
Set the room thermostat fan switch to on.
5.
Check the indoor blower rotation.
• If the blower rotation is in the wrong direction, see the “Blower rotation” section on page 27.
Check blower drive belt tension.
6.
Check the unit supply air (CFM).
7.
Measure the evaporator fan motor's amp draw.
8.
Set the room thermostat fan switch to off.
9.
Turn off electrical power to the unit.
Operating instructions
1.
Turn on electrical power to the unit.
NOTE:
Prior to each cooling season, the crankcase heaters where equipment must be energized at least 10 hours before the
system is put into operation.
2.
Set the room thermostat setting to lower than the room temperature.
The first stage compressors energize after the built-in time delay of five minutes.
Post start check list
1.
Verify the proper system pressures.
2.
Measure the temperature drop across the evaporator coil.
Troubleshooting
WARNING
Troubleshooting of components may require opening the electrical control box with
the power connected to the unit.
Use extreme care when working with live
circuits!
Check the unit nameplate for the correct line voltage and set the voltmeter
to the correct range before making any connections with line terminals.
When not necessary, shut off all electric power to the unit prior to any of the
following maintenance procedures so as to prevent personal injury.
CAUTION
Label all wires prior to disconnection when servicing controls. Wiring errors can
cause improper and dangerous operation, which could cause injury to person and/or
damage unit components. Verify proper operation after servicing.