Unit Power-Up; Blower Operation And Adjustments - Lennox KGC092 Installation Instructions Manual

C-Hot Gas Reheat Units Only
Units require a dehumidify demand to initiate operation. A
24V input at DH is required to energize reheat. A
standalone dehumidistat (A20) and/or a room thermostat
/ energy management system with humidity sensing may
be used. Refer to device manual for setup details.
1- When a dehumidistat is used, route wires from the A20
dehumidistat switch to the control box. Install
dehumidistat assembly
instructions provided with the dehumidistat.
2- Connect dehumidistat and/or thermostat wiring to
TB1 as shown in figure 13.
IMPORTANT - Remove jumper between terminals R
(24V) and OC when thermostat has a night setback
mode. If reheat operation is desired during night setback,
move dehumidistat wire from OC to R.
Note - When initially setting up some thermostats, a
dehumidification mode must be enabled. When
prompted by thermostat menus, select RTU/AUX
DEHUMIDIFIER mode.

Unit Power-Up

A-General
1- Make sure that unit is installed in accordance with the
installation instructions and applicable codes.
2- Inspect all electrical wiring, both field‐ and
factory‐installed, for loose connections. Tighten as
required.
3- Check to ensure that refrigerant lines do not rub
against the cabinet or against other refrigerant lines.
4- Check voltage at main unit power connection.
Voltage must be within range listed on nameplate. If
not, consult power company and have voltage
condition corrected before starting unit.
5- Make sure filters are in place before start‐up.
6- Make sure there is no heating, cooling, or blower
demand from thermostat. Apply power to unit.

Blower Operation and Adjustments

A-Three Phase Scroll Compressor Voltage Phasing
Three phase scroll compressors must be phased
sequentially to ensure correct compressor and blower
rotation and operation. Compressor and blower are wired in
phase at the factory. Power wires are color-coded as follows:
line 1-red, line 2-yellow, line 3-blue.
1- Observe suction and discharge pressures and
blower rotation on unit start-up.
in accordance with
Page 11
If pressure differential is not observed or blower rotation is
not correct:
2- Suction pressure must drop, discharge pressure
must rise, and blower rotation must match rotation
marking.
3- Disconnect all remote electrical power supplies.
4- Reverse any two field-installed wires connected to
the line side of TB2 or F4. Do not reverse wires at VFD
or compressors.
5- Make sure the connections are tight.
Discharge and suction pressures should operate at
their normal start‐up ranges.
Supply Air Inverter Units - Units are equipped with a
phase monitor located in the control compartment. The
phase monitor will detect the phasing of incoming
power. If the incoming power is out of phase or if any of
the three phases are lost, the indicating LED on the
phase monitor will turn red and the unit will not start. In
normal operation with correct incoming power phasing,
the LED will be green.
B-Blower Operation
Initiate blower demand at thermostat according to
instructions provided with thermostat. Unit will cycle on
thermostat demand. The following steps apply to
applications using a
thermostat.
1- Blower operation is manually set at the thermostat
subbase fan switch. With fan switch in ON position,
blowers will operate continuously.
2- With fan switch in AUTO position, the blowers will
cycle with demand. Blowers and entire unit will be off
when system switch is in OFF position.
C-Blower Access
The blower assembly is secured to a sliding frame which
allows the blower motor to be pulled out of the unit. See
figure 14.
1- Loosen the reusable wire tie which secures the
blower wiring to the blower motor mounting plate.
2- Remove and retain screws on either side of sliding
frame. Pull frame toward outside of unit.
3- Slide frame back into original position when finished
servicing. Reattach the blower wiring in the previous
location on the blower motor base using the wire tie.
4- Replace retained screws on either side of the sliding
frame.
typical electro-mechanical