Lennox KGC Series Unit Information page 48

N-Hot Gas Reheat Start-Up and Operation
General
Hot gas reheat units provide a dehumidifying mode of
operation. These units contain a reheat coil adjacent
to and downstream of the evaporator coil. Reheat coil
solenoid valve, L14, routes hot discharge gas from the
compressor to the reheat coil. Return air pulled across
the evaporator coil is cooled and dehumidified; the reheat
coil adds heat to supply air. See FIGURE 40 for reheat
refrigerant routing.
L14 Reheat Coil Solenoid Valve
When room conditions close the dehumidistat switch, L14
reheat valve is energized and refrigerant is routed to the
reheat coil.
Reheat Setpoint
Reheat is factory-set to energize when indoor relative
humidity rises above setpoint. Reheat will terminate when
the indoor relative humidity falls below or the digital output
deenergizes. Turn the knob on the dehumidistat to adjust
the setpoint.
Check-Out
Test hot gas reheat operation using the following
procedure.
REHEAT MODE REFRIGERANT ROUTING
FIGURE 40
Page 48
1 - Make sure reheat is wired as shown in wiring
section.
2 - Initiate a dehumidification demand by adjusting
dehumidistat setpoint
relative humidity. The blower , compressor 1 and
compressor 2 should be operating.
3 - End a dehumidification demand by adjusting
setpoint knob ABOVE indoor relative humidity. The
blower, compressor 1, and compressor 2 should
deenergize.
Default Reheat Operation
TABLE 25
Reheat Operation - Two Cooling Stages - Default
T'stat and Humidity
Demands
Reheat Only
Reheat & Y1
Reheat & Y1 & Y2
*If there is no reheat demand and outdoor air is suitable, free cooling
will operate.
**If there is no reheat demand and outdoor air is suitable, free cooling
and compressor 1 will operate
REFRIGERANT
CIRCUIT 1
REFRIGERANT
CIRCUIT 2
REHEAT
VALVE
CONDENSER COIL
CHECK
VALVE
EXPANSION
VALVES
knob BELOW
Operation
Compressor 1 Reheat
Compressor 1 Reheat &
Compressor 2 Cooling*
Compressor 1 Cooling &
Compressor 2 Cooling**
.
DRAWING SHOWS
102/120
092/102 STG 1
120/150 STG 2
092/102 STG 2
120/150 STG 1
indoor