22
NORMAL COOLING
For 48/50LC04-06 units, refrigerant flows from the outdoor
condenser and is diverted at the energized Reheat Liquid Valve
(RLV) and flows through the de-energized Cooling Liquid
Valve (CLV) to the expansion device bypassing the reheat con-
denser coil. The RDV is closed (see Fig. 13)
For 48/50LC07-26 units, refrigerant flows from the outdoor
condenser through the de-energized 3-Way Liquid Diverter
Valve (LDV) to the expansion device bypassing the reheat con-
denser coil. The Reheat Discharge Valve (RDV) is closed. (See
Fig. 14.)
DEHUM/MECH COOLING (SUBCOOLING MODE)
This mode increases latent heat removal and decreases sensible
cooling compared to normal cooling.
For 48/50LC*04-06 units, refrigerant flows from the outdoor
condenser through the de-energized Reheat Liquid Valve
(RLV) and through the reheat condenser coil to the expansion
device. The Reheat Discharge Valve (RDV) and Cooling Liq-
uid (CLV) are closed. (See Fig. 15.)
For 48/50LC*07-26 units, refrigerant flows from the outdoor
condenser, through the energized 3-Way Liquid Diverter Valve
(LDV) and through the reheat condenser coil to the expansion
device. The Reheat Discharge Valve (RDV) is closed. (See
Fig. 16.)
DEHUMIDIFICATION (HOT GAS REHEAT MODE)
This mode provides maximum latent cooling with little to no
sensible capacity. This mode can operate to provide dehumidi-
fication when there is no cooling demand.
For 48/50LC*04-06 units, The refrigerants flows from the out-
door condenser, through the de-energized RLV and through the
reheat condenser coil to the expansion device. The Cooling
Liquid Valve (CLV) is closed. (See Fig. 17.)
For 48/50LC*07-26 units, the refrigerant flows from the out-
door condenser, through the energized 3-Way Liquid Diverter
Valve (LDV) and through the reheat condenser coil to the ex-
pansion device. (See Fig. 18.)
For 48/50LC*04-26 units, the Reheat Discharge Valve (RDV)
is open, which provides some compressor discharge gas to the
reheat condenser to further increase the reheat of the evapora-
tor air stream. (See Fig. 17 and 18.)
REHEAT CONTROL
When there is only a cooling demand, the unit will operate in
normal cooling mode. When there is only dehumidification de-
mand, the unit will operate in Dehumidification mode (Hot
Gas Reheat). When there is both cooling demand and dehu-
midification demand, the unit will operate in Dehum/Mech
Cooling mode (Subcooling). During Dehumidification and De-
hum/Mech cooling mode, the unit will run all cooling stages.
When the Outside Air Temperature is above 80°F, the Outdoor
Fans will run at maximum fan speed. When the Outside Air
Temperature is below 80°F, the Outdoor Fans will modulate to
maintain Saturated Discharge Temperature setpoint LA DE-
HUM LEV 1, LA DEHUM LEV 2 and LA DEHUM LEV,
(SETTINGS UNIT CONFIGURATIONS COOLING
LOW AMBIENT). The unit can be restricted from reheat
operation by the outside temperature HUMZ LOCKOUT OAT
(SETTINGS UNIT CONFIGURATIONS COOLING
HUMZLOCKOUT OAT) sets the lowest outside tempera-
ture the unit is allowed to run reheat control (Default = 40°F).
Table 13 — Humidi-MiZer System Control Modes (Sizes 04-06)
DEMAND AND MODE OUTPUTS 48/50LC 04-06 VALVES
Space Humidity
Circuit Cooling
Demand
Circuit Mode
Circuit
Compressor
RDL Valve RLV Valve CLV Valve
— — No power Off Off (closed) Off (open) Off (open)
Low
No Off Off Off (closed) On (closed) Off (open)
Yes Cool On Off (closed) On (closed) Off (open)
High
Yes
Dehum/Mech
Cooling
On Off (closed) Off (open) On (closed)
No Dehum On On (open) Off (open) On (closed)
Table 14 — Humidi-MiZer System Control Modes (Sizes 07-26)
DEMAND AND MODE OUTPUTS
48/50LC 07-26
VALVES
Space Humidity Circuit Cooling Demand Circuit Mode Circuit Compressor
LDV Valve
3-way
RDV Valve
2-way
— — No power Off Off Off (closed)
Low
No Off Off Off Off (closed)
Yes Cool On Off Off (closed)
High
Yes Dehum/Mech Cooling On On Off (closed)
No Dehum On On On (open)
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