Page 36
FIGURE 22
POWER EXHAUST FAN AND
BAROMETRIC EXHAUST DAMPER INSTALLATION
PEF POWER EXHAUST FAN
ASSEMBLY
(ORDERED SEPARATELY)
C6
GED GRAVITY
EXHAUST
DAMPERS
P18
Power Exhaust Setpoint Adjustment
Locate the A6 enthalpy control in the control area. The EXH
SET potentiometer is factory-set at approximately 50% of
the dial range. See figure 23. Power exhaust fans will be
energized 30 seconds after dampers are 50% open. Adjust
the EXH SET potentiometer higher (clockwise toward 10V)
to energize fans when dampers are further open. Adjust the
EXH SET potentiometer lower (counterclockwise toward
2V) to energize fans when dampers are further closed.
(Thirty-second delay allows dampers to partially open be
fore exhaust fan starts.)
H-Smoke Detectors A171 and A172
Photoelectric smoke detectors are a field installed option.
The smoke detectors can be installed in the supply air sec
tion (A64), return air section (A17), or in both the supply and
return air section.
I-Control Systems
Any two-heat, two-cool thermostat may be used. All ther
mostat wiring is connected to terminal block TB1. Each
thermostat has additional control options available. See
thermostat installation instructions for more detail.
NOTE-LHT heat pumps use standard heat cool type
thermostats. Attempted use of heat pump-type ther
mostats on LHT units will result in improper operation.
J-Drain Pan Overflow Switch S149
(optional)
The overflow switch is used to interrupt cooling operation
when excessive condensate collects in the drain pan. The
N.O. overflow switch is controlled by K220 and DL46 re
lays, located in the unit control panel. When the overflow
switch closes, 24VAC power is interrupted and after a five-
second delay unit compressors are de-energized. Once
the condensate level drops below the set level, the switch
will open. After a five-minute delay the compressor will be
energized.
FIGURE 23
A6 ENTHALPY CONTROLLER
A
B
C
D
Open
Min
Pos
Free
Cool
DCV
EXH
EXH
Set
2V 10V
DCV
Max
2V 10V
DCV
Set
2V 10V
ADJUST POWER
EXHAUST FAN
SETPOINT
ENERGIZED WHEN
DAMPER POSITION
IS HIGHER THAN
EXHAUST FAN
SETPOINT
To Next Page
Loading...
Need help?
General
