Page 51
NOTE - COMPRESSOR MONITOR CANNOT BE
USED WITH OPTIONAL LOW AMBIENT KIT. OPĆ
TIONAL FIELD INSTALLED COMPRESSOR MONIĆ
TOR MUST BE DISCONNECTED BEFORE ALLOWĆ
ING LOW AMBIENT KIT TO BE USED.
17-Low Ambient Kit
The optional low ambient kit (figure 27) allows for mechanical
cooling operation at low outdoor temperature.
Low ambient pressure switch is wired in series with the conĆ
denser fan L1 lead. Refer to low ambient kit installation instrucĆ
tion manual for detailed installation instructions.
FIGURE 27
TYPICAL INSTALLATION
LOW AMBIENT
PRESSURE
SWITCH
HIGH PRESSURE
SWITCH
DISCHARGE
LINE
LOSS OF
CHARGE
SWITCH
VALVE
DEPRESSOR TEE
SHOCK
LOOP
LOW AMBIENT KIT
The low ambient pressure switch cycles the condenser fan
while allowing normal compressor operation. This intermitĆ
tent fan operation results in a high evaporating temperature
which allows the system to operate without icing the evapoĆ
rator coil and losing capacity.
Adjustment:
The low ambient pressure switch is adjustable but the adjustĆ
ment knob does not adjust CUT-IN or CUT-OUT points. CUT-
IN point is fixed and cannot be adjusted. The scale on the
switch measures the difference in pressure between preset
CUT-IN and adjustable CUT-OUT points. Adjustment knob
changes CUT-OUT point by adjusting the DIFFERENCE beĆ
tween CUT-IN and CUT-OUT.
The low ambient pressure switch is factory set to CUT-IN at
285psig with a difference of 146psig (CUT-OUT at 140psig).
Adjustment should not be needed. If adjustment is needed,
adjust the switch as follows:
1- Loosen knob securing screw to allow knob stop to pass
over fixed stop on control (see figure 28).
DIFFERENCE (set by knob) = CUT-IN POINT (fixed) minus
CUT-OUT POINT
FIGURE 28
LOW AMBIENT ADJUSTMENT DETAIL
ROTATE COUNTERCLOCKWISE
FIXED
STOP
KNOB
SECURING
SCREW
ADJUSTMENT
KNOB
LOW AMBIENT
CONTROL
SET INDICATOR
AT 140 PSIG
LOW AMBIENT ADJUSTMENT
To find CUT-OUT point, re-arrange the equation so that:
CUT-OUT = CUT-IN minus the DIFFERENCE.
2- Rotate the knob as needed to set the difference indicaĆ
tor at 145psig (1000kPa).
3- Tighten the securing screw after adjusting.
18-Roof Curb Power Kit
Optional Roof Curb Power kit allows line and low voltage
power to be brought into unit from RMF16 roof mounting
frame. Two 7/8" knockouts are provided along the long rails
of each mounting frame. All components in Roof Curb PowĆ
er kit are field assembled and field installed.
19-Transitions
Optional supply/return transitions (SRT16 AND SRTH16)
are available for use with downflow CHA/CHP16/20s utilizĆ
ing the optional RMF16 roof mounting frame. The transition
must be installed in the RMF16 mounting frame before
mounting the CHA/CHP16/20 to the frame. Refer to the
manufacturer's instructions included with the transition for
detailed installation procedures.
20-Supply and Return Diffusers
Optional flush mount diffuser/return FD9-65 and extended
mount diffuser/return RTD9-65 are available for use with the
CHP16. Refer to the manufacturer's instructions included
with the transition for detailed installation procedures.
21-Filter Switch Kit
An air filter switch kit is available for use with SP11 and
SSP11. The switch is activated by high negative pressure in
the blower compartment caused by dirty air filters or other reĆ
strictions. When high negative pressure causes the switch to
close, power is routed from R" thermostat wire lead through
the switch to the red FILTER" light in the status panel.
To Next Page
Loading...
Need help?
General
