IOM / Rooftop Smart and Linéa™ Range - Page 35
LOW AMBIENT KIT
LOW AMBIENT KIT
LOW AMBIENT KIT
LOW AMBIENT KIT
LOW AMBIENT KIT
The optional low ambient kit allows for mechanical cooling
operation at low outdoor temperature.
The low ambient pressure switch cycles the condenser fan
while allowing normal compressor operation. This
intermittent fan operation results in a high evaporating
temperature which allows the system to operate without icing
the evaporator coil and losing capacity.
ADJUSTMENT :
The low ambient pressure switch is adjustable but the
adjustment 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 differences in pressure
between preset CUT-IN and adjustable CUT-OUT points.
Adjustment knob changes CUT-OUT point by adjusting the
DIFFERENCE between CUT-IN and CUT-OUT.
The low ambient pressure switch is factory set to CUT-IN at
19,65 bar with a difference of 10,67 bar (CUT-OUT at 9,65
bar). Adjustment should not be needed. If adjustment is
needed, adjust the switch as follow :
1. Loosen knob securing screw to allow knob stop to pass
over fixed stop on control (see figure 45).
DIFFERENCE (set by knob) = CUT-IN (fixed) minus
CUT-OUT POINT
2. Rotate the knob as needed to set the difference
indicator at 10,0 bar.
3. Tighten the securing screw after adjusting.
To find CUT-OUT point, re-arrange the equation so that :
CUT-OUT = CUT-IN minus the DIFFERENCE.
LOW AMBIENT KIT TYPICAL INSTALLATION
Figure 44
Low ambient pressure switch
Compressor
High pressure
switch
Discharge line
Loss of charge switch
Valve depressor tee
Shock loop
LOW AMBIENT ADJUSTMENT
Figure 45
Knob securing screw
Adjustment knob
Set indicator at 965 kPa
Low ambient control
