AEC Glacier Series Air and Water Cooler Portable Chillers - Manual (Page 44)

Glacier Series Portable Chillers Page 43
4-6 Low Pressure Cutout
This electro-mechanical safety feature prevents the evaporator temperature from dropping below
a pre-set point.
It is factory set to open the control circuit at 32 psi for R-22. This permits 20°F (-7°C) operation
with a 70% water, 30% ethylene glycol coolant mixture. This control automatically resets when
the refrigerant pressure reaches 50 psi.
4-7 Oil Pressure Safety Switch
This safety feature is a differential pressure switch that monitors crankcase oil pressure.
If the pressure should drop to an unsafe level for more than two minutes, the switch will open the
control circuit.
Important!
The oil pressure safety switch is a manual reset control.
Call a refrigeration service technician to
analyze the problem and to reset the control.
4-8 Fan Cycling Switch
Air-Cooled Models Only
NXGA-5 and NXGA-7.5 Models
These models have one fan. The fan cycling switch turns on the fan when the condenser pressure
reaches 275 psi and turns it off when the pressure drops below 200 psi.
NXGA-10 through NXGA-25 Models
These models have two fans (NXGA-10 & NXGA-15) or two blowers (NXGA-20 & NXGA-
25). One turns on every time the compressor operates.
The fan cycling switch turns on the second fan when the condenser pressure reaches 275 psi and
turns it off when the pressure drops below 200 psi.
NXGA-10 Through NXGA-25 Models with the Optional Fan Cycling Switch
Glacier Series portable chillers may be supplied with an optional fan cycling switch for
applications with low ambient air temperatures. This switch cycles the second fan or blower
ON
and OFF to maintain efficient condensing pressures.