AEC NEC Central Station Air and Water Cooled Chiller - Manual (Page 49)

Page 48 NEC Series Water- and Air-Cooled Central Chillers
Problem Possible cause Solution
Compressor cycles at short
intervals. Freeze control setting is too
high. Lower set point to 10°F
below the leaving water
temperature you want.
Leaving water temperature is
not at the set point. Improper water/glycol
mixture. Be sure the antifreeze
mixture protection is right for
the process.
Defective freezestat control. Replace.
Refrigerant low pressure
switch is set too high. Call service to adjust
pressure control.
R-22 cutout = 30 psi.
The refrigerant charge is low. Call service to find and repair
the leak—add refrigerant.
Auxiliary pump pressure is
too high. Restricted water flow. Check for partially closed
valves, etc. Make sure that
all lines are properly sized.
Unit runs continuously, but Restricted condenser air. Clean condenser.
without enough cooling Unit low on refrigerant. Call service.
power. Inefficient compressor. Call service.
Unit under-sized for your
application. Call sales rep.