SHUT DOWN
ALARMS
microKool Portable Chillers UGH004/0999
6-8 TROUBLESHOOTING
Alarm
Refrigerant pressure
is either too low or
too high.
WARNING:
The microKool should
be tested and repaired
only by qualified techni-
cians equipped with the
correct tools and
trained in the mainte-
nance and repair of
electrical and refriger-
ant systems used in
industrial applications.
Possible cause
Low refrigerant pressure:
Is the refrigerant charge
low?
Is the liquid refrigerant
line restricted?
High r
efrigerant pressure
Has the water or air flow
through the condenser
become restricted?
(Continued on next page)
Solution
See
C
HECKING
R
EFRIGERANT
C
HARGE
.
Check for leaks in the
refrigerant circuit. Contact a
certified refrigerant technician
to repair and recharge the sys-
tem.
Check for closed valves or a
plugged refrigerant line.
❒ Verify that the liquid line
shut-off valve is open.
❒ Verify that the suction valve
at the compressor is open.
❒ Verify that the expansion
valve is working properly.
Check for closed valves and
obstructions, contaminants or
dirt that may have blocked or
restricted condenser efficiency.
All models:
❒ Clean the condenser coils. See
C
LEANING
C
ONDENSERS
.
Air-cooled units:
❒ Remove any obstructions to air
flow at the condenser air inlet
and outlet.
❒ Verify that the condenser fans
are working. Confirm proper
rotation and check for an elec-
trical overload.
Water-cooled units:
❒ Check for closed valves or
plugged water supply lines.
❒ Verify that the condenser water
supply is working and that
incoming water pressure is at
least 25 psi.
Refrigerant Pressure
The chiller has detected a problem that could lead to equipment
damage or personal injury if it is not corrected.
◆ The Alarm LED lights and the STOP/RUN LED flashes red.
◆ The chiller turns off the compressor, but normal operation
resumes after you clear the alarm or the problem corrects itself.
◆ The control displays a red LED or alarm code indicating the
source of the problem.
