Specifications

11
TROUBLESHOOTING (Cont)
Symptoms
PROBABLE
CAUSE
REMEDY
Leak in system Repair leak
Plugged or stuck
compressor snifter valve
Repair or replace
Oil trapped in line Check piping for oil
traps
Compressor
Loses oil
Crankcase heaters not
energized during
shutdown
Replace heaters check
wiring and auxiliary
contacts
Frosted or
sweating suction
line
Expansion valve
admitting excess
refrigerant
Adjust expansion valve
Shortage of refrigerant
due to leak
Repair leak and
recharge
Hot liquid line
Expansion valve opens
too wide
Adjust expansion valve
Receiver shut off valve
partially closed or
restricted
Open valve or remove
restriction
Frosted liquid line
Restricted filter drier Remove restriction or
replace filter drier
Burned out coil Replace coil
Leaky bypass piston Clean or replace
Stuck needle valve Clean
Misfired solenoid Wire correctly
Plugged bypass point
(low side)
Clean
Compressor will
Not unload
Weak bypass piston
spring
Replace
Damaged bypass piston Replace
Stuck needle valve Clean
Misfired solenoid Wire correctly
Compressor will
not load
Plugged bypass port
strainer (high side)
Clean
High suction Stuck check valve in
valve plate
Examine check valve
Components, clean or
Replace as necessary
Symptoms
PROBABLE
CAUSE
REMEDY
Chattering
unloaded
Stuck check valve
in valve plate
Examine check valve
clean or replace as
necessary
Improper charging Make sure that a full
quantity at water is
flowing thru the cooler
while charging and
that suction pressure
in cooler is equal to or
greater than that
corresponding to 32F
(53 psig for
Refrigerant R407C)
Improperly set safety
thermostat
Check safety thermo-
stat for proper setting
or beginning of each
season
Operating with safety
thermostat bypass
If thermostat was by
passed for checking
be sure it is back in
the circuit before
starting the unit
Improper circulation of
chilled water
Use ample size clean
able strainer in the
chilled water circuit.
Make sure strainer is
Clean It may some
times be necessary to
chemically tread the
water to prevent for
motion or deposits
Freeze - up
System not for winter
shutdown
Be sure and remove
drain plus at end of
cooling season slow
out any residual water
Instead of a suitable
may be added to the
water damage to the
chiller due to freezing
is considered abuse
and is not covered by
the warranty.