Carrier 30H - Manual (Page 15)

TROUBLESHOOTING GUIDE (Coni)
SYMPTOM
System noises
Chattering unloader
Freeze-up
Hot liquid line
Frosted liquid line
Compressor will not unload
Compressor will not load
PROBABLE CAUSE
Piping vibration
Expansion valve hissing
Compressor noisy
REMEDY
Support piping as required.
Check for loose pipe connectors.
Add refrigerant.
Check for plugged liquid line
strainer.
Check valve plates for valve noise.
Replace compressor (worn
bearings).
Stuck check valve in valve plate
Improper charging
■ Improperly set safety thermostat
Operating with safety thermostat
bypassed
Improper circulation of chilled
water
System not drained for winter
shutdown
High suction
: Shortage of refrigerant due to leak
: Expansion valve opens too wide
Receiver shutoff valve partially
closed or restricted.
Restricted filter-drier
Burned out coil
Leaky bypass piston
Stuck needle valve
Miswired solenoid
plugged bypass port (low side)
Weak bypass piston spring
Damaged bypass piston
Stuck needle valve
i Miswired solenoid
Plugged bypass port strainer
(high side)
Stuck check valve in valve plate
Check for loose compressor hold­
down bolts.
Examine check valve components,
clean or replace as necessary.
Make sure that a full quantity of
water is flowing thru the cooler
while charging and that suction
pressure in cooler is equal to or
greater than that corresponding to
32 F (58 psig for Refrigerant 22).
Check safety thermostat for proper
setting at beginning of each
season.
if thermostat was bypassed for
checking, be sure it is back in the
circuit before starting the unit.
Use ample size cleanable strainer
in the chilled water circuit. Make
sure strainer is clean. It may some­
times be necessary to chemically
treat the water to prevent forma­
tion of deposits.
Be sure and remove drain plugs at
end of cooling season. Blow out
any residual water. Instead of
draining, a suitable antifreeze may
be added to the water. Damage to
the chiller due to freezing is con­
sidered abuse and is not covered
by the warranty.
Repair leak and recharge.
Adjust expansion valve.
Open valve or remove restriction.
Remove restriction or replace
filter-drier core.
Replace coil.
Clean or replace.
Clean.
Wire correctly.
Clean.
Replace.
Replace.
Clean.
Wire correctly.
Clean.
Examine check valve components,
clean or replace as necessary.
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