Friedrich SM21J30A4, Руководство по обслуживанию

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TROUBLESHOOTING TOUCH TEST CHART
TO SERVICE REVERSING VALVES
MALFUNCTION OF VALVE
No voltage to coil.
Defective coil.
Low charge
Pressure differential too high.
Pilot valve okay. Dirt in one
bleeder hole.
Piston cup leak
Hot
Hot
Warm
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Hot
Warm
Cool
Cool
Cool
Warm
Warm
Hot
Hot
Cool
Cool
Cool
Cool
Cool
Cool
Cool
Raise head pressure, operate solenoid to free.
If still no shift, replace valve.
Raise head pressure, operate solenoid to free
partially clogged port. If still no shift, replace
valve.
Check unit for correct operating pressures and
charge. Raise head pressure. If no shift, use
valve with smaller port.
Replace valve
Raise head pressure, operate solenoid. If no
shift, replace valve.
Replace valve
Raise head pressure, operate solenoid. If no
shift, use valve with smaller ports.
Raise head pressure, operate solenoid. If no
shift, replace valve.
Operate valve several times, then recheck. If
excessive leak, replace valve.
Operate valve several times, then recheck. If
excessive leak, replace valve.
Stop unit. Will reverse during equalization
period. Recheck system
Raise head pressure, operate solenoid to free
dirt. If still no shift, replace valve.
Raise head pressure, operate solenoid.
Remove valve and wash out. Check on air
before reinstalling, if no movement, replace
valve. Add strainer to discharge tube. Mount
valve horizontally.
Stop unit. After pressures equalize, restart with
solenoid deenergized. If valve shifts, reattempt
with compressor running. If it still will not
reverse while running, replace the valve.
Replace valve.
Repair electrical circuit.
Replace coil.
Repair leak, recharge system.
Recheck system.
Deenergize solenoid, raise head pressure,
reenergize solenoid to break dirt loose. If
unsuccessful, remove valve, wash out. Check
on air before installing. If no movement, replace
valve, add strainer to discharge tube, mount
valve horizontally.
Stop unit. After pressures equalize, restart with
solenoid energized. If valve shifts, reattempt
with compressor running. If still no shift, replace
valve.
Check Electrical circuit and coil
Check refrigeration charge
Hot
Cool
Cool,
as (2)
*TVB
Hot
Hot,
as (1)
SUCTION TUBE to Compressor
Valve will
not shift
from cool to
heat.
Valve will
not shift
from cool to
heat.
Starts to
shift but
does not
complete
reversal.
Will not shift
from heat to
cool.
Apparent
leap in
heating.
Clogged pilot tubes.
Both ports of pilot open. (Back seat
port did not close).
Defective Compressor
Not enough pressure differential at
start of stroke or not enough flow to
maintain pressure differential.
Body damage
Both ports of pilot open.
Body damage
Valve hung up at mid-stroke. Pumping
volume of compressor not sufficient to
maintain reversal.
Both ports of pilot open.
Piston needle on end of slide leaking.
Pilot needle and piston needle leaking
Pressure differential too high
.
Clogged pilot tube.
Dirt in bleeder hole.
Piston cup leak
Defective pilot.
Defective compressor.
*TVB
Hot
Warm
Hot
Hot
Hot
Hot
*TVB
**
WVB
*TVB
*TVB
*TVB
Hot
*TVB
Valve operated satisfactorily PRIOR to compressor motor burnout – caused by dirt and small greasy particles inside the valve. TO CORRECT: Remove valve, thoroughly
wash it out. Check on air before reinstalling, or replace valve. Add strainer and filter-drier to discharge tube between valve and compressor.
NORMAL FUNCTION OF VALVE
DISCHARGE TUBE
from Compressor T
ube to INSIDE
COIL T
ube to OUTSIDE
COIL LEFT Pilot Capillary T
u
b
e
RIGHT Pilot Capillary T
u
b
e
VALVE
OPERATING
CONDITION
*TVB
Hot
*TVB
*TVB
Hot
*TVB
Hot
*TVB
**
WVB
*TVB
Hot
Hot
Hot
Warm
Hot,
as (1)
Hot,
as (1)
Warm,
as (1)
Hot
Hot
Hot
Hot
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Cool,
as (2)
Warm
Warm
Hot
Hot,
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Hot,
as (1)
Warm,
as (1)
NOTES:
* TEMPERATURE OF VALVE BODY
** WARMER THAN VALVE BODY
1 2 3 4 5 6 POSSIBLE CAUSES CORRECTIONS
Normal Hot Cool Cool Hot *TVB TVB
Cooling as (2) as (1)
Normal Heating Hot Cool Hot Cool *TVB TVB
as (1) as (2)