Maritime Geothermal TF-45, Инструкция по установке и обслуживанию

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Page 56 001223MAN-05 1-Jul-2017
HYDRONIC OPERATION TROUBLESHOOTING
Fault
Possible Cause Verification Recommended Action
Low Suction
Pressure
(continued)
TXV stuck almost closed or
partially blocked by foreign
object.
Adjusting the TXV does not affect the
superheat or the suction pressure. TXV
may be frosting up.
Adjust the TXV all the way in and out
a few times to loosen it. Replace
TXV if this does not work.
Faulty NC solenoid valve or
wiring (valve is open or leak-
ing).
Coil is energized when it should not be,
or valve is cold.
Replace valve or correct wiring.
Low refrigerant charge. Entering liquid temperature, flow and
entering air temperature are good but
suction is low. Check static refrigeration
pressure of the unit for a very low value.
Locate the leak and repair it. Spray
nine, a sniffer, and dye are common
methods of locating a leak.
High Suction
Pressure
(may appear to
not be pumping)
Leaking reversing valve. Reversing valve is the same tempera-
ture on both ends of body, common
suction line is warm, compressor is run-
ning hot.
Replace reversing valve.
TXV adjusted too far open. Verify superheat. It should be between
8-12°F (3-6°C). Superheat will be low if
TXV is open too far.
Adjust TXV to obtain 8-12°F (3-6°C)
superheat.
Faulty compressor, not
pumping.
Pressures change only slightly from stat-
ic values when compressor is started.
Replace compressor.
TXV stuck open. Adjusting the TXV does not affect the
superheat or the suction pressure. Low
super heat and discharge pressure.
Adjust the TXV all the way in and out
a few times to loosen it. Replace
TXV if this does not work.
Compressor
frosting up
See Low Suction
Pressure in this section.
TXV frosting up
TXV stuck almost closed or
partially blocked by foreign
object.
Adjusting the TXV does not affect the
superheat or the suction pressure.
Adjust the TXV all the way in and out
a few times to loosen it. Replace
TXV if this does not work.
Random high
pressure trip
(does not occur
while on site)
Faulty compressor contactor. Points pitted or burned. Contactor
sometimes sticks causing the compres-
sor to run when it shouldn’t, tripping the
high pressure control.
Replace contactor.
Intermittent Indoor circulator. Verify wiring is good. Correct the wiring or replace the cir-
culator.
Leaking reversing valve. Reversing valve is the same tempera-
ture on both ends of body, common suc-
tion line is warm, compressor is running
hot.
Tap reversing valve, and switch it
back and forth between heating and
cooling positions. If this does not
work, replace reversing valve.
Leaking 4-way (condenser
select) valve.
4-way valve is the same temperature on
both ends of body, common suction line
is warm, compressor is running hot.
Does not work in air heat or water heat
but does work in air cool.
Replace 4-way valve.