Maritime Geothermal EMWT-65-HACW-P-1T, Инструкция по установке и обслуживанию

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Page 28 000662MAN-03 01 MAR 2012
OPERATION TROUBLESHOOTING - COOLING MODE
Fault Possible Cause Verification Recommended Action
Heating instead
of cooling Control wiring not set up
properly or cooling select
relays not functioning. Verify that there is 24VAC across O
and C of the terminal strip when
calling for cooling. Correct control wiring or replace
relays.
Faulty reversing valve so-
lenoid coil. Verify solenoid by removing it from
the shaft while the unit is running.
There should be a loud “whoosh”
sound when it is removed. Replace solenoid if faulty.
Faulty reversing valve. A click can be heard when the coil
is energized but the unit continues
to heat instead of cool. Replace reversing valve.
High Discharge
pressure Low or no Outdoor liquid
flow Delta T across the Outdoor Loop
ports should be between 8-12°F
(4-7°C), or compare pressure drop
to the tables for the unit. Determine the cause of the flow
restriction and correct it.
Verify pumps are working for
ground loop systems. Verify well
pump and water valve is working
for ground water systems.
Entering liquid tempera-
ture too warm. Most likely caused by undersized
ground loop. Verify the ground loop sizing. In-
crease the size of the ground loop
if undersized.
Dirty or fouled coaxial
heat exchanger.
(typically for ground water,
unlikely for ground loop) Disconnect the water lines and
check the inside of the pipes for
scale deposits. Have a qualified service technician
backflush the coaxial exchanger.
OPERATION TROUBLESHOOTING - HEATING MODE
Fault Possible Cause Verification Recommended Action
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
running hot. Replace reversing valve.
Compressor
frosting up
See Low Suction
Pressure in this section.
TXV frosting up TXV stuck almost closed
or partially blocked by for-
eign 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 contac-
tor. Points pitted or burned. Contactor
sometimes sticks causing the com-
pressor to run without the fan, tripping
the high pressure control. Replace contactor.
Intermittent Hot Indoor
Loop circulator (heat ex-
changer to Hot Tank) Verify wiring is good Correct the wiring or replace the
circulator.
TXV adjusted too far
open. Verify superheat. It should be be-
tween 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.
TXV stuck open. Adjusting the TXV does not affect the
superheat or the suction pressure.
Low super heat and discharge pres-
sure.
Adjust the TXV all the way in and out
a few times to loosen it. Replace
TXV if this does not work.