THERMEx THW100, Руководство по эксплуатации продукта

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Heat Pump Manual
44
TROUBLE SHOOTING
The wiring diagram above shows a typical wiring layout for the units. The way the systems
logic works is that on the control circuit all the components in the line need to be closed
before the compressor contactor can be energised and the compressor can start. In the case
shown above there is
– in order – a HP (high pressure) switch, a LP (low pressure) switch, a
CTOL (compressor thermal overload) and an EF (Enable Fan).
If all the components in this circuit are closed then the C1 fault input can close and the
controller knows to start the compressor. If anything on this circuit opens then the C1 fault
input will open and the controller will stop the compressor. The software does not know which
of these 4 switched has opened so it will just give a
“system fault”
Going along the fault circuit
High pressure fault
·
Push the reset
– OK – button on the controller and monitor pressures to check operation. See
below for high pressure causes
·
Condenser is blocking up
– check pressure drop across plate pack. Back flush may clear
debris build up
·
Pump may not be providing full flow
– check pump health – it is very important that the flow
required on the data sheet is supplied to the unit. If the correct flow is not supplied then higher
pressure will result causing reliability issues with the compressor especially at higher
temperatures. The compressor will also draw more amps and may trip the thermal overload.
·
Controller has not cut the unit out
– faulty sensor or sensor moved out of calibration
Low pressure fault
·
Evaporator coils are iced up
– defrost sensor not working or defrost solenoid not working
·
Fan not moving enough air, faulty fans or fans that may be tightening and thermal overload
may be open
·
Unit may have loss refrigerant or have small leak. Check pressures and sight glass for
evidence of refrigerant charge
·
Unit may be starved of air
– it may be installed too close to another unit or a wall
CTOL
– Compressor thermal over load – compressor is drawing too many amps
·
Compressor motor may be tightening up
·
Condenser is restricting flow or pump is undersized causing low water flow
·
Compressor has been over charged with refrigerant after a service
·
Temperature probe may not be sensing the water temperature properly
– it may have come
loose
– and the water temperature is too high
EF- Fan enable relay
– this is the fan contactor – if the fan stops for any reason then the contactor will
open and open the fault circuit on the compressor. Reasons for this can be
·
Fan thermal overload has opened
– fans motors could be drawing too much current or
something may be restricting their flow
·
The defrost function may be faulty and the coil could be freezing up and restricting air flow
If there is a system fault then all the electrical components along this circuit need to be checked for
continuity.
If the compressor should have started then check that there is 24VDC across A1 and A2 on the
contactor. If the controller is trying to start the contactor then the small green light will be shinning on the
back of the controller next to the first output
– see page 38.
If there is not 24VDC at the contactor and the controller is trying to start the compressor then something
in the circuit must be open. To check the HP and the LP then gauges will be needed although the
controller will giving resting pressures. Pressures in the system when it is sitting idle for a long period
should be around 500kPa