Troubleshooting - Lennox Adnova THS Series Installation, Operating And Maintenance Manual

9

Troubleshooting

On this pages you will find a list of the most common reasons that may cause the package unit to fail or any malfunction.
This causes are broken down according to easily identifiable symptoms.
You should be extremely careful when attempting to implement any of the possible remedies
suggested: overconfidence can result in injuries, even serious ones, to inexpert individuals.
Therefore, once the cause has been identified, you are advised to contact the manufacturer or a
qualified technician for help.
Tab. 7 Fault-Causes-Corrections
FAULT
No power supply.
The electronic card is cut off from the power supply.
The unit does
not start
Alarms have been released.
The phase sequence is wrong.
The compressor
The compressor is rotating in the wrong direction.
is noisy
Insufficient airflow through the condenser.
Presence of air in the refrigerant circuit, as revealed
Presence of
by the presence of bubbles in the flow indicator also
abnormally
with sub-cooling values exceeding 5 °C.
high pressure
Unit overcharged, as revealed by a Sub-cooling of
more than 8 °C.
Thermostatic valve and/or filter obstructed. These
symptoms may also occur in the presence of an
abnormally low pressure.
Low
condensation Transducer fault.
pressure
Malfunctioning of thermostatic valve.
Filter dryer clogged.
Low evaporation
pressure
Low condensation temperature.
Low level of refrigerant.
The circuit breakers or line fuses have been tripped by
a short circuit.
The compressor
does not start One of the HP or LP pressure switches has tripped.
The phases have been inverted in the distribution
compartment.
The drain pan hole is closed.
Water out from
the unit The siphon is missing.
Unit is not perfectly level
@DNOVA THS_R410A-IOM-1304-E
POSSIBLE CAUSES CORRECTIVE ACTIONS
Check if power is being supplied both to the primary and
auxiliary circuits.
Check the fuses.
Check whether any alarms are signalled on the
microprocessor control panel, eliminate the causes and
restart the unit.
Invert two phases in the primary power line after
disconnecting them upstream from the unit.
Check the phase sequence relay. Invert the phases on the
terminal board after disconnecting the unit and contact the
manufacturer.
Check for the presence of obstructions in the condenser
section ventilation circuit.
Check whether the condenser coil surface is obstructed.
Check the condensation control device (optional).
Drain and pressurise the circuit and check for leaks. Evacuate
slowly (for more than 3 hours) until reaching a pressure of 0.1
Pa and then recharge in the liquid phase.
Drain the circuit.
Check the temperatures upstream and downstream from the
valve and filter and replace them if necessary.
Check the efficiency of the condensation control device
(optional).
Warming the bulb with your hand, check whether the valve
opens and adjust it if necessary. If it does not respond,
replace it.
Pressure drops upstream and downstream from the filter
should not exceed 2°C. If they do, replace the filter.
Check the efficiency of the condensation control device
(where present).
Check the refrigerant level by measuring the degree of Sub-
cooling; if it is below 2°C replenish the charge.
Pinpoint the cause by measuring the resistance of the
individual windings and the insulation from the casing before
restoring power.
Check on the microprocessor, eliminate the causes.
Check the phase sequence relay.
Open the front panels, remove the sheet metal just below the
e-panel (down flow units) and clean it.
Check for the presence and provide for a new one.
Place correctly the unit.
22