Manual selection, installation and maintenance
57
Roof-top units -
RTE series
-
PROBLEM
CAUSE
SYMPTOM
SOLUTION
5. INTERVENTION
OF THE HIGH
PRESSURE
SWITCH
1. One or many fans can’t
operate
- The compressor does stop
- Intervention of the general alarm
- Repair or replace fans/ fan
2. Pressure switch out of use
See 5.1.
-Verify and replace the pressure
switch
3. Excessive refrigerant
charge
See 5.1.
- Discharge the gas in excess
4. Gas presence impossible
to condensate in the cooling
circuit
See 5.1.
- Recharge it after the unit discharge
5. Condensate coil not
sufficiently run over the from
air
See 5.1.
- See 1.3, 1.4, 1.5
6. Clogged refrigerant filte
See 5.1.
- Verificare e sostituire il filtro
7. Room air temperature too
high
See 5.1.
- Verify and replace the filter
8. Hot air recirculation
caused by wrong installation
- Air outlet temperature from coil
higher than max. values permitted
- Avoid the recirculation causes
respecting the minimal distances to
wall as indicated in the imensional
schemes or avoid that the
condensate coils are run over the
hot air.
6. COMPRESSORS
FAULTS
1. Defective compressor
-The compressor does not restart
- Replace the compressor
2. Absence of a safety device See 6.1
-See par. 5 and 6
3. Defective connection or
open contacts
See 6.1
- Verify the voltage and close the
contacts
4. Power circuit open
See 6.1
- Find the intervention cause of
protection, close the compressor
automatic
5. Compressors not under
voltage
See 6.1
- Check the voltage. Close the
compressors
6. Compressors defective
actuator
- The compressor starts and stops
- Verify and eventually replace
7. EXPANSION
VALVE FAULTS
1. Expansion valve too
closed: excessive gas
overheating at evaporator
outlet
- Compressor too hot
- Open the expansion valve to
decrease the overheating
2. Expansion valve too
open: the system operates
with overheating too low.
Compressors liquid return.
- Compressor too cool and loud
- Close the expansion valve to
increase the overheating
3. Expansion valve broken:
discharged bulb or blocked
stem
- Low evaporation pressure
- Replace the valve
8. DRIER FILTER
FAULTS
1. Drier filter clogged
- Compressors suction pipe frosted
- Bubbles in the flow light
- Liquid pipe more cool at drier filter
outlet
- Clean or replace the filter
