Troubleshooting - Trane MERCURY EDAB 1105A Technical Manual

Troubleshooting

Troubleshooting is made easier by the indications on the control panel display: when an alarm signal is displayed, consult
the control panel instruction manual. If necessary, call the nearest Service Centre describing the nature of the fault and its
possible cause displayed on the control.
PROBLEM
THE UNIT DOES NOT
START
TEMPERATURE CONTROL
PROBLEM
THE ROOM
TEMPERATURE IS
TOO HIGH
ROOM TEMPERATURE
TOO LOW
PKG-SVX19B-E4
POSSIBLE CAUSE
A) No power supply to the unit's electrical panel.
B) No power to the auxiliary circuits.
C) The control panel does not start the unit.
POSSIBLE CAUSE
A) The parameter settings on the control panel are
not correct.
B) The air flow is low or absent.
C) The temperature sensor is not working.
D) The thermal load is higher than expected.
E) The three-way valve is not working.
F) There is an insufficient chilled water flow.
G) The chilled water temperature is too high.
H) The compressor(s) not working despite control
call
A) The parameter settings on the control are not
correct
B) There is insufficient power supply to the elcttric
heaters or the heaters are not working
C) The hot water coil is not working.
D) The hot gas coil is not working during
dehumidification with re-heat.
E) The three way valve of the chilled water circuit is
blocked open.
CHECK/CORRECTIVE ACTION
Check that the power is on and the unit main switch
on the electrical panel is closed.
1) Check that the IM automatic circuit breaker on
the AUX circuit is set.
2) Check the fuse on the main board.
Check that the control panel connectors are
correctly located in their sockets.
CHECK/CORRECTIVE ACTION
See control panel instruction manual
See «LACK OF / ABSENT AIR FLOW».
Check the electrical connections and the control
configuration.
Check the room's thermal load.
Check the electrical connections of the servomotor
valve.
Open the valve by means of the manual control
knob.
Check the chilled water supply; check that the shut-
off valves are open.
Check the chilled water funtion.
See «THE COMPRESSOR(S) DOESN'T / DON'T
WORK».
See «THE COMPRESSOR(S) DOESN'T / DON'T
WORK».
See the microprocessor control manual.
1) Check that the IM of the heating element is
armed.
2) Check the electric feeding circuit of the heaters.
3) If there is a heater alarm, remove the cause and
re-set the safety thermostat.
1) Check the hot water capacity and temperature.
2) Check the function of the regulation valve (see
valve and servomotor).
1) Check the hot gas 3 way valve function.
2) Check the function of the compressor serving
the re-heat. See «THE COMPRESSOR(S)
DOESN'T / DON'T WORK».
Close the valve using the manual control knob and
replace the servomotor.
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