5144
12
BURNER STARTING DIFFICULTIES AND THEIR CAUSES (GAS)
The electrical equipment is fitted with a disk which rotates during the start-up program and can be seen
through the release inspection window. When the burner does not start or stops because of a fault, the
symbol which appears in the inspection window indicates the type of interruption fault.
THE EQUIPMENT DOES NOT START WHEN THE THERMOSTATS CLOSE
- There is no gas.
- The min. gas pressure switch does not close the contact: it is incorrectly adjusted.
- The air pressure switch is set in operating position.
- The equipment fuse has blown.
- The cam pos. 1 selector switch does not close the circuit, equipment terminals 11 and 8.
HALT AFTER START-UP
- The cam pos. 2 selector switch does not close the circuit, equipment terminals 9 and 8.
LOCK HALT
The air pressure switch does not effect a selection because of:
- a fault contact;
- insufficient air pressure.
LOCK HALT
Malfunctions of the flame detection circuit:
- photo-sensitive cell exhausted;
- fault internal amplifier.
PRE-VENTILATION HALT
- The cam pos. 3 selector switch does not close the circuit, equipment terminals 10 and 8.
LOCK HALT, no flame signal:
- ……
- photo-sensitive cell connection to the equipment is interrupted;
- insufficient electrical detection current (min. 70 µA).
LOCK HALT IN OPERATION BECAUSE OF:
- no flame signal;
- no air pressure.
N.B.:
- If the lock halt takes place between start and pre-start-up without a fault symbol appearing, the fault
is usually flame simulation.
- The burner continues repeating the start-up cycle without the lock taking place:
a) there is oscillation of the min. gas pressure switch caused by adjustment very close to the mains
pressure, so that the drop in pressure which occurs at burner start-up is sufficient to trigger action and
this cause a new start-up cycle.
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