Current To The Uv Photocell; Burner Starting Up Programme - Riello GI/EMME 400 Installation, Use And Maintenance Instructions

NOTES
• 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 thus cause a new
start-up cycle.
b) there is oscillation of the max. gas pressure switch caused by excessive mains pressure (or faulty calibration)
which causes pressure switch intervention when the valves open, thus causing a new start-up cycle.

Current to the UV photocell

Min. value for a good operation: 70 µA.
If the value is lower, it can depends on:
• worked out photocell;
• low current (lower than 187 V);
• bad regulation of the burner.
In order to measure the current, use a microamperometer of 100 µA c.c., connected to the photocell, as in the
scheme, with a capacitor of 100 µF - 1 V c.c. at the same level of the instrument.
Thermostat
Motor
Ignition transformer
First valve
First flame
Second valve
Second flame
Lock out
If during the work the flame burns off, there is a lock out within 1 s.

BURNER STARTING UP PROGRAMME

Normal
6 s 12 s
49 s min.
26
Cell UV
D1143
Lock out for failed ignition
6 s 3 s max.
49 s min.