Burnham Series 5B - Manual (Page 46)

46
FIG. 43
SCHEMATIC WIRING DIAGRAM - EI CONTROL SYSTEM (V88 GAS TRAIN)
U.S.A. 5010B THRU 5014B
CANADA 5006B THRU 5014B
SEQUENCE OF OPERATION
WHEN OPERATING CONTROL CLOSES, THE ELECTRIC SPARK AND PILOT VALVE ARE AUTOMATICALLY
ENERGIZED. THE SENSING PROBE PROVES THE PRESENCE OF THE PILOT FLAME. INTERNAL SWITCH
ACTION DE-ENERGIZES THE SPARK AND ENERGIZES THE MAIN GAS VALVES STARTING MAIN BURNER
OPERATION. WHEN THE OPERATING CONTROL IS SATISFIED THE PILOT GAS VALVE AND THE MAIN GAS
VALVES ARE DE-ENERGIZED STOPPING THE BURNER OPERATION.
IN THE EVENT OF EXCESSIVE STEAM PRESSURE (STEAM BOILER) OR EXCESSIVE BOILER WATER
TEMPERATURE (WATER BOILER), THE HIGH LIMIT CONTROL WILL DE-ENERGIZE THE PILOT GAS VALVE
AND THE MAIN GAS VALVES STOPPING BURNER OPERATION.
THE LOW WATER CUT-OFF WILL ALSO STOP BURNER OPERATION IF THE WATER LEVEL IN THE BOILER
SHOULD DROP BELOW THE LOWEST SAFE LEVEL.
SecTiON iV - OPeRATiON (continued)