Burnham 8H manual

6.Electronically Supervised Intermittent Ignition (EP/EP-CSD-1) Sequence of Operation

a.Normal Operation

i.Thermostat or operating control calls for heat.

ii.Terminal #6 of RM7890A Burner Control is energized, initiating a microcomputer monitored circuit test.

iii.The pilot valve (terminal 8) and ignition transformer (terminal 10) are energized. The pilot valve opens and the ignition electrode sparks, igniting the pilot.

iv.After the pilot flame is proven, the ignition terminal (10) is de-energized and the main valve terminal (9) is energized, allowing main gas flow and ignition of main burners.

“Main” gas light will be illuminated.

v.When the call for heat ends, terminal #6 is de-energized, extinguishing the pilot and main flames. “Main” gas light is de- energized.

b.Safety Shutdown

i.Limit: Automatically interrupts main burner operation when water temperature exceeds set point. Maximum allowable temperature is 250°F. Circulator continues to operate with call for heat. Normal operation resumes when water temperature falls below set point.

ii.Blocked Vent Switch: Automatically interrupts main burner operation when excessive flue gas spillage occurs.

Circulator continues to operate with call for heat. If blocked vent switch is activated, do not attempt to place boiler in operation. Correct cause of spillage and reset blocked vent switch.

iii.Flame Roll-out Switch: Automatically interrupts main burner operation when flames or excessive heat are present in vestibule. Circulator continues to operate with call for heat. Control is single use device. If flame roll-out switch is activated, do not attempt to place boiler in operation.

Correct cause of spillage and replace flame roll-out switch.

iv.RM7890A Burner Control: Automatically interrupts main burner operation if a pilot flame is not detected during the four or ten second pilot flame establishing period. The

RM7890A will lockout or recycle based on jumper settings. “Alarm” light will be illuminated. Refer to instructions supplied with RM7890A for additional control information.

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