Burnham 8H manual Sequence of Operation and Wiring Diagrams

Table 10: Sequence of Operation and Wiring Diagrams

Ignition System	Country	Fuel	Boiler Sizes	Wiring Diagram Figure		Sequence of
				Continuous	Intermittent	Operation
Standing Pilot (24V)	USA &	Natural Gas	6 & 7 Sect.	Figure 29	Figure 30	Page 36
	Canada	LP Gas
Standing Pilot	USA &	Natural Gas	6 - 10 Sect.	Figure 31	Figure 32	Page 39
(OP - 120V)	Canada	LP Gas
Standing Pilot	USA	LP Gas	8 - 10 Sec.	Figure 31	Figure 32	Page 39
(OP-CSD-1 - 120V
	USA	Natural Gas	5 - 10 Sect.	Figure 33	Figure 34
Intermittent Ignition		LP Gas				Page 42
(Honeywell EI - 24V)		Natural Gas	5 - 10 Sect.
	Canada			Figure 35	Figure 36
		LP Gas	5 - 7 Sect.
Intermittent Ignition	USA &	Natural Gas	6 - 10 Sect.	Figure 37	Figure 38	Page 47
(EP - 120V)	Canada	LP Gas		Not Available
Intermittent Ignition	USA	Natural Gas	8 - 10 Sect.	Figure 37	Figure 38	Page 47
(EP-CSD-1 - 120V)

1.Standing Pilot (24) Sequence of Operation

a.Normal Operation

i.Thermostat or operating control calls for heat. Vent Damper (if used) opens.

ii.Gas valves are energized allowing main gas flow and ignition of main burners.

iii.Call or heat ends. Gas valves are de- energized, extinguishing main flame. Vent

Damper (if used) closes.

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, Vent Damper (if used) closes. 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 and Vent Damper (if used) remains open 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 and Vent Damper (if used) remains open 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.Thermocouple: Senses pilot flame and causes gas valves to turn off main burner and pilot burner gas flow should pilot burner flame extinguish. Circulator continues to operate and Vent Damper (if used) remains open with call for heat.

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