Burnham K50 Make sure all manual resets are activated where applicable

(5)Turn on Main Power Switch on both panels. Main Power Lamp on each panel will light.

(6)Turn on manual pilot valves. Both pilots should light.

(7)Turn on Manual Main Gas Valves.

(8)Turn on Main Gas Valve Switch on both panels to light burners. Main Gas Valve Lamp on each panel will light.

Proceed To Paragraph 15- Minimum Input Adjustments (for diaphragm “Lo-Hi-Lo” or motorized type gas valves)

SEQUENCE OF OPERATION EEP – See Fig. 54

b.NORMAL OPERATION – 5015B thru 5026B

(1)When the operating control calls for heat, terminal #6 of both panels and both RA890F relays are energized.

(2)A component self check circuit on each RA890F relay is activated which checks the electronic network of the relay.

(3)Terminals #3 and #4 on both panels and

RA890F relays are energized. Terminal #3 opens pilot line solenoid valve supplying gas to the Q179C pilot. Terminal #4 energizes the ignition transformer creating electric spark ignition at the Q179C pilot.

(4)Flame rod circuit between each Q179C pilot and terminal “F” on its respective RA890F proves presence of flame electronically at its Q179C pilot.

(5)Terminal #4 to ignition transformer is de- energized after flame is proven at its Q179C.

(6)Terminal #5 on each RA890F is energized supplying power to its respective main gas valves. “Main Gas Valve” panel lamps will light providing “Main Gas Valve” switches are “ON” (circuits closed).

(7)Main gas valves open and main burners are ignited by the pilot flames.

(8)When the operating control is satisfied, terminals #6 and all other terminals on both RA890F relays and panels are de-energized.

“Main Gas Valve” lamps go “OFF”, the main gas valves and pilot valve for each gas train are closed and main burners and pilot burner flames are extinguished.

(9)“Main Power” lamp remains lighted.

c.SAFETY SHUTDOWN

(1)SAFETY SWITCH CIRCUIT

Make sure all manual resets are activated where applicable.

(2) PILOT FAILURE
	(a)	Pilot failure can only occur during the
		operating cycle of the boiler. Any pilot
		failure on either of the Q179C Electronic
		Pilot, after ignition of pilot flame, will close
		the pilot valve and the main gas valves
		controlled by that particular RA890F relay
		in 0.8 second. The burners controlled by the
		other RA890F will continue to burn.
	(b)	For 15 seconds, after failure of a Q179C
		pilot, the relay through terminals #3 and
		#4 will try to re-establish pilot flame. If no
		pilot flame can be sensed by the flame rod
		circuit in 15 seconds, terminals #3 and #4
		are de-energized, and the relay will lock out
		on safety. “Pilot Failure Alarm Lamp” will
		be activated.
	(c)	Pilot failure is caused by the following:
		(1)	Complete loss of gas supply.
		(2)	Poor ignition spark caused by low
			voltage, poor ground connection, faulty
			wiring, and possibly a defective ignition
			transformer.
		(3)	Low gas pressure will prevent flame rod
			circuit from sensing pilot flame properly.
		(4)	Unusually strong secondary air drafts
			can blow the pilot flame away from the
			rod momentarily causing nuisance shut-
			down.
		(5) A pilot line solenoid valve will not open
			because of faulty wiring, low voltage, or
			possibly the valve is defective.
		(6) A defective RA890 may be the cause
			but items (1) thru (5) should be followed
			first. See also RA890 relay literature
			furnished with the panel system.
		(7)	By referring to the Sequence of
			Operations, step by step operation
			of the system can be controlled and
			the cause of pilot failure can be readily
			found. After the cause of pilot failure
			has been corrected, resume normal
			operation by following the Lighting
			Instructions on the panel.
d. SHUTDOWN INSTRUCTIONS
(1)	Turn off all switches on both panels.
(2)	Close manual shut-off valve and pilot valve.

68

If limit control, low water cut-off or any other electrical safety switch opens, power to terminal #6 and all other terminals on both RA890 relays and panels is interrupted de-energizing the main gas valves and pilot valves. Main gas burners and pilot burners are immediately extinguished. Normal operation can be resumed when the cause of safety switch malfunction is corrected.

13. THERMOCOUPLE CONTROL SYSTEM (Canada

Only)

The 5006B thru 5013B boilers are equipped with

a Thermocouple Control System that utilizes a

constant-burning Q327A pilot, a Q309 thermocouple, and a L62GB-3C Pilot Safety Switch. The Q309