Burnham K50 manual Operating and safety controls. Should any

the Q179C Pilot provides solid state electronic Flame

burners and pilot burners are immediately

Safeguard Protection that will not allow the main gas

extinguished. Normal operation can be resumed

valves to open on “call for heat” for that will shut

when the cause of safety switch malfunction

down main burners within 0.8 second if pilot flame

is corrected. Make sure all manual resets are

is not “proved”. Protectorelay will lockout on safety

activated where involved.

shutdown within 15 seconds if there is a pilot flame

(2)

PILOT FAILURE

failure on start or, if during the “run” cycle, pilot

(a) Pilot failure can occur during the start of

flame is not re-established. Since #3 terminal in the

operating cycle of the boiler. Any pilot

Protectorelay is de-energized at end of safety switch

failure, on the Q179C electronic pilot, after

timing, a solenoid valve in the pilot line will close and

ignition of pilot flame will close the main

thus 100% shut-off is achieved.

gas valves in 0.8 second.

a. OPERATING INSTRUCTIONS

(b) For 15 seconds after failure of the Q179

(1)

Make sure Manual Main Shut-off Valve and

pilot, the relay through terminals #3 and #4

all Pilot Valve have been off for at least five

will try to re-establish pilot flame. If not

minutes.

pilot flame can be sensed by the flame rod

(2)

Set Operating and Limit Controls to desired

circuit, terminal #3 and #4 are de-energized,

and the relay will lock out on safety.

settings.

(c) Pilot failure is caused by the following:

(3)

Turn Manual Main Shut-off Valve and Pilot

(1)

Complete loss of gas supply.

Valve to Open Position.

(4)

Turn on Main Electric Switch and Service

(2)

Poor ignition spark caused by low

Switch – Pilot will automatically light main

voltage, poor ground connection, faulty

burners.

wiring, and possibly a defective ignition

SEQUENCE OF OPERATION EE - See Fig. 48

transformer.

(3)

Low gas pressure will prevent flame rod

b. NORMAL OPERATION - 5006B thru 5014B

circuit from sensing pilot flame properly.

(1)

When the operating control calls for heat,

(4)

Unusually strong secondary air drafts

terminal #6 of RA890 Relay is energized.

can blow the pilot flame away from the

(2) A component check circuit in the RA890 Relay

flame rod momentarily causing nuisance

is activated which checks the electronic network

shutdown.

in the relay.

(5) A pilot line solenoid valve will not open

(3)

Terminals #3 and #4 of the relay are energized.

because of faulty wiring, low voltage, or

Terminal #3 opens pilot line solenoid valve

possibly the valve is defective.

supplying gas to pilot. Terminal #4 energizes

(6) A defective RA890 may be the cause

ignition transformer creating electric spark

but items (1) thru (5) should be followed

ignition at pilot.

first. Refer also to RA890 relay literature

(4)

Flame rod circuit between Q179C pilot

furnished with the control.

and RA890 proves presence of pilot flame

(d) By referring to the Sequence of Operations

electronically.

step by step operation of the system can

(5)

Terminal #4 to ignition transformer is de-

be controlled and the cause of pilot failure

energized.

can be readily found. After the cause of

(6)

Terminal #5 is energized and supplies power to

the pilot failure has been corrected, resume

the main gas valves.

normal operation by following the Lighting

(7)

Main gas valves open and main burners are

Instructions.

lighted by pilot.

d. SHUTDOWN INSTRUCTIONS

(8)

When operating control is satisfied, terminals

(1)

Close manual shut-off valves and pilot valves.

#6 and #5 are de-energized. Main Gas Valves

(2)

Turn off main electric switch.

and pilot line solenoid valve are all de-energized

8. EE CONTROL SYSTEM – 5015B thru 5026B

and main burner and pilot burner flames are

extinguished.

The 5015B thru 5026B boilers utilize two EE control

c. SAFETY SHUTDOWN

systems that are interconnected electrically thru all

(1) SAFETY SWITCH CIRCUIT

operating and safety controls. Should any of the

If limit control, low water cut-off or any other

aforementioned controls break the power supply circuit,

both EE control systems would be de-energized. The

electrical safety switch opens, power to terminal

succeeding paragraphs describe the function and

#6 in relay is interrupted thus de-energized

operation of each EE Control System. Should a pilot

terminal #5 and #3 in relay which de-energizes

failure on one EE Control System occur, the other EE

main gas valves and pilot valves. Main gas

Control System would not be affected. Thus main