Burnham K50 Boiler User Manual


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(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ameelectronicallyatitsQ179C
pilot.
(5) Terminal #4 to ignition transformer is de-
energizedafterame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ames.
(8)Whentheoperatingcontrolissatised,
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ames
areextinguished.
(9) “Main Power” lamp remains lighted.
c. SAFETY SHUTDOWN
(1) SAFETY SWITCH CIRCUIT
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
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ame,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ame.Ifno
pilotamecanbesensedbytheame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amerod
circuitfromsensingpilotameproperly.
(4) Unusually strong secondary air drafts
canblowthepilotame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
rst.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.
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