Burnham Series 5B - Manual (Page 44)

44
4. EI CONTROL SYSTEM – The EI control system
utilizes a solid state ignition control which lights the
pilot burner by spark. Pilot gas is ignited and burns
during each running cycle (intermittent electric pilot).
Main burner and pilot gas are extinguished during the
“off” cycle.
This system permits the main gas valves
[Robertshaw7000 for 5006B thru 5009B, (2) V88A’s
for 5010B thru 5014B] to open, and the pilot line gas
valve to remain open, only when the Pilot Burner is
proven to be lit.
Should a loss of flame occur, the main valve closes
and the spark reoccurs within 0.8 second. The ignition
module has an internal 100% lockout function to
completely shutdown the system should the pilot gas
fail to ignite within approximately 90 seconds. Five to
six minutes after shutdown, the Ignition Module restarts
the ignition sequence. The ignition trial, shutdown, and
wait sequence continues until either the pilot lights or
the Thermostat is set below room temperature (to end
the call for heat). The ignition sequence can be reset by
setting down the Thermostat for one minute.
a. OPERATING INSTRUCTIONS
(1) Make sure all Manual Main Shut-off Valves and
all Pilot Valves have been off for at least five
minutes.
(2) Set Operating and Limit Controls to desired
settings.
(3) Turn all Manual Main Shut-Off Valves and Pilot
Valves to Open Position.
(4) Turn on Main Electric Switch and Service
Switch – Pilot(s) will automatically light main
burners.
b. NORMAL OPERATION SEQUENCE
5006B thru 5009B, see Fig. 42
5010B thru 5014B, see Fig. 43
5015B thru 5026B, see Fig. 44
c. SHUT DOWN INSTRUCTIONS
(1) Close manual shut-off valves and pilot valves.
(2) Turn off main electric switch.
d. SAFETY SHUTDOWN
(1) Safety Switch Circuit
If limit control, low water cut-off or any other
electrical safety switch opens, power to the 24V
terminal of all S8610M Ignition Controls is
interrupted thus de-energizing terminals PV and
MV. Loss of power to these terminals means
loss of power to all pilot gas valves and to main
gas valves, respectively. Thus, pilot burner and
main burner flames are extinguished.
Normal operation can be resumed when the
cause of safety switch malfunction is corrected.
Any controls with Manual Reset must be
reactivated.
(2) Pilot Failure
Pilot failure can occur during the start-up or
during the operating cycle of the boiler. Any
failure of a Q3481B pilot will close the main
gas valves controlled by this pilot within 0.8
second. For 90 seconds after pilot failure, the
Ignition Control will try to reestablish pilot
flame. If the pilot flame cannot be sensed by
the sensing probe, the module will lock out
on safety. Five to six minutes after shutdown,
the IGNITION MODULE restarts the ignition
sequence. The ignition trial, shutdown, and wait
sequence continues until either the pilot lights
or the Thermostat is set below room temperature
(to end the call for heat). The ignition sequence
can be reset by setting down the Thermostat for
one minute.
On 15 section and larger boilers, where two
manifolds, gas trains and pilot systems are
employed, failure of one pilot will not affect
operation of the other system. Thus, it is
possible to fire the boiler at a reduced rate thru
one manifold while the other is inoperative.
Pilot failure is caused by one of the following:
(a) Pilot burns yellow resulting in weak signal
from sensor to Ignition Control – may be
due to dirt or lint that has covered the lower
portion of the pilot burner – remove with a
soft brush or by vacuuming.
(b) Loss of pilot gas – may be due to faulty
pilot solenoid valve, improper wiring, loose
connections, or low voltage.
(c) Loss of signal from sensing probe – may be
faulty probe, improper or loose electrical
connection, or faulty Ignition Control.
cAUTiON
Be sure power is off when checking high voltage
connections.
For S8610M Trouble Shooting Guide, see Page 49.
SecTiON iV - OPeRATiON (continued)