TM 5-3895-374-24-2
EXTENDED PREPURGE
Occasionally it is necessary to extend the pre-purge timing on the Flame Safeguard Control to greater
than 30 seconds. This can be accomplished by adding a time delay relay in the L2/M and D/8 circuit
and wired in the following manner
The maximum extended purge time will be 10 minutes. The maximum time delay setting should be
91/2 minutes. If the time delay relay does not close the D-8 circuit within 10 minutes of the start, the
FLAME-MONITOR will LOCKOUT and the message will be "LOCKOUT D-8 HI PURGE OPEN."
Auxiliary Device In M-D-8 Circuit at Flame Monitor Control
The function of the low fire start and high fire purge interlock circuits internally in a new Fireye Flame
Monitor unit is accomplished by highly reliable solid state electronic circuitry. This prohibits the
connection of power consuming devices (i.e. lamps, annunciators, relays, timers, etc.) to the D or 8
terminals.
COMBINATION FUEL BURNERS
Note: An important safety feature of the FLAME-MONITOR system is the ability to monitor the proper
timed operation of critical terminals; fuel valve terminals 5, 6 and 7for instance. Jumpering of these
terminals could therefore cause the control to sense an unusual condition and LOCKOUT.
When changing fuels on combination fuel burners if DIRECT SPARK IGNITION is used, it is normal
to jumper these terminals. To assure that burner operation is not interrupted in this situation, you must
do one of the following:
1.
Interrupt power to L1/L2 momentarily when changing fuels, before the initial burner cycle on the
new fuel.
OR
2.
Install a time delay relay contact in the jumper circuit which is timed to close 3 seconds (minimum)
after terminal 6 is energized. This method is only acceptable on programmers labeled "12" or high-
er (i.e. datecode 8710-12.)
FLAME SAFEGUARD
(page 3 - 1053)
