Siemens LMV3 series, Technical Instructions

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Technical Instructions LMV Series
Document No. LV3-1000
Appendix A Page 26 SCC Inc.
Revert to Pilot - LMV37 only (continued)
7. Once the ignition position has been reached, the LMV37 pauses for the length of
interval 2 - main stabilization (phase 65).
8. After the interval 2 time has expired, both the ignition transformer and pilot valve are
energized for the length of safety time 1 (phase 66).
9. After safety time 1 expires, the main valves (V1 and V2) are de-energized (phase 67).
Both the ignition transformer and pilot valve remain energized for the length of safety
time 1 to ensure that the pilot is stable while the main flame is extinguished.
10. After safety time 1 expires again, the ignition transformer de-energizes, and the pilot
valve remains energized (phase 68). The LMV37 is now in “revert to pilot” mode.
11. The LMV37 will remain in “revert to pilot” mode until one of three situations occurs:
a. The pressure or temperature falls enough so that the contact between terminals
6N and 6P on the RWF55 closes, re-energizing terminal X5-03.2.
b. The maximum pilot on time is reached.
c. The pressure or temperature climbs enough so that the contact between
terminals 1N and 1P on the RWF55 opens, de-energizing terminal X5-03.1.
If Option “a” occurs:
The LMV37 will proceed with a normal light-off sequence, except that it will start the sequence
at the end of the pilot stabilization time (phase 44) and then progress to normal operation
(phase 60).
If Option “b” occurs:
The LMV37 will postpurge and then recycle to standby (phase 12) just like a normal shutdown.
If the contact between terminals 1N and 1P on the RWF55 is still closed and the contact
between terminals 6N and 6P is still open, the LMV37 will go through the startup sequence
again and stop in pilot stabilization (phase 44). If the contact between terminals 6N and 6P on
the RWF55 closes at any time during the startup sequence, the LMV37 would continue to light
off past phase 44 and proceed to normal operation (phase 60).
If Option “c” occurs:
The LMV37 will postpurge and then recycle to standby (phase 12) just like a normal shutdown.
The LMV37 will wait in standby until the contact between terminals 1N and 1P on the RWF55
closes, at which time the LMV37 will go through a normal startup sequence and proceed to
normal operation (phase 60).