Operation - Siemens LMV5 Series Technical Instructions

LMV Series
Purge Proving
2. Input X4-01.3 on the LMV5 must be configured for a blower auxiliary contact. This can
be set through the following menu path in the LMV5:
Params & Display > BurnerControl > Configuration > ConfigIn/Output >
FGR-PS/FCC = FCC

Operation

1. In phase 22, the blower motor output (X3-01.1) energizes, powering the common side of
the proving switch. Note: Since the blower motor may never turn off when using
direct start, purge proving cannot be used in conjunction with direct start on the
LMV5.
2. By the end of phase 24, the blower auxiliary contact input (X4-01.3) must be energized
or the LMV5 will lockout on a "fan contactor contact" (FCC) fault.
3. Once the proving switch makes, relay CR1 energizes and the two normally-open
contacts close.
4. The contact wired in parallel with the proving switch latches power to relay CR1 as long
as the blower is on.
5. The other contact wired off of line terminal X5-03.4 completes the circuit to the blower
auxiliary contact input (X4-01.3). At this point, the purge proving is complete and the
LMV5 will progress to phase 30 (prepurge).
SCC Inc. Page 29
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Technical Instructions
Document No. LV5-8000
Appendix A