Lme75 Phase Diagrams - Siemens LME7 Series Technical Instructions

Technical Instructions
LME-1000

LME75 Phase Diagrams

The Siemens LME7 burner controls can perform a number of different burner sequences based
upon which PME7 program module is used, how certain parameters are set, and how the LME7
is wired.
Each program module has an associated phase diagram. The phase diagrams illustrate when
input and output terminals are expected to be energized or de-energized. A legend on the
bottom of each page describes the various symbols used in the diagrams.
Notes:
1) A jumper can be added between terminals X7-04.4 and X7-01.3 for direct spark ignition.
If this jumper is added, pilot valve output X7-01.3 and main valve output X7-04.4 will be
energized from phase 40 through the end of phase 70.
2) On PME75.811A1, if the LME7 is set to perform valve proving, valve proving will always
take place during shutdown unless it is the next startup following a lockout or power loss,
or if the postpurge time (parameter 234.00) is set to 0. In that case, valve proving occurs
during startup and shutdown. When valve proving occurs during shutdown, it will happen
at the same time as postpurge. Phases 80-83 will be displayed on the LME7 and the AZL23
even though postpurge (phase 74) is also occurring at the same time. The actual
postpurge time will be at least the sum of all four valve proving time parameters (242,
243, 244, and 245). When valve proving occurs during startup, it will happen at the same
time as prepurge. Phases 80-83 will be displayed on the LME7 and the AZL23 even
though prepurge (phase 30) is also occurring at the same time. The actual prepurge time
will be at least the sum of all four valve proving time parameters (242, 243, 244, and 245).
3) If parameter 235.00 is set to 0, air pressure switch input X3-02.1 only needs to be
energized during phases 22 through 52 and during phase 74. The switch is not checked
during main burner operation.
4) If parameter 236 is set to 1, low gas pressure switch input X5-01.2 only needs to be
energized during phases 52 through 70. The input is not checked before the main valves
are open. This is useful for applications where the low gas pressure switch is mounted
downstream of the safety shutoff valves (for CSA B149.3 compliance).
Section 4 Page 8
LME Series
SCC Inc.