Siemens LME7 Series, Basic Documentation

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Building Technologies Division Basic Documentation LME7... CC1P7105en
Infrastructure & Cities Sector 6 Function 29.11.2011
6 Function
6.1 Preconditions for burner startup

Burner control must be reset

All contacts in the line are closed, there is a request for heat

No undervoltage

Air pressure switch or POC must be in its no-load position, or Dbr1 is connected to
X2-02 (depending on program sequence)

Flame detector is darkened and there is no extraneous light

All contacts in the safety loop are closed
6.2 Undervoltage

Safety shutdown from the operating position takes place should mains voltage drop
below about AC 75 V (UN = AC 120 V)

Restart is initiated when mains voltage exceeds about AC 100 V (UN = AC 120 V)

Safety shutdown from the operating position takes place should mains voltage drop
below about AC 165 V (UN = AC 230 V)

Restart is initiated when mains voltage exceeds about AC 195 V (UN = AC 230 V)
6.3 Controlled intermittent operation
Depending on parameter 239, after no more than 24 hours of continuous operation, the
burner control initiates automatic controlled shutdown followed by a restart, against
parameter 239.