User Manual

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Building Technologies Division CC1N7785en
20.11.2017
Control sequence in the event of fault and indication of lockout
In case of any disturbance, the supply of fuel will immediately be interrupted. At the
same time, the sequence switch stops and thus the lockout indicator also.
The symbol appearing above the reading mark indicates the kind of fault:

No start  One of the contacts is not closed (also see Prerequisites for burner startup)
 Extraneous light
Lockout during or after completion of the control sequence
Example:
- Flame not extinguished
- Leaking fuel valves
- Faulty flame supervision circuit
=
Abortion of startup
sequence
 No OPEN signal for end switch (a) at terminal 8
 Terminals 6, 7 and 14 and, in case LOK16... is used, terminal 15, also remain live
until the fault is corrected.
P Lockout  The air pressure signal has not been received at the start of the air pressure check

Each air pressure failure after this time initiate also lockout.
 Lockout  Due to a fault in the flame supervision circuit.
>
Abortion of startup
sequence,
 Auxiliary switch (m) has not delivered the positioning signal for the low-fire position
to terminal 8.
 Terminals 6, 7 and 14 and, in case LOK16... is used, terminal 15, also remain live
until the fault is corrected.
1 Lockout  No flame signal has been received on completion of the (first) safety time.
2 Lockout Only with LGK16...:
 No flame signal has been received on completion of the second safety time (flame
signal of the main flame with interrupted pilot burners).
I Lockout  The flame signal has been lost during burner operation
 Air pressure failure
After the lockout reset, the burner control sequence switch first returns to the start
position and then initiates a burner restart.
If lockout occurs any other moment in time between start and preignition not indicated
by a symbol, the usual cause is a premature flame signal, that is, a faulty flame signal
caused, for instance, by a self-igniting UV tube.
Only with LOK16...:
 If wire link (B) was cut off and the flame is lost during burner operation, the burner
control programs a repetition of the startup sequence with the full program.