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Building Technologies Division
Basic documentation LMV36...
CC1P7544en
Infrastructure & Citiies Sector
7 Basic unit
25.09.2013
7.3 Digital
inputs
7.3.1 Safety loop X3–04 (optional pressure switch-max (Pmax)),
pin 1 and 2
Input for connection of the safety loop. When any of the series-connected contacts
included in the loop opens, power supply to the fuel valves, the fan and the ignition
equipment is instantly cut.
The safety loop includes the following components:
External burner switch (ON / OFF)
Safety limiter / safety pressure limiter (SL / SPL)
External control thermostat and / or pressurestat, if required
Water shortage switch
Note
Pressure switch-max (Pmax) when using POC via X5-02.
LMV...
Bild 273e/0409
T
6.3
IE
C
Safety loop
(optional pressure switch-max (Pmax))
Power signal for safety loop
Protective earth (PE)
Line voltage (N)
ST
B
Wa
te
r
shor
tage
Si
L
1
2
3
4
5
Figure 16: Safety loop (optional pressure switch-max (Pmax)) X3-04
For diagnostic purposes, the contacts of the components included in the safety loop and
the burner flange contact are combined for delivering the safety loop signal. If there is
no such signal, the system initiates safety shutdown in any event.
If, with
Load controller ON,
there is no signal from the safety loop (start prevention),
error code 22 is translated to text display
OFF S
(S = safety loop) and the numerical
value appears in the error history.
Error
code
Diagnostic
code
Meaning for the LMV36... system
22
OFF S
0
Safety loop / burner flange Open
For the input, a repetition counter can be parameterized. Here, it is possible to set the
number of errors permitted until lockout occurs (refer to chapter
Repetition counter
).
No. Parameter
215
Repetition limit safety loop
1 = No repetition
2...15 = 1...14 number of repetitions
16 = constant repetition
Attention!
In the safety loop, temporarily (<1 s) switching contacts must not be wired
(switch or other)!