Gas / Oil Pressure Switch-Max (Pmax) / Or Poc Contact, Start Release Oil X5-02 - Siemens LMV37.4 Series Basic Documentation

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Building Technologies Division
Industry Sector
7.3.9 Gas / oil pressure switch-max (Pmax) / or POC contact, start
release oil X5–02
Input for connection of a pressure switch-max for gas or oil: The pressure switch must
have an NC contact, which means that the contact opens when the adjusted maximum
pressure is exceeded. If the plant does not require a pressure switch-max, a wire link
must be fitted between pin 2 and 3.
Caution!
The OEM must check to see whether the burner can be operated without
pressure switch-max. This may necessitate a special approval, depending on
the type of application.
"L" for pressure switch
Pressure switch-max or POC
Protective earth (PE)
Figure 16: Gas / oil pressure switch-max (Pmax) or POC X5-02
The connection facility can also be used as POC (proof of closure) (refer to chapter
Sequence diagrams).
No. Parameter
Gas: Pressure switch-max/POC input
0 = inactive
237 1 = pressure switch-max
2 = POC
3 = Pressure switch valve proving
Note
If the input is used for POC or for pressure switch, pressure switch-max can be
included in the safety loop. In that case, pressure switch-max must not be fitted
between the valves, but downstream from them.
Gas pressure switch-max
In all types of gas trains, the maximum gas pressure is monitored from phase 40. If the
maximum gas pressure is exceeded, the system initiates lockout.
Error Diagnostic
code code
14 0
1
21 0
1
During the safety times (TSA1 / TSA2), the signal from pressure switch-max is only
assessed after a certain period time has elapsed in order to ignore the pressure shocks
that occur the moment the valves open.
No. Parameter
Gas: Time to respond to pressure faults within safety time 1 (TSA1) and safety
229
time 2 (TSA2)
Basic documentation LMV37.4...
7 Basic unit
LMV...
Bild 279e/1010
Meaning for the LMV37.4... system
POC open
POC close
Pressure switch-max (Pmax): Max. gas pressure
exceeded
POC: POC open (software version V02.00)
POC close (software version V02.00)
Pmax/POC
45/235
CC1P7546en
20.09.2013