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Building Technologies
Basic Documentation LMV5...
CC1P7550en
4 Burner control
22.05.2018
4.1.4
High temperature supervision (only LMV50)
Temperature supervision for high-temperature plants >750° to DIN EN 746-2.
Replacement of flame supervision by supervising the combustion chamber wall
temperature by means of an external safety limit thermostat to DIN EN 14597.
The external safety limit thermostat must issue the high-temperature signal (mains voltage
ON/OFF) via a switching contact.
The signal is evaluated at LMV5 input X6-01 pin 3 (
HeavyOilDirStart).
To do this, the input
must be configured to
HeavyOilDirStart
.
Parameter
HeavyOilDirStart (
deactivated / activ 38/44 / 38/44..62 /
act 21..62 / HTempGuard / ext.FlameGd
)
During a burner start with temperatures <750 °C, conventional flame supervision using a
flame detector suitable for continuous operation at LMV5 input X10 is performed.
The startup includes an extraneous light test as well as prepurging and valve proving
function, if necessary.
During operation, conventional flame supervision is ended as soon as the high-
temperature signal (temperature >750 °C) of the external safety limit thermostat is present
at LMV5 input X6-01 pin 3.
If the high-temperature signal is no longer present during operation, conventional flame
supervision is performed.
If the high-temperature signal is present during standby and during the startup sequence
no conventional flame supervision is performed (no extraneous light test).
In addition, prepurging and the valve proving phases are skipped (jump from phase 22 to
phase 36).
Conventional flame supervision is then not performed during operation.
If a high-temperature signal is present during shutdown, conventional flame supervision
does not take place.
A second switching contact (redundancy contact) can also be used for the external safety
limit thermostat.
This must always be inverse to the first switching contact:
- Mains voltage present = no flame
- Mains voltage not present = flame
This contact can be connected to input X6-01 pin 1 (start release oil) if the input has been
parameterized to
HT/FG-RedCo
.
Parameter StartReleaseOil
(HT/FG-RedCo)
Attention!
Flame detectors (QRI, QRA7, ionization probes) that are suitable for continuous
operation must be used in conjunction with high-temperature supervision