Siemens LMV51 Series Basic Documentation page 275

Siemens Building Technologies
HVAC Products
19.6.2 Checking the O
Every time the burner is started up, the measured residual oxygen content is compared
with the O content of the ambient air at the end of prepurging.
2
For that purpose, the prepurging time of the LMV52... must be param-
eterized such that the combustion chamber and the flueways will be
completely purged.
Normally, this value reads 20.9 %, but it can be parameterized in the case of plants that
operate with enriched air. This test detects offset errors of the measuring cell. For this
reason, the correct setting of the air's O2 content is safety-related.
Parameter:
O
2
If the O content lies outside the tolerance band of ±2 %, one of the following reactions
2
will take place, depending on the parameterization of «O
Parameter:
O Ctrl/Guard (auto deact / man deact / O
2
conAutoDeac)
man deact O2 trim controller and O2 monitor are deactivated. No O2 test will be
(auto deact): made.
O2-guard / O2- O2 trim controller / O2 monitor is / are activated. If the test is nega-
control: tive, safety shutdown will take place, followed by a repetition if possi-
ble, otherwise lockout.
conAutoDeac: O2 trim controller and O2 monitor are activated. Option is «automatic
deactivation». If the test is negative, both the O2 trim controller and
the O2 monitor will be deactivated. The burner will be started up with-
out O2 trim control.
Basic Documentation LMV5...
19 Addendum 4: LMV52... with O2 trim control and O2 module
content (20.9 %)
2
Content Air
Ctrl/Guard»:
2
-guard / O -control /
2 2
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