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Building Technologies
Basic Documentation LMV27...
CC1P7541en
7 Basic unit LMV27
17.12.2018
7.5.3.11. Test function for approval of burner – loss-of-flame
test (TÜV test)
The purpose of this test is to verify the detection time required in the event of loss of
flame when applying for burner approval. When starting the test, the fuel valves are shut
to determine the time (resolution of 0.2 seconds) until the LMV27 detects loss of flame.
Procedure:
Determine the burner output at which the test shall be made, using parameter 133.
If these parameters are not set, the test is carried out at the current output of the
system
Start the test by entering value 1 for parameter 124.
If the burner’s output was defined for the test (parameter 133), the LMV27 runs to
that output first. To implement this function, the default value of parameter 121
(manual output) is used. This cancels any manual output that was previously active
Now, the LMV27 shuts the fuel valves, leading to loss of flame
The evaluation is made by the LMV27 by measuring the time the system requires
from fuel valve shutdown until loss of flame is detected.
Then, the required time is displayed in the form of diagnostic code
C:7
(loss of
flame)
The resolution is 0.2 seconds.
Example
When the display reads
C:7 D:10
, the time required from valve shutdown to
detection of loss of flame is 2 seconds (
D:10
means 10 x 0.2 = 2 seconds).
When the test is successfully completed, parameter 124 is reset to
0
. If unsuccessful, a
negative value is delivered for diagnostic purposes and error code
150
is entered.
-1 = invalid phase (test only possible in phase 60) – display reads
C:150 D: 1
-2 = default output < minimum output – display reads
C:150 D:2
-3 = default output > maximum output – display reads
C:150 D:3
-4 = manual abortion (no error, start variable was manually reset to
0
) – display reads
C:150 D:4
-5 = timeout during TÜV test (no loss of flame after shutdown of valves within
50
seconds) – lockout
C:150 D:5
Previously set output values at which the test shall be made (parameter 133) remain
stored.
No. Parameter
121
Manual output
Undefined = automatic operation
124
Loss of flame test (TÜV test) starting (parameterized on 1)
(switch off the fuel valves
loss of flame)
Error diagnostic via negative value (refer to error code 150)
133
Default output at TÜV test
Invalid = TÜV test at active output
20...100 = low-fire...high-fire or stage 1 / stage 2 / stage 3
P1...P3 = stage 1...stage 3
