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Function
Control sequence
AC 220...240 V
AC 100...110 V
t1
Prepurge time
t3
Preignition time
t3´
Preignition time from start of «TSA»
TSA
Ignition safety time
TSAmax.
Max. ignition safety time
t3n
Postignition time
t4
Interval «BV1 – BV2»
Control sequence in the
event of fault
Fault
Erroneous flame signal during «t1»
or «t3»
No flame on completion of «TSA»
Loss of flame during operation
No air pressure signal during «t1»
Air pressure failure during operation
Flame supervision with
ionization probe
Siemens Building Technologies
HVAC Products
(times in seconds)
1
)
LGA41.153A27
---
---
15
---
5
10
max. 2
approx. 18
¹)
All times specified apply to AC 220 V and AC 110 V respectively
For AC 240 V operation, above times are to be multiplied by 0.7
Response of LGA41...
Lockout ²) prior to the release of gas Lockout ²) prior to ignition and the re-
Lockout ²)
Repetition
²)
After lockout, the burner control can be reset after about 60...90 seconds
The conductivity and rectifying effect of hot flame gases are used for flame supervision.
For that purpose, AC voltage is applied to the ionization probe which projects into the
flame.
The current that flows in the presence of a flame (ionization current) generates the
flame signal which is then fed to the input of the flame signal amplifier.
The amplifier is designed such that it only responds to the DC current component of the
flame signal, thus ensuring that a short-circuit between ionization probe and ground
cannot simulate a flame signal (since in that case, AC current would flow).
LGA41.173A27
LGA52.150B27
---
LGA52.150B17
---
approx. 13
15
---
---
max. 5
10
5
20
10
max. 2
---
approx. 13
approx. 18
Response of LGA52... / LGA63...
lease of gas
Lockout ²)
Repetition
---
No start
---
Shutdown
LGA52.171B27
LGA63.191A27
---
---
approx. 13
approx. 13
---
---
4.5...7.5
max. 10
4.5...7.5
10
20
20
---
---
approx. 13
approx. 23
CC1N7418en
08.04.2004
7/11
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