Connection Diagrams - Siemens LGB21.130A17 Datasheet

Connection diagrams

LGB21...
Burner controls for 1- or 2-stage forced draft burners.
Air damper control for prepurging with low-fire air volume.
A
GP/SB
R/W
tw
M
t10
LP
Z
BV1
BV2
FS
7435f01/1299
Application examples
Control of actuators of 2-stage or 2-stage modulating burners.
Prepurging («t1») with low-fire air volume.
Same low-fire actuator position (switching cam III) during startup and
operation!
For information about actuators «SA»:
SQN3...: Refer to Data Sheet N7808
SQN7...: Refer to Data Sheet N7804
SQN9...: Refer to Data Sheet N7806
12 2 10 8 3
EK2
M
AL
SB
N 1 2
HS
b2
b1
0 I
III
N L
a b
a3
II
MS
a b
SA
SQN3...121...
* Note:
With 2-stage modulating burners (with gas control damper «RV»),
«BV2» and the dotted connection between terminals (*) are not
required
14/22
Building Technologies
HVAC Products
B B´ C
t1
t3
t4
TSA
6 11 5
9 7 4
(*)
Dbr1
LP
Z
BV1
GP
R/W LR
BV2
(*)
7 5 4 3
6
B
IV
a b
A
a2 a1
I
V
a b a b
Flame supervision
LGB21...: With ionization probe or auxiliary unit AGQ1...A27 for UV detector
QRA...
D
12 12 2 10
3 GP/SB
6
W
11
AL
7
EK2
R
HS
4
0 I
5
L
N
1
LGB2...
LR
SA
BV1
1
12
ION
SB
*
N
HS
0 I
N L
RV
LK
SA
8 3 6 11 7 9 4
Dbr1
bv1
bv2
BV1
Z
M
LP
LKP
t1
NL
RV
IV
KL IV
III
Zu
II
2 10 8 3 6 11 9
Dbr1
EK2
LP
M
AL
GP
R/W
N
1 2 5
K2
+
IV
a b a b
D
- +
C3
C31
II
I
MS
R32
a b a b
SQN91.140... / 2-stage control
5 1
ION
BV2
I
IV
III
t
7 4 5 1
ION
Z
BV1
LR
BV2
3 6 4
III
K1
V
R1
a b
LK
7435a02/0704
CC1N7435en
11.01.2007