Application examples
The suitable wiring schemes are merely examples which must be verified in the individual case depending on
application!
Control of actuators of 2-stage or 2-stage modulating
burners. Controlled prepurging «t1» with low-fire air
volume. Same low-fire actuator position 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
LME21...
12
2
10
8
3
6
EK2
LP
M
AL
HS
N
1
2
0 I
Si
b1
b2
N L
III
a
b
a3
II
I
MS
a b
a b
SQN3...121... / 2-stage control
* Note
With 2-stage modulating burners (with gas regulation
damper «RV»), «BV2» and the dotted connection be-
tween terminals (*) are not required.
LME21...
12
2
10
8
EK2
AL
HS
N
8
4
0
I
Si
N
L
a1
A
B
SQN7...244 / 2-stage control
18/25
Building Technologies
HVAC Products
11
9
7
4
5
1
(*)
ION
Z
BV1
GP/SB
LR
R/W
BV2
(*)
*
6
7
5
4
3
B
IV
a
b
A
RV
a2
V
a b
LK
3
6
11
7
4
5
LP
Z
GP/
M
SB
BV1
LR
R/W
BV2
1
5
3
2
7
6
b2
c1
b1
a2
C
M
I
II
III
IV
HS
0 I
N L
LKP
t1
I
NL
IV
IV
KL
IV
III
III
Zu
t
II
SA
1
ION
LKP
I
I
NL
IV
IV
III
KL
III
zu
II
t1
TSA
t4
5
12
4
7101a09/0705
LR
SA
SB/R/W
BV1
L
LME21...
10
6
11
12
2
8
3
9
EK2
LP
M
AL
GP/
SB
R/W
N
N
1
2
Si
K2
+
IV
b
a
D
-
+
C3
II
I
MS
a b
a b
SQN91.140... / 2-stage control
t
RV
BV2
4
7
5
1
ION
Z
BV1
LR
BV2
5
3
6
4
III
a b
K1
C31
V
R1
R32
a
b
LK
CC1N7101en
27.11.2008