Technical information

IFD 258 · Edition 03.08
29
Two-stage burner control with two solenoid 7.15
valves
The IFD is equipped with two signalling contacts for operating
and fault signals. For controlling two-stage burners, a bridge
must be installed in the lower section of the housing between
terminals 12 and 13. Valve V2 is connected to terminal 14.
I
Z
c
PE
max. 2 A,
253 V~
*
1 2 3 4 5 6 7 8 9 10 11 12
230V
L1 (L1)
N (L2)
s1
s2
v2v1
F1
13 14
max.
2 A,
253 V~
IFD 258
Program sequence
t
W
t
1
3
10
11
5
8-9
14
ϑ
L1
t
Z
t
SA
88
04
0201
V1
V2
During the waiting time t
W
after heat demand, checks are
made for flame simulation and faults. If no flame simulation
is detected, the IFD 258 opens the gas valve V1 and ignites
the burner. The ignition time t
Z
is constant. The safety time t
SA
starts with the ignition time t
Z
. If a flame is detected during
the safety time, the fault signalling contact closes. Once the
safety time t
SA
has elapsed, the operation signalling contact
closes and valve V2 is opened.
Example of application
Control: ON/OFF or ON/HIGH/LOW/OFF
The burner BIO/BIC starts at low-fire rate. Once the normal
operating state is reached, the automatic burner control unit
IFD 258 opens the air valve. The burner switches to high-fire
operation.
IFD 258
10
µC
BIO/
BIC
VR..R
11
8
9
13
14
5
GIK..B
VAS
12
Project planning information