Technical data

Installation
52
Burner Connection, Burner Control Wiring (VD2/VD2A/CT3 only) (continued)
Write the terminal numbers or
m
arkings on the drawing for future
reference.
Burner power supply not shown.
A Control unit
(Legend: see wiring diagram)
B 2nd stage or modulating *
1
C Hours counter, stage 1 *
1
D Burner fault indicator *
1
E Control circuit, stage 1/
basic load *
1
F Burner
fÖ Power supply connection of control
unit 120 VAC
fA Burner, 1st stage
lÖ Burner, 2nd stage
aBÖ Plugs for external equipment
a External safety devices
(remove jumper when connecting)
b External controlled switch-off
(remove jumper when connecting)
aBA Safety circuit. Emergency
shut-off
*
1
Refer to burner manufacturer’s instruction on detailed connections for Viessmann controls.
5285 941 v1.5
This is a generic connection drawing
only! Follow the burner
manufacturer’s connection drawings
for Viessmann controls.
CAUTION
a b
Plug connection
located on the
DIN rail.