Electrical Connections To The Power / Pump Module; Optional Operating Control - Open Therm - Viessmann VITODENS 100-W WB1B Series Installation And Service Instructions Manual

Control Connections
Electrical Connections
Electrical connections to the power pump module (room thermostat and DHW)
120V PUMP
Fig. 38
Legend
A Main power supply
(120V, 60Hz, 1 PH).
B Heating circuit pump (or boiler
pump for low-loss header
application).
C DHW tank temperature controller /
external heat demand
(field supplied)
D Room temperature thermostat
(Anticipator setting 0.2A)
(field supplied)

Optional operating control - Open Therm

OT
Fig. 39
38
(continued)
IMPORTANT
Remove short factory test leads from
terminal L, N and Ground before
connecting main power supply to
boiler A.
IMPORTANT
Ensure that pressure activated
by-pass is installed with system
layout 1 on page 28.
GAS PUMP FAN
Note:
Boilers are factory shipped with a
wiring diagram (11"x17" sheet inside
a pouch) attached to the inside of
the front cover. The wiring diagram
shipped with the boiler supercedes the
DHW RT
wiring information in this manual.
Provide a main power disconnect /
service switch as per local code
requirements. Also refer to wiring
diagram on page 79.
What is OpenTherm?
The OpenTherm (OT) protocol is a
point-to-point communication system,
which connects a boiler with a room
controller or other devices. The room
unit calculates a heating demand
(water temperature request) and
transmits it to the boiler. The boiler
will adjust the heat input accordingly
(low-high modulation).
Legend
A 0-10 V (field wiring)
B Viessmann outdoor temperature
sensor (field wiring)
C Open Therm (field wiring)
D Connection cable terminal
E Power pump module
% Plug-in connection cable box.
See wiring diagram on page 79.
Follow the installation instructions of
the field supplied operating controls.