Accessing The X3 Plug; Connecting The Outdoor Temperature Sensor - Viessmann VITOCROSSAL 300 Installation Instructions Manual

Vitocrossal 300 CU3A 26 to 57 Installation

Accessing the X3 Plug

Connecting the Outdoor Temperature Sensor

1. Remove the X3 plug from the control board. Attach
sensors and reinsert the X3 plug. Refer to the
following sensor information.
2. Reinstall the control cover.
1. Remove cover of outdoor temperature sensor.
2. Mount wall-mount base (cable entry must point
downward).
IMPORTANT
The outdoor temperature sensor should be mounted 6.6
to 8.2 ft. (2 to 2.5 m) above ground level on the north or
northwest wall of the building. In case of a multi-storey
building, mount outdoor temperature sensor in the upper
half of the second floor.
Ensure that sensor is not located above windows, doors
and air vents, or immediately underneath a balcony or
gutter.
The outdoor temperature sensor must not be covered
by plaster. If mounting on an unplastered wall, make
allowances for thickness of plaster or remove sensor
before plastering wall.
3. Route cable from the boiler control board to the
outdoor sensor. Connect cable to sensor terminals
(wires are interchangeable).
Cable specifications:
2-wire cable, max. cable length 115 ft. (35 m) with a
wire size of min. AWG 16 copper.
4. Connect the outdoor temperature sensor to terminals
X 3.1/X3.2 on the boiler control board (wires are
interchangeable).
IMPORTANT
Cable to the outdoor sensor must not be laid near line
voltage wiring (120/240V).
Control Connections
27