Power Supply To The System; Routing Connecting Cables/Leads; Checking The Can Bus Terminator Switch Setting - Viessmann Vitovalor PT2 Installation And Service Instructions For Contractors

Installation sequence
Electrical connections
If the current flowing to the connected working parts
(e.g. circulation pumps) is higher than the fuse rating
of the relevant accessory, only use the output con-
cerned to control an on-site relay.

Power supply to the system

Connect the power supply to the system according to
the operating mode selected during preparations for
installation; see page 17.
1. Route the power cable out of the gas condensing
and fuel cell module towards the rear.
2. Connect the power supply to the system for the
selected operating mode and with appropriate pro-
tection. See chapter "Preparing for installation" on
page 17.
Select cable cross-sections in accordance with
applicable VDE [IEE or local] regulations.
Ensure the low resistance of the earth connection.
Danger
Incorrectly executed electrical installations
can result in injuries from electrical current
and damage to the appliance.
Connect the power supply and implement all
safety measures (e.g. RCD circuit) in
accordance with the following regulations:
■ VDE regulations
■ Connection conditions of the local power
supply utility
Install an isolator in the power cable to provide
omnipolar separation from the mains for all active
conductors, corresponding to overvoltage cate-
gory III (3 mm) for complete isolation. The ON/OFF
switches integrated into the Vitovalor PT2 fulfil this
function.

Routing connecting cables/leads

!
Please note
If connecting cables/leads come into contact
with hot components, they will be damaged.
When routing and securing cables/leads on site,
ensure that the maximum permissible tempera-
ture for these is not exceeded.

Checking the CAN bus terminator switch setting

The CAN bus resistor is switched using switch
the wiring chamber.
48
(cont.)
in
A
PlusBus system length max. 50 m for 0.34 mm
cross-section and unshielded cable.
3. Bundle 230 V cables and LV leads separately.
Danger
The absence of system component earthing can
lead to serious injury from electric current if an
electrical fault occurs.
The appliance and pipework must be connected
to the equipotential bonding of the building.
Note
If fault messages occur: See page 115.
2
cable