Technical data

Safety
6
Installation instructions VRC 470 0020116690_00
2
Protecting against Legionella
The controller is furnished with an anti-Legionella func-
tion to protect against infection by germs (Legionella).
When the function is activated, the water in the domes-
tic hot water cylinder is heated to over 60 °C for at least
one hour.
> Set the anti-Legionella function when installing the
controller.
> Explain to the operator how the anti-Legionella func-
tion works.
Preventing the risk of scalding
There is a danger of scalding at the hot water draw-off
points if the temperatures are greater than 60 °C. Young
children and elderly persons are particularly at risk,
even at lower temperatures.
> Select a moderate target temperature.
> Inform the owner about the risk of scalding when the
anti-Legionella function is switched on.
Protecting the controller from damage
> The controller should only be installed in dry rooms.
Preventing malfunction
> Ensure that the heating system is in a technically per-
fect condition.
> Ensure that no safety or monitoring devices have
been removed, bridged or disabled.
> Immediately rectify any faults and damage that may
negatively affect safety.
> Inform the operator that he must not cover the con-
troller with furniture, curtains or other objects.
> Inform the operator that the radiator valves in the
room where the controller is installed must be turned
fully open.
> If thermostatic control is activated, advise the opera-
tor that, in the room where the controller is mounted,
all the radiator valves must be fully open.
2.4 Requirements for cables
> Use standard commercial cables for wiring.
Minimum cross-section of the cable:
– Supply cable 230 V (pumps or mixer supply cable):
1.5mm
2
– Low-voltage conductors(sensor or bus lines):
0.75mm
2
Maximum cable length:
– Sensor lines: 50 m
– Bus lines: 300 m
> At lengths of over 10 m, 230V supply cables must be
laid separately from sensor or bus lines.
> Fasten the supply cables using the strain relief device
in the wall mount.
> Do not use the free terminals in the unit as supports
for other wiring.
> The controller should only be installed in dry rooms.
2.5 Directives, laws and standards
All wiring must be in accordance with Building Regula-
tions Part P and BS 7671 (IEE Wiring Regulations), and
must be carried out by a suitably qualified person.