Installation guide

28
The boiler is connected to power supply
by a three-core fl exible cord with a plug.
A fi xed socket through which the boiler is
connected to power mains must comply
with the provisions of STN 33 2000-4-46.
This must always have a protective (earth)
contact (pin), reliably connected by a PE
or PEN wire (yellow-and-green). The
boiler must be always connected to the
protection wire (earth) through its power
cord and must be always installed in such
a manner that the socket and plug are
accessible. Use of adapters, extension
cords etc., is not permitted.
Important: Preparation of the socket and
connection of the room control unit, which
requires intervention with the boiler’s
internal wiring, must be always connected
by a qualifi ed electrician in accordance
with Public Notice No. 50/1978. Likewise
servicing of the electro-technical part
must be performed by only a person with
the above qualifi cation. Before performing
any works on the electro-technical part,
the boiler must be disconnected from the
power supply by removing the power cord
plug from the power socket!
The main part of the boiler is secured by a
tube fuse (T1, 6A / 250 V), which is located
on the control panel of the boiler.
For control of the boiler using a room
control room unit only a zero-potential
output room control unit may be used, i.e.
a unit which convey no foreign voltage to
the boiler.
The room control unit must be connected
to the boiler by a two-core cable. The
recommended copper wire cross-section
is 0.5 to 1.5 sq.mm.
The room control unit connection cables
must not run concurrently with power
wires or cables.
The terminal for connection of the room
control units is equipped from the factory
with a jumper and is located in the electrical
box of the boiler. Before connection of the
room regulator it is necessary to remove
the jumper on the terminal. In all other
cases the jumper is left.
If the boiler is to be operated in the
continuous control mode according to
outside temperature, i.e. equithermal
regulation, an outdoor temperature sensor
is attached to it.
This sensor is located outside, preferably
at half the height of the building (or of
the heated zone), at least 2.5 m above
the ground. If equithermal regulation is
predominantly intended to control heating
according to the required comfortable
temperature, the sensor is placed on the
same side of the building as the windows
of the heated rooms – if this cannot be
secured then it is placed on the north-
western side. If equithermal regulation is
predominantly intended to optimise the
quantity of heat, the sensor is always
placed on the coldest (most often north)
side of the building.
The sensor is connected to the boiler by
a two-core cable with a cross-section of
(copper) conductors of at least 0.5 sq.mm
and a length of maximum 30 m (between
boiler and sensor, i.e. total 60 m of
conductor measured from boiler to sensor
and back to boiler). This cable must not run
concurrently with other electrical wiring
and areas with more powerful electrical
machinery (e.g. welding machines).
Electrical connection of boiler