Instruction manual DXB heater
page 8
22°C
Thermostat
230V
24V
K2
5
6
TR2
F3
T0,05A
5
1
Thermostat relay
4.3 Electricity supply
4.3.1 230Vac supply
The installation must comply with local and national requirements, (as well as IEE regulations).
The unit heater is delivered completely internally wired. Where controls of any type are to be
added (e.g. room thermostat), the relevant wiring diagrams must be followed. Never use a room
thermostat to interrupt the electrical supply to the heater!
The supply is 230Vac 50Hz with earth. When the supply voltage is lower than 195V and higher
than 255V the correct functioning of the heater is not guarantied.
A mains cable including plug is supplied with the heater. The wires of the cable must
be connected to the clamps in the connection box. Make sure you do not damage the mains
cable. Replace a damaged cable immediately.
When the heater is connected without a plug, make provisions to completely isolate the heater
for maintenance purposes. This can be an isolation switch (min. 3mm contact opening gap).
The switch should not interrupt earth.
Ensure the plug or switch is located within a 2 m radius of the heater and the plug can be
removed easily and quickly from the socket
4.3.2 Thermostat connection
The heater can be controlled in 2 ways.
1.
Controlled by an ON / OFF signal
2.
controlled trough a bus system by an external interface.
4.3.3 Thermostat cable
Always use for the thermostat the right cable.
Cable specification: signal cable, 1x2x0,8 (shielded and twisted)
Maximum length 200m.
If the cable is too thin, the signal will be too weak and heater will not work. If the cable is not
shielded and twisted the signal might become disturbed in an EMC unfriendly environment.
Keep the thermostat cable separated from mains cables. Connect the earth shield of the cable
only to the earth terminal in the heater.
If these guidelines are not followed it may result in malfunction of the installation or worse, it
could damage the thermostat or the electronics in the heater.
4.3.4 ON / OFF thermostat signal
(standard configuration see wiring diagram P002 )
The heater has an 24V thermostat circuit. When the contact between the clamps 5 and 6 are
closed the heater will start.
Every heater has to be switched by a
separate
low voltage ON/OFF contact
in the control room
Do not connect more than 1 hater under 1 contact.
