Electrical installer
32
4
Figure 4.3
Connection of request signal to OCDS007 chronothermostat
Figure 4.4
Connection of alarm indication signal to OCDS007
chronothermostat
Figure 4.5
External heating request connection
COM
Common
REQ
Heating request
Components NOT SUPPLIED:
CS
External request
CS
COM
NO
4.4.2
DHW production control systems
4.4.2.1
OQLT021 system controller (optional)
See Paragraph 4.4.1.1
4.4.2.2
External request
See also Paragraph 1.7.2.3
It is required to arrange:
▶
Enable device (e.g. thermostat, timer, switch, ...) fitted with a
voltage-free NO contact.
How to connect the external request
Connection of external request is effected on the termi-
nal block located in the electrical panel inside the unit.
1. Access the electrical board of the appliance according to
the Procedure 4.2
2. Connect the voltage free contact of the external device,
through two conductor wires, to terminals COM and
DHW (respectively: common and DHW request selector)
of the internal terminal block (Figure 4.6
p. 32).
3. Use shielded cable 2x0,75 mm², connecting the shield to
one of the ground terminals provided on the appliance
electrical panel.
4. The connection cable must be kept separate from mains
voltage cables.
The signal is SELV (Safety Extra Low Voltage). The volt-
age-free contact of the external device that gives the
request must have double or reinforced insulation with
respect to line voltage parts.
The cable may not be longer than 30 metres.
Figure 4.6
DHW external request connection
COM
Common
DHW
DHW request selector
Components NOT SUPPLIED:
CS
External request
CS
COM
NO
4.5
DIVERTER VALVE FOR DHW
PRODUCTION
This paragraph is not applicable in case of use of
OQLT021 system controller. If such a controller is used,
follow the instructions for connecting the diverter valve
in the relevant installation manual.
The DHW diverter valve is required if DHW production service
is required.
The DHW diverter valve must be of the type with always present
