IDEAL EVOMOD 250 - Electrical Connections

22 EXTERNAL WIRING
External wiring MUST be in accordance with the current I.E.E.
(BS7671) Wiring Regulations. For Ireland reference should be
made to the current ETCI rules for electrical installations.
For wiring external controls to the boiler, reference should be made
to the systems wiring diagram supplied by the relevant manufacturer
in conjunction with the connection diagram shown in Frame 25
.
Difculty in wiring should not arise, providing the following
directions are observed:
A wiring tray has been provided to allow the safe routing of
all external wires within the master boiler module. All cables
should be secured using the cable glands provided at the
rear entry holes on the Installer Wiring Box. Cables should be
passed through the grommets in either the 16mm or 22mm
wiring access holes in the rear panel (see Frame 24).
1. The appliance must be wired with a permanent live supply.
External controls should NOT be wired in series with this
mains input. Controlling the mains input in this way will
prevent the pump over-run sequence and may cause
damage to the heat exchanger.
2. Connection of Header Pump A single Cascade/System
pump may be connected to the Master PCB via an
external contact or relay. This pump is controlled from the
Sequencer and runs whenever any module is active, also
providing pump overrun. This output may also be used to
provide pump overrun requirements to a BMS or control
panel where multiple pumps or zones are installed.
3. Connection of Optional Module Pumps Module pumps
may be connected directly to the Boiler via the Installer
Wiring Box, providing that their individual load does not
exceed 3A inductive.
Each module has a volts free contact allowing control of
the pump independently. This may be wired as a switched
contact with external live feed connected to the pump, or a
common live within the Installer Wiring Box may be linked
to the Live In terminal. The Live In or Live Out terminals
may be commonised using a suitable DIN rail terminal
linking bar if desired.
Note. The circuit protective device, isolation switch and
wiring must be sized in accordance with the total load of
both the boiler and module pumps.
4. Connection of System Controls Connection is provided
within the Master PCB for heating demand. External
wiring into the Master PCB must be strain relieved by tting
the appropriate bridge clamps into the plastic base and
securely tightening the screws.
Heating Demand can be controlled in one of two ways:
1. A switched live or volts free contact wired into the screw
terminals L and SL.
2. A 0-10V DC signal via suitable screened 2 core cable into
the screw terminals S and 0V.
Note. The 0-10V input is a safety extra low voltage (SELV)
connection.
Heating demand can be controlled by:
1. ON/OFF using a 230V switched live to 'SL' terminals.
A call for heat will cause the boiler to run and maintain a set
ow temperature (see Frame 25).
2. 0-10V (SELV)
A call for heat can be generated using a 0-10V input with
the ow temperature set point or boiler capacity controlled
by the voltage signal.
Connect 0-10V signal using terminals marked '0-10V'.
Header Thermistor (provided with Lead and Cable Gland)
A Header Thermistor is provided to monitor the desired set point
temperature to control the boiler output. This can be placed in
the supplied header or at an appropriate point in the system pipe
work. It must not be extended past the supplied cable length.
Boiler Status Signals
Two volts free contacts are provided to indicate the status of the
boiler to remote system controls. A Burner On contact is closed
when any of the boiler modules is ring. The Fault contact is
closed 4 minutes after a boiler or module fault occurs.
23 CH CONTROL CONNECTIONS
24 CABLE ROUTING
Installer Wiring Box
Wiring Tray
22 mm Access Hole
Rear panel
16 mm Access Hole
Note: Please ensure SELV separation when using single wires
INSTALLATION
22
- Installation & Servicing
INSTALLATION