28
8.1 EXTERNAL WIRING
The appliance comes with a factory fi tted (TA) link to
allow basic operation of the boiler via the mode selector
switch. If external controls are to be added to the system,
they must be connected to the appliance as shown in the
following diagrams. For advice on controls that are not
featured in this book, please contact Vokera technical
0844 391 0999
.
NOTE
●
THE LINK WIRE MUST BE REMOVED IF ADDI-
TIONAL CONTROLS ARE ADDED
●
THE ELECTRICAL SUPPLY TO THE PUMP MUST
BE CONNECTED TO THE TERMINALS AS SHOWN
IN FIG. 31
●
A PERMANENT 230V SUPPLY MUST BE CON-
NECTED TO THE BOILER AS SHOWN IN FIG. 31
8.1.1 EXTERNAL WIRING LIMITATIONS
Any external wiring must remain within the limits as de-
tailed in the table below.
CONNECTION
MAX. LENGTH
Room thermostat
30-metres
Time clock
30-metres
Programmer
30-metres
8.2 TYPICAL CONTROL APPLICATIONS
The appliance can be used with the following controls:
Single-channel, voltage-free time clocks.
Programmable room thermostats.
External twin-channel programmers. The appliance can
be used in conjunction with typical ‘S’-Plan/’Y’-Plan
systems (see 8.4.1 & 8.4.2), please contact Vokera
technical should you require further detailed instruction.
8.3 OTHER DEVICES
Contact the controls manufacturer and/or Vokera technical
department should you require more specifi c information
on the suitability of a particular control. Further guidance
on the recommended practice for the installation of exter-
nal controls, can be found in CHeSS – HC5/HC6 (www.
energyeffi ciency.gov.uk).
SECTION 8 WIRING DIAGRAMS
IMPORTANT
●
The boiler must always be supplied with a permanent
230V electrical supply.
●
The pump must always be connected directly to the
pump terminals located within the boiler.
●
Always remove the link between TA & TA on the ap-
pliance high-voltage terminal strip whenever additional
controls are connected to the appliance.
Fig. 38
