Supplied By www.heating spares.co Tel. 0161 620 6677
27
8.1
EXTERNAL WIRING
The appliance comes with a factory fitted (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 on 0870 333 0520.
8.1.1
EXTERNAL WIRING LIMITATIONS
Any external wiring must remain within the limits
as detailed in the table below
8.2
TYPICAL CONTROL APPLICATIONS
The appliance can be used with the following
controls:
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single-channel, voltage-free time clocks (fig. 34a)
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programmable room thermostats (fig. 34b)
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twin-channel programmers (figs 39 & 40). 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
Although it’s permissible to use/connect certain
OT+ (Opentherm Plus) controls or the Vokera
external sensor, you should ensure that these
controls do not inhibit or limit the response to any
heat request from a DHW cylinder.
Contact the controls manufacturer and/or Vokera
technical department should you require more
specific information on the suitability of a particular
control. Further guidance on the recommended
practice for the installation of external controls,
can be found in CHeSS – HC5/HC6
(www.energyefficiency.gov.uk).
SECTION 8
WIRING DIAGRAMS
CONNECTION
MAX. LENGTH
External sensor
30-metres
Room thermostat
30-metres
OT+ connection
30-metres
Fig. 34a
Fig. 35
U.H.T. = underfloor heating thermostat
C.P.A.= condensate pump alarm
E.S.=
external sensor
OT+=
ope connection
OPTIONAL DEVICE (24V) TERMINAL BLOCK
8.4
VOKERA TWIN-CHANNEL PROGRAMMER
(code 514)
The Vokera 2-channel programmer kit (product
code 514) has been developed specifically for the
Mynute HE range and eliminates the need for an
external programmer.
The kit is comprised of the following:
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2-channel programmer
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24V wiring harness
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230V wiring harness & terminal strip
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instructions.
Isolate the appliance from the electrical supply;
unhook and remove the control PCB cover.
Remove the clock blanking disc from the clock
aperture on the boiler. Secure the programmer to
the clock aperture using the screws previously
removed.
Fig. 34b