7
SYSTEM DESIGN
WIRING THE SYSTEM
The whole of the electrical installation shall be designed
by a competent person fully in accordance with the latest
edition of the Requirements for Electrical Installations
BS 7671.
However, the following guidance is provided to show the
general principles involved.
The PulsaCoil III appliance is provided with two side
entry immersion heaters. The lower element is connected
to the off peak supply and enables the whole of the
contents to be heated overnight using a low cost tariff.
The upper element is connected to the unrestricted sup-
ply and enables the upper part of the contents to be given
a day time boost. This is switched manually or by a
timer and uses the standard tariff. In some areas the
local electricity company allows a limited day time off
peak boost.
It is normal to supply the PulsaCoil III using an Ecomony
7 controller as shown in Figure 2.2.
Alternatively the PulsaCoil III can be supplied from
separate circuits as shown in Figure 2.3. In this case the
two switches should be clearly labelled for the
householders use.
Fig 2.1 Schematic layout of typical domestic hot & cold water systems.
In addition to the supplies to the immersion heaters,
PulsaCoil III requires a 3 amp supply for the control
circuit. This 3 amp supply must be provided via a fused
3 amp double pole isolator providing 3mm of separation
to both poles.
Plastic Pipework
This appliance is suitable for use with plastic pipework
as long as the material is recommended for the
purpose by the manufacturer and is installed fully in
accordance with their recommendations.
We recommend the use of barrier pipe, which will
mean the system can have BritishGas service cover
in regions offering this service.
