Mains Supply; Electrical Supply; Equipotential (Earth) Bonding; Gas Supply - Worcester GREENSTAR 24i Junior Installation Instructions Manual

PRE-INSTALLATION
3.2

MAINS SUPPLY

3.2.1

ELECTRICAL SUPPLY

• Supply: 230V - 50 Hz, 140 Watts
• Cable: PVC insulated 0.75 mm
temperature rated to 90 °C.
• External 3A fuse to BS1362.
• The appliance must be earthed.
• This appliance must not be connected to a three
phase supply.
• IPX4D.
NOTICE: This is reduced to IP20 if the
following mechanical timers are fitted;
7 716 192 036 or 7 716 192 037
• Wiring must comply with the latest IEE wiring
regulations.
3.2.2 EQUIPOTENTIAL BONDING
MAIN EQUIPOTENTIAL BONDING
Main equipotential bonding is carried at the origin of the
electrical installation and connected to the main
electrical earthing terminal.
Metal pipes can be used as bonding conductors if joints
are metal to metal and electrically continuous.
The IEE Wiring Regulations (BS 7671:2008) require that
extraneous conductive parts must be connected to the
main electrical earth.
The main bonding of incoming metallic services must be
as close as practical to their entry point, before any
branch pipe work and a maximum of 600mm from an
internal meter.
Bonding conductors must be copper and the same size
as other bonding conductors and not less than 10mm
The bonding conductors must be permanently fixed to
the metal pipes with clamps and labels (to BS 951) in a
visible position to allow for inspection.
SUPPLEMENTARY BONDING
Supplementary bonding is normally carried out in an
area of increased shock risk e.g. bathrooms.
Consult a qualified electrician for them to determine if
the installation requires supplementary bonding as
specified in the 17th edition of the IEE Wiring
regulations (BS 7671:2008).
3.2.3

GAS SUPPLY

• Boilers using Natural Gas (NG) must be connected to
a governed meter.
• Liquid Petroleum Gas (LPG) must be connected to a
regulator.
• Installation and connection of the gas supply to the
boiler must be in accordance with BS6891.
• Under no circumstance should be size of the gas
supply pipe be less than 22 mm.
• The meter or regulator and pipe work to the meter
must be checked, preferably by the gas supplier.
This is to ensure that the equipment is in good
working order and can meet the gas flow and
pressure requirements, in addition to the demand
from any other appliance being served.
12
2
(24 x 0.2 mm)
2
.
3.2.4

WATER SUPPLY

WATER MAINS PRESSURE:
• Minimum mains water pressure: 1.3 bar for 24 and 28i
Junior, for maximum performance.
• Maximum mains fed water pressure 10 bar.
If necessary fit a pressure reducing valve.
NOTICE: Non return, flow back prevention
devices (including those associated with
water meters) fitted to the mains water
supply can cause a pressure build up which
could damage the boiler and other
household appliances.
• Where the mains water supply has a non-return, flow
back prevention valve fitted, a mini expansion vessel
(1) should be connected to the mains water inlet pipe
(2) between the non-return valve (3) and the boiler
(4) as shown below.
1
2 3
1 Mini expansion vessel - part no. 7 716 102 105
2 Mains water inlet pipe
3 Non return valve
4 Boiler
USE IN HARD WATER AREAS:
Normally there is no need for water treatment to prevent
scale formation as the maximum temperature of the HW
heat exchanger is limited by the electronic control.
In areas where temporary water hardness exceeds
200 ppm, consideration may need to be given to the
fitting of a scale prevention device. In such
circumstances, the advice of the local water authority
should be sought.
6 720 644 741a (2010/10)
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6720643895-04.1Wo