Forte
Table B
Note:
Cable selection is dependent on
derating factors
Twin and earth PVC insulated cable
Current carrying capacity
In conduit
trunking
6 mm²
38A
10 mm²
52A
16 mm²
69A
Installed in an
insulated wall
6 mm²
32A
10 mm²
43A
16 mm²
57A
Clipped direct
or buried in a
non-insulated
wall
6 mm²
46A
10 mm²
63A
16 mm²
85A
The installation, supply cable and circuit
protection must conform with BS 7671 (IEE
wiring regulations) and be sufficient for the
amperage required.
The following notes are for guidance only:
1
1.1
2
3
3.1
4
4.1
4.2
5
5.1
6
6.1
7
7.1
7.2
8
9
9.1
9.2
10
10.1
10.2
10.3
E-002-A
The shower must only be connected to a
230-240V ac supply. If you are installing a
shower with a kilowatt rating above 9kW,
it is advisable to contact the local
electricity supply company.
The electrical rating of the shower is
shown on the rating label
(Fig. )
within
the unit.
Before making any sort of electrical
connection within the installation make
sure that no terminal is live. If in any
doubt, switch off the whole installation at
the mains supply and remove the correct
fuse.
The shower must be connected to its own
independent electrical circuit. IT MUST
NOT be connected to a ring main, spur,
socket outlet, lighting circuit or cooker
circuit.
The electrical supply must be adequate for
the loading of the unit and existing
circuits.
Check your consumer unit (main fuse box)
has a main switch rating of 80A or above
and that it has a spare fuse way which will
take the fuse or Miniature Circuit Breaker
(MCB) necessary for the shower
(Fig. )
.
If your consumer unit has a rating below
80A or if there is no spare fuse way, then
the installation will not be straightforward
and may require a new consumer unit
serving the house or just the shower.
You will need to contact the local
electricity company. They will check the
supply and carry out what is necessary.
They will also check the main bonding.
The earth continuity conductor of the
electrical installation must be effectively
connected electrically to all exposed metal
parts of other appliances and services in
the room in which the shower is to be
installed, to conform to current IEE
regulations.
All exposed metallic parts in the bathroom
must be bonded together using a cable of
at least 4 mm² cross sectional area. These
parts include metal baths, radiators, water
pipes, taps and waste fittings.
For close circuit protection DO NOT use a
rewireable fuse. Instead use a suitably
rated Miniature Circuit Breaker (MCB) or
cartridge fuse
(see Table A)
.
In the interest of electrical safety a 30mA
residual current device (RCD) should be
installed in all UK electric and pumped
shower circuits. This may be part of the
consumer unit or a separate unit.
A 45 amp double pole isolating switch
with a minimum contact gap of 3 mm in
both poles must be incorporated in the
circuit.
It must have a mechanical indicator
showing when the switch is in the OFF
position, and the wiring must be
connected to the switch without the use of
a plug or socket outlet.
The switch must be accessible and clearly
identifiable, but out of reach of a person
using a fixed bath or shower, except for
the cord of a cord operated switch, and
should be placed so that it is not possible
to touch the switch body while standing in
a bath or shower cubicle. It should be
readily accessible to switch off after using
the shower.
Where shower cubicles are located in any
rooms other than bathrooms, all socket
outlets in those rooms must be protected
by a 30mA RCD.
The current carrying capacity of the cable
must be at least that of the shower circuit
protection
(see Table B)
.
To obtain full advantage of the power
provided by the shower, use the shortest
cable route possible from the consumer
unit to the shower.
It is also necessary to satisfy the
disconnection time and thermal
constraints which means that for any given
combination of current demand, voltage
drop and cable size, there is a maximum
permissible circuit length.
The shower circuit should be separated
from other circuits by at least twice the
diameter of the cable or conduit.
The current rating will be reduced if the
cabling is bunched with others,
surrounded by thermal loft or wall
insulation or placed in areas where the
ambient temperature is above 30°C. Under
these conditions, derating factors apply
and it is necessary to select a larger cable
size.
In the majority of installations, the cable
will unavoidably be placed in one or
more of the above conditions. This
being so, it is strongly recommended to
use a minimum of 10 mm cabling
throughout the shower installation.
In any event, it is essential that individual
site conditions are assessed by a
competent electrician in order to
determine the correct cable size and
permissible circuit length.
ELECTRICAL REQUIREMENTS
The installation, supply cable and circuit
protection must conform with BS 7671 (IEE
wiring regulations) and be sufficient for the
amperage required.
The following notes are for guidance only:
1
1.1
2
3
3.1
4
4.1
4.2
5
5.1
6
6.1
7
7.1
7.2
8
9
9.1
9.2
10
10.1
10.2
10.3
E-002-A
The shower must only be connected to a
230-240V ac supply. If you are installing a
shower with a kilowatt rating above 9kW,
it is advisable to contact the local
electricity supply company.
The electrical rating of the shower is
shown on the rating label
(Fig. )
within
the unit.
Before making any sort of electrical
connection within the installation make
sure that no terminal is live. If in any
doubt, switch off the whole installation at
the mains supply and remove the correct
fuse.
The shower must be connected to its own
independent electrical circuit. IT MUST
NOT be connected to a ring main, spur,
socket outlet, lighting circuit or cooker
circuit.
The electrical supply must be adequate for
the loading of the unit and existing
circuits.
Check your consumer unit (main fuse box)
has a main switch rating of 80A or above
and that it has a spare fuse way which will
take the fuse or Miniature Circuit Breaker
(MCB) necessary for the shower
(Fig. )
.
If your consumer unit has a rating below
80A or if there is no spare fuse way, then
the installation will not be straightforward
and may require a new consumer unit
serving the house or just the shower.
You will need to contact the local
electricity company. They will check the
supply and carry out what is necessary.
They will also check the main bonding.
The earth continuity conductor of the
electrical installation must be effectively
connected electrically to all exposed metal
parts of other appliances and services in
the room in which the shower is to be
installed, to conform to current IEE
regulations.
All exposed metallic parts in the bathroom
must be bonded together using a cable of
at least 4 mm² cross sectional area. These
parts include metal baths, radiators, water
pipes, taps and waste fittings.
For close circuit protection DO NOT use a
rewireable fuse. Instead use a suitably
rated Miniature Circuit Breaker (MCB) or
cartridge fuse
(see Table A)
.
In the interest of electrical safety a 30mA
residual current device (RCD) should be
installed in all UK electric and pumped
shower circuits. This may be part of the
consumer unit or a separate unit.
A 45 amp double pole isolating switch
with a minimum contact gap of 3 mm in
both poles must be incorporated in the
circuit.
It must have a mechanical indicator
showing when the switch is in the OFF
position, and the wiring must be
connected to the switch without the use of
a plug or socket outlet.
The switch must be accessible and clearly
identifiable, but out of reach of a person
using a fixed bath or shower, except for
the cord of a cord operated switch, and
should be placed so that it is not possible
to touch the switch body while standing in
a bath or shower cubicle. It should be
readily accessible to switch off after using
the shower.
Where shower cubicles are located in any
rooms other than bathrooms, all socket
outlets in those rooms must be protected
by a 30mA RCD.
The current carrying capacity of the cable
must be at least that of the shower circuit
protection
(see Table B)
.
To obtain full advantage of the power
provided by the shower, use the shortest
cable route possible from the consumer
unit to the shower.
It is also necessary to satisfy the
disconnection time and thermal
constraints which means that for any given
combination of current demand, voltage
drop and cable size, there is a maximum
permissible circuit length.
The shower circuit should be separated
from other circuits by at least twice the
diameter of the cable or conduit.
The current rating will be reduced if the
cabling is bunched with others,
surrounded by thermal loft or wall
insulation or placed in areas where the
ambient temperature is above 30°C. Under
these conditions, derating factors apply
and it is necessary to select a larger cable
size.
In the majority of installations, the cable
will unavoidably be placed in one or
more of the above conditions. This
being so, it is strongly recommended to
use a minimum of 10 mm cabling
throughout the shower installation.
In any event, it is essential that individual
site conditions are assessed by a
competent electrician in order to
determine the correct cable size and
permissible circuit length.
ELECTRICAL REQUIREMENTS
