Fit an electrical shower unit.
Electric Showers require large amounts of
power (7kW or more) although for a fairly short time. Because of this
they cannot be generally recommended as a viable means of producing hot
water.
There are situations though where they can be considered appropriate,
where there is sufficient power available and other means are awkward
or just not available
There are many types of shower unit available and it is recommended that you follow individual manufacturers' instructions as well as the following steps:
Tools
Pliers, side cutters, lump hammer, screwdrivers, bolster chisel,
multi-meter
Materials
Consumer unit with 30mA rcd and a spare way for a 32A or 40A mcb, double pole
pull-switch
Safety first
Never work on any part of the electrical installation without first
switching off the supply at the consumer unit and, where possible, removing
the circuit fuse. Always unplug any electrical appliance before doing any
work on it. Check all connections are secure and all covers have been replaced
before you turn the electricity on again.
Selecting the power requirements of your shower
Please refer to the table in the package for the representation of
the range of available electric shower units. It indicates the corresponding
size of protective device and appropriate cable cross sections.
Common safety features
If the shower unit is protected by a rewirable fuse, the requirement
for larger cable sizes will add extra cost and there may be some difficulty
in connecting such large cables into the unit. The mcb is the preferred over-current
protective device for these circuits. For protection against earth leakage
currents these circuits also require a 30mA residual current device, (rcd).
Arranging an adequate power supply
The circuit protective device will depend on the rating of the unit. Where
the existing consumer unit does not have a spare way of adequate capacity,
an additional small consumer unit is required. This should include a 30mA
rcd. Additional meter tails are needed and the circuit will have to be tested
and certified before the supply company will make the connection to their
system.
Electrical supply - cable specifications
The cable size needed can be determined from the Table of Sizes.
You will require a 45A double pole isolating switch in the cable run. If you
prefer to locate this in the bathroom it must be a pull cord operated type.
Installing electrical cables to your shower
Plan the route carefully before starting. Cable is sold either by the metre
or on 50metre drums. Calculate the total amount of cable needed and then work
out the most economical way of buying the cable.
Terminating the electrical cables
Never cut the cable off too short, as mistakes will prove costly.
Always leave a small loop when terminating a cable. This will make it easier
to push the cable end into the terminal.
Connecting to the Consumer Unit
Always switch off the main isolator and take great care to be aware
of the dangers, before taking off the front cover of the consumer unit.
Safety!
Supplementary earth bonding It is essential to install supplementary
earth bonding when electrical shower units are installed.
