10MM ELECTRIC CABLE FOR SHOWERS

Instantaneous Electric Showers are still one of the most popular types of shower sold in the UK today. Which is why Triton manufactures an extensive range to suit all tastes and budgets.
An electric shower simply connects to a cold water supply and your mains electric, so it's versatile enough to suit any home no matter what your plumbing system.
They are easy to install and they give you and your family instant hot water - any time, day or night.
So, what are the electrical requirements you need to know before you can choose an electric shower?
First of, all electric showers need to connect to your mains electric supply.
More to the point, it must have its own dedicated supply from your consumer unit.
It must not be connected to a ring main, spur, socket outlet, lighting circuit or cooker circuit.
The important thing is to ensure that the electric supply is adequate for the shower and existing circuits.
Check that your consumer unit has a main switch rating of 80A or above and that it has a spare fuse way to take the fuse or Miniature Circuit Breaker (MCB) for the shower.
The correct rating of MCB or fuse will depend on the kilowatt rating of the shower that is to be fitted. For more information on kW ratings take a look at our "What is a kW rating?" video.
If your consumer unit has a rating below 80A, or if there is no spare fuse way, then the installation will not be straightforward.

It may require a new consumer unit serving the house or just the shower.
For your protection, a 30mA residual current device must be installed. This may be part of the consumer unit or a separate unit.
The size of electric cable you need from the consumer unit to the shower depends on a number of things, such as - the kilowatt rating of the shower and the method of installing the cable.
i.e. is it, or will it, be surrounded by loft or wall insulation. As a result, the cable could be anything from 6mm, to 10mm, or even 16mm.
To obtain full advantage of the shower, use the shortest cable route possible from the consumer unit to the shower.
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.
Finally before your electrics can go into the shower unit, you need to install a 45 amp double-pole isolating switch into the circuit.
This can either be installed inside or outside of the bathroom, but it must be readily accessible to switch off after using the shower.
Once you've fitted the switch into the circuit, all you have to do is complete the cable to the shower.
Depending on the model of shower, the cable will enter through either the top, bottom, sides or back of the unit.
Simply connect into the terminal block making sure the connections are good and tight so there is no risk of the cable overheating.
The final thing to say is that all electric showers must be installed in accordance with all the relevant water supply, electrical and building regulations.
To find out what the plumbing requirements are for the installation of an electric shower, why not take a look at our complementary video "Electric Showers: Plumbing Requirements.

Electrical Cables, Electrical Flexes and Electrical Wires

Please note colours in these images are only representative and may not be the exact colours as found in your cables etc.
Please remember when attempting any electrical installations at home that you are obliged to get the completed job tested by a fully qualified electrician and obtain a minor works certificate. Failure to do this may render your house insurance invalid and you may have difficulty selling your home.
We get asked a lot which cable should be used to supply a lighting circuit or which flex to connect a washing machine to so we have produced a project with tables to allow you to see the difference between all of them. Scroll to the bottom for all tools and equipment.
Electric Wiring Domestic book available from Amazon
Wiring and Lighting book available from Amazon
It is vital to remember that values for cables and flexes can change in domestic situations. A cable in an insulated loft space will get hotter, much more quickly, than a cable looped through garage rafters. Please seek professional help if you are in any doubt whatever. As with most formulas in the building trade there are regulations defining specific boundaries for the use of all materials. Factors such as resistance and voltage drop may need to be assessed and taken into consideration when working out cable runs. Electricity is dangerous and each year an average of 10 people die and 756 are seriously injured in accidents involving unsafe fixed electrical installations and appliances in the home (Figures courtesy of BBC)
The term cable, amongst other things, means "an encased group of insulated wires" . A cable is a fairly inflexible (although of course they can be bent) set of wires used to supply the electricity to certain points in your home. Your meter box is supplied through a cable, sockets are supplied by cables and your lights are fed through cables. A cable can carry many wires depending on the job it needs to do. Most domestic cables carry a black wire which is usually for the neutral current, a red wire for a live current and a bare wire to take residual current to earth. This cable is called 2 core and earth. From 1st April this year all colour codes are to change. For details of these changes please see the link to the Institute of Electrical Engineers. In essence, for domestic use, the cable wire colours will change to those of the flex colours. For additional information see www.iee.org/oncomms/pn/betnet/index.cfm
2 core and earth 1.5mm cable
The bare wire, when the cable is used, should be marked by a green and yellow earth sleeve.
Another cable used a lot in domestic lighting is called 3 core and Earth. The extra core (wire) is in a yellow insulating sheath and is used as an extra conductor to carry power between 2 or more switches operating lights.
3 core earth cable image
Special lighting switch cable can be bought. This is called "Twin red core" and is used as switch cable for your lights. Often this is replaced, by electricians, who use an ordinary 2 core and earth cable as a switch cable and place a little red tape around the black wire in the cable. See our project on lights and switches.
A Flex (abbreviation of flexible) is a flexible cable used to carry electricity from a power point to an appliance. Most appliances are portable and in a lot of cases need to move quite a lot (irons, toasters etc) so the cable supplying them, should it twist or bend, needs to become straight again with the minimum of effort.
Appliance flex
Different cables and flexes are used for different jobs because they are thicker and can carry more current and have more, or less resistance. Resistance can be seen as electrical friction and the wires in the cable or flex will absorb some of the energy in the current, allowing a little less to reach the target than was sent.
High energy users such as electric showers and immersion heaters are supplied by thicker wires than are radios as the current that the appliance needs is considerably greater.
Cables supplying circuits etc should be used as in the following table.
Please note again that installation of cables depends on the position they are to be in, the temperature of the area or void, the length of the run, the grouping of the points they serve and the type of device (Fuse, RCD etc) by which they are protected. The first table below is for cables which are installed by method 4 "enclosed in an insulated wall" The second table is for cables installed by method 1, "clipped direct". As you can see there is quite a difference in rating so be absolutely sure you are doing the right thing. Also remember that while it is not an offence to make electrical installations yourself, it is an offence to use them without them having been checked by a qualified electrician. Even a simple socket addition now has to have a minor works certificate. Your house insurance may not be valid if you do not comply with the regulations.

Electric Cable Sizes and Amp Ratings UK | Electrical Resistance and Cable Rating Tables

Summary: Cable sizes for electrical use in the UK. Why do we have different sizes of cables and which size of electrical cable do you need at home? Our handy tables showing rating in Amps help you to check you are using the right cables for the right job.
Cables are used for different applications because they are differing thicknesses and can cope with differing currents safely with differing amounts of electrical resistance. A simple way to explain resistance is to see it as electrical friction.The cable will slow down some of the energy in the current. This means a little less current will reach the target than was actually sent.
Electric cookers, electric showers and Immersion heaters use a great deal of current and therefore require thicker cables. If a cable is too thin for the job it is being asked to do it will get too hot and catch fire. Generally it can be said that any cable carrying current to an appliance that is intended to produce heat will have a bigger current rating and bigger cable.
Also to be taken into consideration is the distance of the appliance from the electrical source. The greater the distance, the greater the resistance and the less current that will be available at the other end.
Cables must be placed in a situation where they will not be overheated. If cables are run in a loft they must not be placed under insulation and if they are run in insulated walls they will carry a different rating. Please check the tables below and if you are unsure please seek the advice of a professional. Please also note that a lot of electrical work is now covered by the building regulations and requires an installer with the appropriate qualification. Please see our project on Part P .
The type of device which is protecting the point the cable serves is also taken into consideration. These devices are fuses, mcbs, rcds etc and are covered in another of our electrical projects,
The tables below show two different cable and amp ratings. The first table is for cables installed by what is known as Method 4. This is cables enclosed in an insulated wall. The second table is for cables fixed using method 1. This is called clipped direct.
Table 1: Cables enclosed in an insulated wall: Method 1