New Shower Installation

[curiousone]

i'm new to this forum and ask that you all bare with me.
i intend to install a new shower, a triton ivory III 9.5kW electric shower. the cable run will be no more than 10 metres long running along a void area. the existing consumer unit is of the older type..ie...it uses the old wired fuses. there are six fuseways the highest rating being 30 amp. there is a spare. the shower is a 9.5 kW Triton Ivory III. i would be obliged if someone could advise me as to the wether i can use the spare fuseway on the CU using the correct fuse wire ie 40/45 amp?...what cable thickness to use? and will i need to fit an MCB or RCB?......and what amperage should the RCB / MCB be?... i know i need to fit an isolating switch between the CU and the shower unit. i would be grateful for any advice you can give me. thanking you in advance.

curious.

 

[Steve]

Not sure if you know about Part P. Part P is a part of the building regulations which governs electrical work in dwellings. If you want to do this work yourself you must inform your local building control department. They will charge a fee (£60-120), which will include inspection and testing of your work by their electricians, at first and second fix.

Your fuse box sounds like its long in the tooth. What colour is it? If its brown/black, CAREFULLY remove the front, can you tell if the back frame of it is wood or plastic? If its wood, get it replaced before anything.

I would not advise putting a shower on such a fusebox anyway. Many of those fuseboxes were not designed for such heavy loads and wont accept devices over 30 amps. They also have zero provision for RCD protection, which your socket circuits require.

You must also upgrade your supplementary bonding in the bathroom to include the shower circuit.

I advise you to get an electrician to replace the fusebox with a modern consumer unit and a full periodic inspection of the whole electrical installation.

 

[curiousone]

hello crafty and thanks for your reply. i'm gonna take the safe route and fit a new consumer unit. the cu in place now has six fuseways of which one is spare. would be grateful if you could advise me as to what cu to have installed that would be legal and in line with current building regs. i'm on a small budget but dont want to compromise safety over costs. please advise as to what CU, RCD, MCB's compatible with each other. thanking you in advance.

curious

 

[Steve]

Are you wanting to do the work yourself? We always advise against this on this forum, due to the scope of the work.

However, you ask about the brand and type of CU. CU is Consumer Unit. Good brands are MEM, Hager, Wylex, MK, Crabtree (not an exhaustive list!).

If your electrician mentions Volex or Proteus, kick him out!

The RCD arrangements depends on the main earth supply. If you have an earth spike outside in the ground, you must have a main time delayed RCD. These are rather expensive pieces of kit. If you have a TNS (from the main cable sheath) or a TNCS (from the suppliers neutral cable, this will emerge from the main fuse block) earth you can use a standard main switch. These are generalisations and tests should be carried out to ensure the integrity of the main earth.

You then need a standard RCD protecting the sockets and shower circuits. The same brand as the Consumer unit.

You need the main bonding checking, to ensure it is up to scratch. This involves an earth cable to the gas and water mains.

 

[curiousone]

hello again crafty. i bought an MCG split board consumer unit and the MCB'S to match. it also has the RCD. i noticed that the buzz bar that came with the cw is in one piece. would i be correct in assuming that the buzz bar has to be cut so that there is two buzz bars, one for the protected side and one for the non protected side?...or does it fit onto the RCD and MAIN SWITCH?...I am thinking that i have to cut the buzz bar. any help would be appreciated. thanking you in advance.

curious

 

[electronicsuk]

If the CU is split load then you will have to cut the busbar to suit, depending on the number of RCD protected ways required. The fact that you had to ask this clearly shows that you aren't competant to be carrying out this work. You say "i'm on a small budget but dont want to compromise safety over costs", if you don't want to make that comprimise then please bring in a qualified electrician. Seriously.