Electric shower

[davegilsenan]

Hello,
I want to have my shower replaced as I do my bathroom. At the moment there is an electric shower there and I want to replace it with a pumped/electric unit. When I started looking at it and reading the manul for the new shower, it appears I should have a RCD and an MCB- My exisitng circuit has neither. Also the existing cable is 6mm...is this enough? The shower manual is ambiguous-it has 6mm in a chart but in another place recommends 10mm. The builded who is doing my bathroom did not notice or comment on any of this.
Any suggestions recommended.
Thanks, Dave.

 

[Spark123]

Your cable size will depend on the rating of the shower, how far the cable is run, how it is run and type+size of fuse/MCB. If the manufacturer says an RCD is required then one must be installed. You say pumped/electric shower, is this fed from a header tank? Modifying a circuit (i.e. changing its protective device) and modifying the installation wiring in a bathroom are both notifiable to your LABC under part p of the building regs.

 

[Steve]

"at the moment there is an electric shower"

ok, this explains why you have 6mm² cable.

"i want to replace is with a pumped/electric unit"

if your new shower requires a 6-10mm² cable, it is the same type of shower as before, an electrically heated, mains-pressure fed shower, with no pump. This is an electric shower.

The only showers with pumps require a 3A FCU and 1.0mm² cable, and drag both hot and cold water out of their respetive storage tanks. These are known as power showers

What is the rating of the shower you have now? and what type of fusebox / consumer unit do you have? if the instructions say you require an RCD, you MUST have one.

 

[davegilsenan]

The shower both pumps and heats the water and will be fed from a cold header tank. Methinks an electrician is needed!

 

[Steve]

The shower both pumps and heats the water and will be fed from a cold header tank. Methinks an electrician is needed!

these are quite rare, but spark123 informed me earlier, that they do exist. your old shower must have been quite weak, being fed from a header tank and not pumped

 

[davegilsenan]

The old shower was fed from the mains- but mains pressure here is terrible thats why we're going to feed the new one from a tank.