shower unit

[honda]

when wiring a shower unit fitted with an mcb and rcd does it matter which side of mcb/rcd live feed is connected to?

 

[Spark123]

Yes, the MCB needs to be in the phase conductor.
Sorry if this sounds rude but to ask such a simple question means you should not really be doing the work - please for your own safety call in a competent electrician.
This work should also be notified to your LABC under part P.

 

[oharaf]

He is absolutely right on this one. You're about to work on the worst combination, electricity and water, it needs to be done properly and certainly needs to be notified.

Where in Yorkshire are you, perhaps I may be of assistance

 

[honda]

think i made a bad job of asking my question. am proposing to fit an mcb/rcd to an existing shower circuit as a replacement for an existing fused switch. what i meant to ask is it ok for the current to flow through the mcb in any direction or does it HAVE to flow in one certain direction only?

 

[Taylortwocities]

I assume by "flow" you mean does the feed go in the top of the bottom of the RCD? If so it depends on the manufacturer - with some it doesnt matter, most do mark the RCD side L and N.

If you mean something else by the word 'flow' please explain - as its Alternating current it will go from live to neutral, well - it sort of jiggles around, really, but that's another discussion...

 

[ban-all-sheds]

Somebody once posted here (I think) about this - re MCBs anyway.

He worked, or had worked, for a manufacturer, and he explained why it matters very much which way round MCBs are connected, but I can't remember what the reason was...

 

[333rocky333]

For a MCB I would look for a pic of the mcb in a board, see where the bus bar is and use that as the live in.

Most bars now tend to fit on the lower terminal nowadays

What make is it

 

[honda]

thanks for replies. by flow,yes i do mean feed .It's a Niglon one way CU fitted with a mcb and a rcd (both correctly rared for my application)

 

[rssteve]

i think your all missing the point, if it has an mcb and rcd, then the mains feed goes to the rcd first, then out the rcd to the mcb, then out the mcb to the shower. I am sure when you say the rcd you have a one way consumer unit with the rcd main switch.

 

[Taylortwocities]

It should come with a leaflet with installation instructions.

Don't forget to do all of the tests before you use it. There's no point having an RCD safety device if you dont check that it operates properly..

 

[honda]

i think your all missing the point, if it has an mcb and rcd, then the mains feed goes to the rcd first, then out the rcd to the mcb, then out the mcb to the shower. I am sure when you say the rcd you have a one way consumer unit with the rcd main switch.

thanks rssteve,that seems like the the answer i'm looking for. just to clarify,the 2 mcb terminals are not marked and the 2 rcd live terminals are marked 1 and 2. Number 2 terminal is at the bottom and is connected to the bottom terminal of the mcb with a small (busbar?)

 

[honda]

It should come with a leaflet with installation instructions.

Don't forget to do all of the tests before you use it. There's no point having an RCD safety device if you dont check that it operates properly..

appreciate your advice TTC, can confirm that all will be tested.

 

[RF Lighting]

As you are installing an additional CU, have you installed a single point of isolation for the whole installation?

Is the main earth sufficiently sized?

Is the Protective Equipotential Bonding in place and apropriatly sized?

Does the bathroom require supplementary bonding, or the existing bonding extending to your new circuit?