Moving electric shower, cable extension

[DrDan]

Hi all,

I need to move my existing electric shower about a foot to the right as I'm having a wider bath fitted and it's currently in the way of where the screen will sit. I'll need to connect about a foot of cable and the join will be behind tiled Aquapanel. The shower will only be used if the combi packs up.

I'm not sure what rating the cable is but the width of the flex is about 18mm, the shower is 10.8Kw and there's an RCD w/50A fuse in the CU.

Can I use a standard junction box to join everything up, should I bury the join and cable back in the wall and tile over as further protection, even though the Aquapanel is there?

Cheers...Dan

 

[ban-all-sheds]

I need to move my existing electric shower about a foot to the right

Unless the cable to it already runs horizontally you'll need to put a new one in, running down from the ceiling or up from the floor.

I'm not sure what rating the cable is but the width of the flex is about 18mm

//www.diynot.com/wiki/electrics:flatpvccables

Can I use a standard junction box to join everything up, should I bury the join and cable back in the wall and tile over as further protection, even though the Aquapanel is there?

No, no and no.

Junction boxes which use screwed connections must remain accessible.

There are rules for where concealed cables may run, so if your plan was to change the direction of the cable at that point, i.e. if the existing cable runs up or down to the shower, you may not do that because tiles and aquapanel will not provide adequate protection for such a cable route.

//www.diynot.com/wiki/electrics:walls


Lastly, after the cable has been extended, or replaced, it will need testing for continuity, polarity, insulation resistance and fault loop impedance.

 

[JohnW2]

I need to move my existing electric shower about a foot to the right as I'm having a wider bath fitted and it's currently in the way of where the screen will sit. I'll need to connect about a foot of cable and the join will be behind tiled Aquapanel. ... Can I use a standard junction box to join everything up, should I bury the join and cable back in the wall and tile over as further protection, even though the Aquapanel is there?

No. You are not allowed to have any join in a cable which is not accessible for inspection, testing and maintenance - and that clearly would not be the case if it were behind Aquapanel and tiles! The only exception is if one uses a 'maintenance free' junction box, but I doubt that you will find one which can take cables as large as those normally used for a shower. You may therefore have no choice but to replace the cable, at least as far back as somewhere (e.g. loft space) where a junction box would be 'accessible'. If you did use a JB, it would have to be a special high current (probably 60A) one - not a 'standard JB'.

The new (buried) cable needs to be in the 'safe zones' created by the shower - essentially vertically or horizontally aligned with the shower unit.

There will probably be debate as to whether this work would be 'notifiable'. Installing a new shower (when there had not been one previously) certainly would be. Replacing an existing shower (in the same place) probably wouldn't be. You are talking about a 'grey area'.

Kind Regards, John

 

[DrDan]

A minefield I see, I thought as much!

OK...the cable currently comes through from above the kitchen cupboards and vertically down behind the tiles to the shower.

- I guess I'll cut off the cable in the kitchen where it currently goes into the wall
- The existing cable on the shower side will stay in the wall as it's no longer used.
- I'll chase a channel and put another cable vertically up and through the wall from the new shower location 18 inches to the right.
- Join them up with a 60A JB.
- I'll then get someone to come in and test the continuity etc.

Sound any better?

 

[JohnW2]

- I guess I'll cut off the cable in the kitchen where it currently goes into the wall
- The existing cable on the shower side will stay in the wall as it's no longer used.
- I'll chase a channel and put another cable vertically up and through the wall from the new shower location 18 inches to the right.
- Join them up with a 60A JB.
- I'll then get someone to come in and test the continuity etc. ...
Sound any better?

Definitely better - provided that the 60A JB is somewhere 'accessible'.

Do I take it that the shower circuit already has RCD protection? If not, you would have to do something about that.

Kind Regards, John

 

[DrDan]

Yes, JB will be above the kitchen cupboards but not hidden.
Yes, RCD and 50A fuse in CU.

Thanks for the advice you've given, it's much appreciated!

 

[JohnW2]

Yes, JB will be above the kitchen cupboards but not hidden. Yes, RCD and 50A fuse in CU.

That sounds OK then.

Thanks for the advice you've given, it's much appreciated!

You're welcome.

Kind Regards, John

 

[ban-all-sheds]

Can you not replace the entire cable from the CU? Always best to avoid junction boxes if at all possible.

 

[EFLImpudence]

Do you not have a shower switch in the room?