Shower downgrade

[Ducksy]

Quick question guys shower needs downgrading was 10.5kw

Cable is 6mm on 40amp 60898 30mA RCD.

The 10.5kw element has failed so have advised customer a 8.5kw is more suitable for the cable/fuse size.

Do I need to issue a EICR for this as I'm changing the load.

I remember someone on here saying they only do MWC for replacing shower units on a related thread before (which I can't find), but you can't issue a MWC for a room containing a bath or shower.

What do you guys do.

Thanks.

 

[telectrix]

but you can't issue a MWC for a room containing a bath or shower.

first i've heard of that. i would just complete a MWC. how is the 6mm run, ref. method? if anything other tan method C , i would downrate the MCB to 32A.

 

[Ducksy]

Thanks tele what I meant was, due to it being a room containing a bath or shower, Doesn't it need notifying?.

It is clipped direct so cable is sufficient...just.

 

[telectrix]

as you are doing a like for like replacement, notification is not required.

 

[Ducksy]

You see that's where the issue is, it's not like for like as I'm changing the load characteristic although be it lower.....what happens if I was changing it for a higher KW.

Your right of corse, just me over thinking it.

Thanks tele.

 

[Guest55]

i would downrate the MCB to 32A.

you would ?
what happened to In >/= Ib ?
shame a 8.5kw shower pulls 37A lol.

as for cert , MWC will do as reducing the load doesnt require you to re-evaluate the circuit characteristics.
;-)

 

[Ducksy]

i would downrate the MCB to 32A.

you would ?
what happened to In >/= Ib ?
shame a 8.5kw shower pulls 37A lol.
;-)

I guess why people say down rate fuse is that it more Likely to trip rather then cable to melt.

Surly changing a protective device would need a EIC for the circuit .

 

[vini]

Surprised there is not more problems with a 6mm cable and a 10.5kw shower. I usually use a 10mm cable for that size of shower.

 

[somersetsparks]

I would point the OP to this thread with regards to Fuse size. http://www.electriciansforums.net/e...overload-protection-fixed-loads-new-post.html

 

[MDJ]

Surprised there is not more problems with a 6mm cable and a 10.5kw shower. I usually use a 10mm cable for that size of shower.

What if it is 2 mtrs from the DB? still 10mms or 8mm2 as someone mentioned the other day here LMFAO hahaha

 

[Darkwood]

Work out the current carrying capacity of the cable after cable calcs applied and this is the rating of the shower you can fit .... if you protection device is a little higher than the cable ccc this is not a worry as the device wouldn't need to give overload protection as it is a fixed load and by the nature of it been a shower circuit it is unlikely to be added to, i.e if your cable after calcs was rated to 43amps and you fit a 9.5kw shower which draws 41.3 amps at 230v then fitting a 45amp or 50amp is acceptable although i stress you shouldn't be designing and installing circuits using this regulation if that was the case then a largewr cable would be necessary. I would only use this regulation if you are in your situe with a similar set up to the above calc.


Ps if the cab;e runs through a loft that hasn't een insulated yet then apply calcs as though it is insulated which you should do anyway or ensure cable can't ever be covered.

 

[GLENNSPARK]

you would ?
what happened to In >/= Ib ?
shame a 8.5kw shower pulls 37A lol.

as for cert , MWC will do as reducing the load doesnt require you to re-evaluate the circuit characteristics.
;-)

well it does Biff....but you know that an MCB to BSEN60898 will hold for 1.45 its operating current for upto an hour before letting go...it should be OK...unless theres 2 in that shower...undisturbed....lol..

 

[vini]

What if it is 2 mtrs from the DB? still 10mms or 8mm2 as someone mentioned the other day here LMFAO hahaha

2 metres from the DB? Now that would be nice, if it ever happened. Yes I would use 10mm every time. A short run is not going to create a huge extra expense.