Help: very low voltage in shower!

[bluesky]

Hi all,

My electrical shower suddenly stopped working. I thought it was broken and then bought a new one. But the new shower still does not work. So I tested the cable, found only 55 volts in the electrical shower between live and neutral. But on DB, it is 240 between live and neutral.

It is really strange that it is just a short cable buried in the wall,how come voltage drop is so big? also in the last 2 years the shower worked quite well, anyone has any ideas?

thanks a lot for any help.

 

[bugsy]

I suggest you check connections at the shower isolator/ pull switch ( loose connection) first.

 

[m4tty]

^^^ ill second that ^^^

 

[bluesky]

just checked the isolator, dam, the cable has melted there, i have to replace the isolator,

the shower is 8.5kw, cable is 6mm2, this should be fine, also i have used it for 2 years, but it only melted recently?

 

[m4tty]

May have been a loose connection casuing high resistance

 

[bluesky]

thanks a lot

 

[bugsy]

just checked the isolator, dam, the cable has melted there, i have to replace the isolator,

the shower is 8.5kw, cable is 6mm2, this should be fine, also i have used it for 2 years, but it only melted recently?

Are sure about the 6mm and i'd be inclined to replace the isolator

 

[bluesky]

yes, it is 6mm, also have changed the isolator, the old one has been slightly burnt...

 

[bugsy]

yes, it is 6mm, also have changed the isolator, the old one has been slightly burnt...

I thought it might be!

6mm might be pushing it though

 

[bluesky]

I thought it might be!

6mm might be pushing it though

do you mean 6mm is not enough?

 

[empress]

do you mean 6mm is not enough?

if its a decent length of run and has insulation round it your on the limit with a 8.5kw shower
not ideal.
had plumber a ring me up today asking about a shower swap a customer had bought .
"can i put this 10.5kw instead of the broken 8.5kw which is on 15m run of 6.0mm2"
answers on a post card

 

[bugsy]

do you mean 6mm is not enough?

Well all Im saying is check the load / run/ multiplying factors and do a calc

 

[lloyd1980]

it has to be a loose connection
if shower cable check the board and then check the switch
failing that check shower
if none of that
you need a complete rewire
and a new substation
what a bummer
I can give you a price on all

 

[uksel]

what size breaker you got on that 6mm cable there?

correct me if i'm wrong - rough current demand of the shower

8500/230 = 36.95

CCC of cable is dependant on installation method but you'd probably be looking at most ~34A

 

[bluesky]

what size breaker you got on that 6mm cable there?

correct me if i'm wrong - rough current demand of the shower

8500/230 = 36.95

CCC of cable is dependant on installation method but you'd probably be looking at most ~34A

it is 40A, looks all right