Electrical Engineering - 6mm Core getting hot

Author

6mm Core getting hot

Patty

2007-01-18, 9:25 am

Hi,

The 6MM core running from may shower to fuse box is getting hot and
smelling pretty bad when I shower.

The cable has been installed since I moved in over 10 years ago.

I replaced the shower which was 8.5 KW so I assume that the 6MM was
fine and didn't need replacing.

I assume the cable has been installed over 15 years ago.

Could this be the age of the cable or simply the shower when turned up
causing this.

I have a 30amp fuse in the distribution box.

any help appreciated.

Regards
Patty

Adrian C

2007-01-18, 9:25 am

Patty wrote:
> Hi,
>
> The 6MM core running from may shower to fuse box is getting hot and
> smelling pretty bad when I shower.
>
> The cable has been installed since I moved in over 10 years ago.
>
> I replaced the shower which was 8.5 KW so I assume that the 6MM was
> fine and didn't need replacing.
>
> I assume the cable has been installed over 15 years ago.
>
> Could this be the age of the cable or simply the shower when turned up
> causing this.
>
> I have a 30amp fuse in the distribution box.
>
>
> any help appreciated.
>
> Regards
> Patty
>

Can't help, but it will help others to know you are in the UK !

--
Adrian C

Patty

2007-01-18, 9:25 am

Hi,

yes I'm in the UK,

Many thanks

patty

Andrew Gabriel

2007-01-18, 5:25 pm

In article <1169115659.207842.182460@11g2000cwr.googlegroups.com>,
"Patty" <simplycisco@hotmail.com> writes:
> Hi,
>
> The 6MM core running from may shower to fuse box is getting hot and
> smelling pretty bad when I shower.

First thing, stop using it immediately.
Probably you have a bad connection, or a bad isolating switch
contact, or both (one frequently leads to the other).
This could start a fire.

> The cable has been installed since I moved in over 10 years ago.

6mm cable is good for something between 35A and 47A, depending
how the cable is routed, and assuming it's not routed through
any areas above 30C ambient, and is not too long a run.

> I replaced the shower which was 8.5 KW so I assume that the 6MM was
> fine and didn't need replacing.
>
> I assume the cable has been installed over 15 years ago.

If the cable has been running at or above maximum capacity in
a warm location, then its life could be as little as 15-20 years.
The cable terminations are a common place where it may have been
running well above temperature, and wrecked the cable.

> Could this be the age of the cable or simply the shower when turned up
> causing this.
>
> I have a 30amp fuse in the distribution box.

In which case circuit is designed for a 7.2kW shower, and
someone's fitted a more powerful one at some point without
regard to the circuit design.

If it's a 30A rewirable fuse, then you now have to derate the cable
by 0.725 which makes its current carrying capacity 25A to 34A,
which makes it barely suitable for an 8.5kW even in the most
optimistic case of surface clipped cable in an area not exceeding
30C.

> any help appreciated.

You would have to describe in much more detail exactly how the
wire is routed along its entire length in order to tell you
what its safe current rating is. However, this is rather
academic now it's started buring out, as it will need to be
replaced, so you can fit a 10mm² cable instead. You must
replace any accessories which have been subject to excess
heating too, which might include the isolating switch, parts
of the fuse box, ans possibly the shower itself. You also need
to make sure earthing is up to current standards, the supply
is up to the load, and you fit an appropriate fuse for the
circuit.

--
Andrew Gabriel

Nipple Vice

2007-01-19, 3:25 am

"Patty" <simplycisco@hotmail.com> wrote in message
news:1169115659.207842.182460@11g2000cwr.googlegroups.com...
> Hi,
>
> The 6MM core running from may shower to fuse box is getting hot and
> smelling pretty bad when I shower.
>
> The cable has been installed since I moved in over 10 years ago.
>
> I replaced the shower which was 8.5 KW so I assume that the 6MM was
> fine and didn't need replacing.
>
> I assume the cable has been installed over 15 years ago.
>
> Could this be the age of the cable or simply the shower when turned up
> causing this.
>
> I have a 30amp fuse in the distribution box.
>
>
> any help appreciated.
>
> Regards
> Patty
>

I think you should have an electrician look at it.

TimPerry

2007-01-19, 9:25 am

Patty wrote:
> Hi,
>
> yes I'm in the UK,
>
> Many thanks
>
> patty

sometimes old connections become oxidized. this makes a high resistance at
the connection which become hot when current passes through it. if you can
do it safely, tighten the wires screw terminal at the fuse panel.

if you are not familiar with electrical safety procedures you should call
someone who is to do this.

phil-news-nospam@ipal.net

2007-01-19, 1:25 pm

On Fri, 19 Jan 2007 08:55:15 -0000 Nipple Vice <slip@per.com> wrote:
|
| "Patty" <simplycisco@hotmail.com> wrote in message
| news:1169115659.207842.182460@11g2000cwr.googlegroups.com...
|> Hi,
|>
|> The 6MM core running from may shower to fuse box is getting hot and
|> smelling pretty bad when I shower.
|>
|> The cable has been installed since I moved in over 10 years ago.
|>
|> I replaced the shower which was 8.5 KW so I assume that the 6MM was
|> fine and didn't need replacing.
|>
|> I assume the cable has been installed over 15 years ago.
|>
|> Could this be the age of the cable or simply the shower when turned up
|> causing this.
|>
|> I have a 30amp fuse in the distribution box.
|>
|>
|> any help appreciated.
|>
|> Regards
|> Patty
|>
|
| I think you should have an electrician look at it.

I think the electrician should do more than just look at it.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2007-01-19-1053@ipal.net |
|------------------------------------/-------------------------------------|

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