Bends in conduit

[PC Electrics]

Ah! So is the total circuit length somewhat more than the 18m then?

I was about to suggest that surely you could use 6mm as with an 8.5kW shower 6mm should be good for up to about 40 metres or so.

 

[safedepth]

Ah! So is the total circuit length somewhat more than the 18m then?I was about to suggest that surely you could use 6mm.

Yes,

It's 18m external then further 6m inside from point of entry to point of use via switch position. By my calc's that's .4599 outside and (using 10mm) .924 inside.

= 5.5% What's the general opinion, is it shoddy work to use 6mm?

---------- AUTO MERGE Post added at 18:32 ---------- Previous post was at 18:20 ----------

Ah! So is the total circuit length somewhat more than the 18m then?I was about to suggest that surely you could use 6mm as with an 8.5kW shower 6mm should be good for up to about 40 metres or so.

Just reread your post.

I'm using the BRB and get this.

Vd = 7.3 (from table 4D4B) x 35a x meters/1000

Transposed, max length is 19.6m.

Vd = 7.3 x 35 x 19.6/1000

Vd = 5 volts.

Am I doing something different to you or just plain wrong?

 

[PC Electrics]

Yes,It's 18m external then further 6m inside from point of entry to point of use via switch position. By my calc's that's .4599 outside and (using 10mm) .924 inside.

= 5.5% What's the general opinion, is it shoddy work to use 6mm?

So far you've given us 18+6 = 24m

If we add 4m for distance to the Cu and a bit of slack:

A 8.5kW shower pulls 35.5A

6mm drops 7.3mV/A/m

vd = 28 x 35.5 x 7.3 / 1000 = 7.26V = 3.15%

well in

 

[safedepth]

So far you've given us 18+6 = 24mIf we add 4m for distance to the Cu and a bit of slack:

A 8.5kW shower pulls 35.5A

6mm drops 7.3mV/A/m

vd = 28 x 35.5 x 7.3 / 1000 = 7.26V = 3.15%

well in

Sorry,

I sit here thoroughly corrected. I've been thinking 5v not 5%! Bloody fool.

Cheers for that, you've just saved me from myself.

:Salute :Salute:Salute

GuinnessGuinness

 

[PC Electrics]

Sorry,I sit here thoroughly corrected. I've been thinking 5v not 5%! Bloody fool.

Cheers for that, you've just saved me from myself.

:Salute :Salute:Salute

GuinnessGuinness

He who makes no mistakes is doing nothing

You can't learn from mistakes you don't make

you're welcome

 

[batty]

Jobs getting cheaper 3 core 6mm is only

 

[Riggy]

the fact that the cable has already deteriorated and has burnt out once

I understand your viewpoint, and I'm not for disturbing your good night's sleep, but I read your original post as saying the fault occurred in the isolating switch (not exactly rare on electric showers), I would hazard a guess that the only damage to the existing cable is the burn back from the failed switch.

Your job, your conscience, your choice!

 

[safedepth]

I understand your viewpoint, and I'm not for disturbing your good night's sleep, but I read your original post as saying the fault occurred in the isolating switch (not exactly rare on electric showers), I would hazard a guess that the only damage to the existing cable is the burn back from the failed switch.Your job, your conscience, your choice!

You're right on all counts. We've all seen shower switches with burn marks and a lot worse, this was a hell of a lot worse, but like I said, I need a good nights sleep. Won't get that by reconnecting this cable. Far too much doubt in the install method.

As an aside, which I didn't mention in the original post, the shower is showing signs of age. I've informed the customer but they are reluctant to change it right now. Other benefit of new cable is future proofing the install.

Like I say, it could have been a bright shiny new unit resembling the dogs danglies, I still couldn't reconnect old cable.

I do however respect your opinion, we are all allowed one!

 

[Badger]

You're right on all counts. We've all seen shower switches with burn marks and a lot worse, this was a hell of a lot worse, but like I said, I need a good nights sleep. Won't get that by reconnecting this cable. Far too much doubt in the install method. As an aside, which I didn't mention in the original post, the shower is showing signs of age. I've informed the customer but they are reluctant to change it right now. Other benefit of new cable is future proofing the install.

Like I say, it could have been a bright shiny new unit resembling the dogs danglies, I still couldn't reconnect old cable.

I do however respect your opinion, we are all allowed one!

id have to back you up on this one, because id have had the same thoughts if i saw a damaged cable that appeared that damaged.