Discuss cable size for shower in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

Reaction score
1
Hi guys I have been asked to fit new shower and run new cable for it too, looking at regs book it would have to be reference method 103, which for 8.5kw shower would mean 16mm cable, can terminals in the shower take 16mm and the terminals in the isolator? I have tried looking for different cable routes but the board is downstairs and the bathroom is upstairs. 10mm is what is in at the moment. I don't usually do domestic electrical work so any advice would be great. I just thought 16mm was a bit overly for 8.5kw shower.
 
Hi guys I have been asked to fit new shower and run new cable for it too, looking at regs book it would have to be reference method 103, which for 8.5kw shower would mean 16mm cable, can terminals in the shower take 16mm and the terminals in the isolator?
Are you pulling sub main for it has well
what volt drop for this.
 
What calculations have you done to arrive at 16mm2 for an 8.5 shower?
.
 
irrc, 10mm ref.103 is down to 32A. shower is 35A (and a bit).
 
I just used one of those online volt drop calculator things and they come up with 16mm also. just I was looking at the regulations book for 10mm ccc and noticed with method 103 that it would be rated to 32 amps therefore I would have to go to 16 as the shower is 35.4 amps. I was just going to run 10mm but I guess I should go 16 to be in line with regs. I cant see any other different cable route. I have spoken to other electricians and they have said to just run 10mm but I would rather be safe than sorry. I usually work offshore so this domestic side is something im not really familiar with. thanks for your help
 
just used one of those online volt drop calculator things and they come up with 16mm also. just I was looking at the regulations book for 10mm ccc and noticed with method 103 that it would be rated to 32 amps therefore I would have to go to 16 as the shower is 35.4 amps. I was just going to run 10mm but I guess I should go 16 to be in line with regs. I cant see any other different cable route. I have spoken to other electricians and they have said to just run 10mm but I would rather be safe than sorry. I usually work offshore so this domestic side is something im not really familiar with. thanks for your help
Rule with a big thumb stick in 10mm
For a up grade of shower.
 
Hi guys I have been asked to fit new shower and run new cable for it too, looking at regs book it would have to be reference method 103, which for 8.5kw shower would mean 16mm cable, can terminals in the shower take 16mm and the terminals in the isolator? I have tried looking for different cable routes but the board is downstairs and the bathroom is upstairs. 10mm is what is in at the moment. I don't usually do domestic electrical work so any advice would be great. I just thought 16mm was a bit overly for 8.5kw shower.
You don't mention in your post the length of the run of this circuit.
 
Hi guys I have been asked to fit new shower and run new cable for it too, looking at regs book it would have to be reference method 103, which for 8.5kw shower would mean 16mm cable, can terminals in the shower take 16mm and the terminals in the isolator? I have tried looking for different cable routes but the board is downstairs and the bathroom is upstairs. 10mm is what is in at the moment. I don't usually do domestic electrical work so any advice would be great. I just thought 16mm was a bit overly for 8.5kw shower.
Well there is a little bit of history in the making here for me. An 8.5 kW shower wired in 16mm?.Am really curious to know the installation conditions for this one. I must assume it is immersed in insulation and on the top floor of a 3 story structure?
 
16mm for the run through insulation then 10mm from an isolator switch of you need to drop cable size.
 
Think how many small showers have been originally wired in 6mm, then attics filled with scratchy wool, then the shower upsized to a 9.5kW.

the vd must be massive.
 
And theystill probably running fine
Yes. I posed a question on a different forum as to whether any spark had come across a heat damaged 6mm cable supplying an electric shower.?. No one had. I personally never have. House I, m currently renting has our shower wired in 4mm (lying on top of, not under insulation) .To date every shower repair I have personally carried out has always been either a heat damaged pull switch or a heat damaged rcbo
 
Yes. I posed a question on a different forum as to whether any spark had come across a heat damaged 6mm cable supplying an electric shower.?. No one had. I personally never have. House I, m currently renting has our shower wired in 4mm (lying on top of, not under insulation) .To date every shower repair I have personally carried out has always been either a heat damaged pull switch or a heat damaged rcbo
It’s bad practice though isn’t it, when carrying out EICR’S I code it as a C3 with no thermal effects and downgrade mcb to 32A rather than the 40A installed. If I’m asked to replace faulty shower which is 8.5kw or above on a 6mm cable I will renew cable with 10mm it’s the right thing to do isn’t it.
 

Reply to cable size for shower in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

YOUR Unread Posts

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock