Main Supply fuse

[ban-all-sheds]

Seemed the results I got from TLC's calculator were just on the cusp so I decided to go with 16mm though I would rather have gone for 10mm and not had the anaconda wrestling match I will have with the 16mm.

I take it you checked that the 10.5kW rating of the shower is at 230V, not 240V, and that you haven't in fact got an appliance which will only draw 42A at 230V?

 

[securespark]

It seems Amy has her head screwed on the right way.

She looked it up on TLC's website and found it was borderline for her circumstances, in particular with reference to the effect of the loft insulation on the cable's ability to dissipate the heat it will produce.

 

[kevindgas]

16mm cable! - seems unusual is it a long run?

So if voltage drop isn't an issue, is 10mm² always enough for a 10.5kW shower?

no thats why i questioned it to be sure the OP wasn't paying through the nose for 16 if 10 was sufficient.

 

[Amy_B]

I'd much rather have used 10mm but I wasn't going to take the risk.
10k5 at 240, 9k6 at 230 and 43.75A as I recall

 

[Amy_B]

Night Night

 

[Amy_B]

PME Notice

• Amy_B
• 8 Mar 2009
• 1

Stick to board by incoming head

Protective Multiple earth notice - so TN-C-S?

Meter tails

• Amy_B
• 8 Mar 2009
• 1

Service Head

Cut out Detail

• Amy_B
• 8 Mar 2009
• 2

Cut out Detail

Main Cutout detail

CU

• Amy_B
• 8 Mar 2009
• 1

From Right To Left<br>unused empty, unused, Downstairs Lights , Upstairs lights, Sockets,Cooker

CU
Unused way, Fused unused. Downstairs Lighting, Upstairs Lighting, Sockets, Cooker

Earth Bonding to incoming gas

• Amy_B
• 8 Mar 2009
• 1

Earth Bonding to incoming gas pipe detail

Incoming Gas bonding

Spoken to EDF who think the main Cutout is 60A because that's what it usually is!

Can arrange to have upgrade to 100A or possibly 80A. All a bit vague. But network services line constantly busy, Hope eventually to speak to a real company electrician who has actual details of installation and services offered.

Still working on the spreadsheet for likely loads in addition to new shower.

 

[plugwash]

I wouldn't worry too much about the service fuse rating, a 60A BS1361 will take a LONG time to blow at 100A

 

[ban-all-sheds]

It seems Amy has her head screwed on the right way.

She looked it up on TLC's website and found it was borderline for her circumstances, in particular with reference to the effect of the loft insulation on the cable's ability to dissipate the heat it will produce.

Indeed - I was just wondering, as it was borderline, if it was because she'd assumed a 46A load and not a 42A one...

 

[ColJack]

I think it's time for a CU upgrade too..

60A max load on that one..

RCD protection needed

is there a bond to the water that we can't see there?

 

[Amy_B]

Bond to incoming water goes through wall and ceiling void and down to incoming water in kitchen. picture coming soon.

Cu is going to be split load unit like this:

Untitled

• Amy_B
• 9 Mar 2009
• 1

 

[banditboy]

how do you get 16mm cables into showers and switches...?

 

[Steve]

how do you get 16mm cables into showers and switches...?

Use a contactor.

 

[Amy_B]

Through the provided ingress points.

 

[Amy_B]

TLC Says:
230v 9K6W 5m run under more than 100mm insulation above plasterboard (even at 25 degrees C)
Required Cable Size 16 mm
Voltage Drop 0.584 Volts.
Percentage Drop 0.25%
Current Load 41.7 Amps
Max Cable Load* 47.4 Amps

 

[bongos]

Cu is going to be split load unit like this:

Untitled

• Amy_B
• 9 Mar 2009
• 1

You're going to need some RCBOs on the unprotected side in this case. Have you decided how the circuits will be split?