Terminating 10mm

[gazdkw82]

Where'd you get that CCC from because my regs don't show B for twin and skin

On suite guide

 

[hightower]

On suite guide

Table 6F, no column there for B mate.

 

[gazdkw82]

my books at home and i'm at work so I cant check. Perhaps iv referred to the wrong table

 

[gazdkw82]

Looks like I referred to table F5 (pvc multicore cables)

So in table F6 (flat insulated and sheathed pvc) I have a combination of reference method 100* and also partly ran in trunking.

10mm Reference method 100* allows a total of 45 amp. The shower 41amp.

I'm still happy with the choice.

 

[hightower]

Looks like I referred to table F5 (pvc multicore cables)

So in table F6 (flat insulated and sheathed pvc) I have a combination of reference method 100* and also partly ran in trunking.

10mm Reference method 100* allows a total of 45 amp. The shower 41amp.

I'm still happy with the choice.

What protective device dude?

 

[gazdkw82]

40amp.

However the actual current drawn will depend upon the voltage of the supply. 230 = 41amp 240 = 39 amp. The actual voltage I measured was 243 (39 amp)

 

[hightower]

40amp.

However the actual current drawn will depend upon the voltage of the supply. 230 = 41amp 240 = 39 amp. The actual voltage I measured was 243 (39 amp)

Bending the rules dude

 

[gazdkw82]

Bending the rules dude

Is it?

It even stated in the instructions for the shower that the actual current will depend on the voltage of the supply.

Is this way of thinking considered bad practice then??

 

[hightower]

Hmmm, not sure on consensus but I was taught your cable calcs are done on nominal voltage which would be 230

 

[telectrix]

40amp.

However the actual current drawn will depend upon the voltage of the supply. 230 = 41amp 240 = 39 amp. The actual voltage I measured was 243 (39 amp)

ohm's law says the opposite. just you get more kW @ 240V than @ 230V.

 

[gazdkw82]

P = V*I
I = P/V

I = 9500w/230v = 41A
I = 9500w/243v = 39A

Am I going about this the wrong way?

 

[hightower]

P = V*I
I = P/V

I = 9500w/230v = 41A
I = 9500w/243v = 39A

Am I going about this the wrong way?

You're right mate, but power is provided for a given voltage, in the UK it will be 9500W at 230v. Therefore if you do put 240v up it, it will actually produce ~9800W of power.

 

[gazdkw82]

You're right mate, but power is provided for a given voltage, in the UK it will be 9500W at 230v. Therefore if you do put 240v up it, it will actually produce ~9800W of power.

Ah. Makes sense. Thanks Hightower

So upon checking with my dad on the shower he's confirmed it's actually a 8.5kw.

So 6mm could have been fine, however I'm still glad I changed it because from the switch to the shower the cable was actually some kind of white flat twin and earth with no markings on it. God knows where that's comes from.

So to summarise:

37A shower, at nominal voltage ;-)
10mm T&E (part in trunking and part in the loft under insulation below 100mm)
45A double pole switch.
40A breaker

 

[uksrevivor]

Probably IMO the best choice to install the 10mm even though the shower is only rated at 8.5KW it will allow for any future upgrades to a more powerful shower with the correct testing beforehand obviously. All new builds install 10mm as standard nowadays so for me it was the right thing to do as I have been taught an electric shower is probably the highest load on any domestic install.

 

[btvc-electrical]

Looks like quite an old faceplate, consider changing this if you cant get it squeezed on, I find most newer faceplates have a smaller depth in the back.