Extend 16A Radial with 1mm T&E?
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You have lied on this thread. It would be very simple to prove you haven’t lied but you refuse to do that, so therefore it must be a lie.
Do you want me to post more examples of you lying on this forum?
Do you want me to post more examples of you lying on this forum?
What sort of logic is that?
Which bit are you having a hard time understanding?
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Which bit are you having a hard time understanding?
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Not to mention you and BanAllSheds...
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So I've disconnected the existing FCU off and I'm fairly sure the cable is only 1.0mm and not 1.5mm - it looks somewhere between the two and, having measured it with a caliper it measures between the two, but I'd rather take the pessimistic view that it's 1.0mm.
It's not practical for me to replace the existing cable without removing a tiled floor which is out of the question at the moment, so the question really is what I can do with what I have.
There are clearly disagreements over what the regulations say about using 1.0mm cable however if we focus purely on the safety aspect; does 1.0mm cable being rated at 16A mean it'd be fine protected by a 16A MCB or do I need to consider the fact a 16A MCB won't actually break at 16A and fuse down with another FCU? If so, is 13A sufficient or do I need to go lower?
It's not practical for me to replace the existing cable without removing a tiled floor which is out of the question at the moment, so the question really is what I can do with what I have.
There are clearly disagreements over what the regulations say about using 1.0mm cable however if we focus purely on the safety aspect; does 1.0mm cable being rated at 16A mean it'd be fine protected by a 16A MCB or do I need to consider the fact a 16A MCB won't actually break at 16A and fuse down with another FCU? If so, is 13A sufficient or do I need to go lower?
The measurements of wires are 1 square mm. and 1.5 square mms.; not the diameters.
https://www.diynot.com/wiki/Electrics:flatpvccables
https://www.diynot.com/wiki/Electrics:flatpvccables
A 16A MCB is fine for a cable rated at 16A. You do not have to allow for anything else as far as the MCB is concerned.
The rating of the cable is reduced if installed in materials or conduit which might reduce the cooling of the cable.
The rating of the cable is reduced if installed in materials or conduit which might reduce the cooling of the cable.
Thanks. I stripped a short length of 1.0mm² and 1.5mm² to check my caliper and they measured at 1.14mm and 1.36mm respectively - not quite perfect but certainly within the realms of an uncalibrated "domestic" caliper!
All three cables in the existing FCU measured between 1.20 and 1.24 when I checked them so not quite either size but certainly closer to 1.0mm?
Can you confirm that there does not need to be any derating factors applied to your cable?
Ca, Cg, Cc, Ci
What is the highest ambient temperature of the cable route (normally 30°C)?
Is the cable run grouped with any other cable(s)?
What type of fuse or circuit breaker will be protecting the cable?
How is the cable run? Is it in any trunking, conduit etc, clipped to the surface, buried in the wall?
Most importantly, does the cable run at any point through any thermal insulation? If yes how much in mm?
Ca, Cg, Cc, Ci
What is the highest ambient temperature of the cable route (normally 30°C)?
Is the cable run grouped with any other cable(s)?
What type of fuse or circuit breaker will be protecting the cable?
How is the cable run? Is it in any trunking, conduit etc, clipped to the surface, buried in the wall?
Most importantly, does the cable run at any point through any thermal insulation? If yes how much in mm?
I don't think any derating factors will apply but just to confirm
- the cable route won't be subject to anything other than ambient British temperatures
- the cable isn't grouped with any other cables
- the cable is clipped direct on the wall at either end and runs under an uninsulated suspended floor for about 1.5 metres between
The cable does pass through the cavity wall between the garage and the house. The cavity is around 70mm so the cable will be surrounded by insulation for that distance - I'm not sure if any derating needs to be applying for that distance?
The circuit is currently protected by a standard B16 MCB and 30mA RCD
- the cable route won't be subject to anything other than ambient British temperatures
- the cable isn't grouped with any other cables
- the cable is clipped direct on the wall at either end and runs under an uninsulated suspended floor for about 1.5 metres between
The cable does pass through the cavity wall between the garage and the house. The cavity is around 70mm so the cable will be surrounded by insulation for that distance - I'm not sure if any derating needs to be applying for that distance?
The circuit is currently protected by a standard B16 MCB and 30mA RCD
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