Total DIY Rewire - Part 2

[PreferNotToDieOrBurn]

Cables are designed to run at upto 70 degrees. This is normal.

I'm going to request this thread is locked to save a lot of people existing their time for you.

I'm sorry but a cable running at 70 degrees is not normal. It may be rated to run up to 70degrees but a cable that is warm to the touch is a clear sign of something being wrong. At 27amps on a 2.5mm cable the heat produced per foot of cable length is around 1.5watts equiv. At 16 amps (32amp ring final) it's less than half a watt. In order for the cable to heat up to a point where it is warm to the touch you would need around 45amps pumping through a 2.5mm cable. If the cable is wrapped in high performance insulation that figure might be more like 35 amps. Either way, stupid numbers.

Further leaching of PVC occurs due to heat, not due to the compounds in hot glue. Hot glue melts around 100-120 degrees and stays at that temperature for less than 30 seconds. Time is the second factor associated with leaching. If the cable is rated to 70 degrees then the leaching that may or may not occur would occur regardless of the presence of hot glue.

Your comments illustrate why I don't simply take every little bit of dumbarse advice. You are clearly less competent than I am.

This thread is serving as both a blog and a place for me to ask questions. If you don't want to participate that's your prerogative.

 

[PreferNotToDieOrBurn]

Perhaps in that case you have a suggestion?

Take the cables up in a duct.

Thanks - we don't have any ducts.

How do you suggest getting the cables (5 x 2.5mm, 2 x 1.5mm) from the CU, into the loft?

You could take a single cable as a sub main from the meter location to a CU in or just below the loft. This might mean 2 consumer units but if it makes for safer installation a small price to pay.

We are doing a sub-main to the garage but in terms of running cables in corner safe zones I don't see how this would solve the problem. We could easily do this mind you and if it genuinely solved the problem then I wouldn't have an issue with installing a second CU in the main bedroom (the only logical location, directly above the main CU) but I don't see the advantage of running on 10mm cable as opposed to 7 smaller cables in the same location. Arguably smaller cables would be safer because they trip more easily.

 

[bernardgreen]

[Your comments illustrate why I don't simply take every little bit of dumbarse advice. You are clearly less competent than I am.

That's it for me. Go and get advice from those who agree with you.

Edit Your calculations for power dissipation ( heat generation ) in a cable carrying current are incorrect.