ray-bentos
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- Joined
- Jan 22, 2014
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- 18
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Hi
Got my first Elecsa assessment next week after finally deciding to go it alone.
Not done any notifiable work so far, LABC costs make it prohibitively expensive so need to get registered.
Completing a consumer unit change for my mum, going to use it as my assessment piece, just hit a potential snag (I think I've convinced myself its OK, check my reckoning):
Just been to assess the job this evening ahead of tomorrows job, noticed what could be a problem.
The shower is an 9.5KW on 6mm T&E. The cable goes up from the CU to the ceiling clipped direct to wall, perhaps 2m within the void between down & upstairs (so would assume clipped direct in there, no thermal insulation to worry about) upon where it goes up through an airing cupboard (again, clipped direct) to the switch in loft (no insulation covering) and back down again to the shower (as far as I can tell all clipped direct). Its currently on a 32amp MCB but I plan to up this with new CU. If it was an install I had done myself I would have changed for 10mm however after some discussion with my customer (MUM!) upgrading the cable is out of the question (IE: it worked fine before....)
According to OSG 6mm clipped direct is good for 47amp, and as its only a short run (I estimate maximum 12m) volt drop is only 3.2V so well within value. I haven't used a clamp meter to confirm exactly what current is being drawn (my clamp meter is only cheap so not the most accurate) however if we work on worst case scenario (9500/230=41.3) can I use a 45amp MCB, should provide protection against short circuit (bearing in mind 6mm REF method C) within the capabilities of the cable, and note on some sort of design sheet my calculations to show I'm not just trying to wing it?
Got my first Elecsa assessment next week after finally deciding to go it alone.
Not done any notifiable work so far, LABC costs make it prohibitively expensive so need to get registered.
Completing a consumer unit change for my mum, going to use it as my assessment piece, just hit a potential snag (I think I've convinced myself its OK, check my reckoning):
Just been to assess the job this evening ahead of tomorrows job, noticed what could be a problem.
The shower is an 9.5KW on 6mm T&E. The cable goes up from the CU to the ceiling clipped direct to wall, perhaps 2m within the void between down & upstairs (so would assume clipped direct in there, no thermal insulation to worry about) upon where it goes up through an airing cupboard (again, clipped direct) to the switch in loft (no insulation covering) and back down again to the shower (as far as I can tell all clipped direct). Its currently on a 32amp MCB but I plan to up this with new CU. If it was an install I had done myself I would have changed for 10mm however after some discussion with my customer (MUM!) upgrading the cable is out of the question (IE: it worked fine before....)
According to OSG 6mm clipped direct is good for 47amp, and as its only a short run (I estimate maximum 12m) volt drop is only 3.2V so well within value. I haven't used a clamp meter to confirm exactly what current is being drawn (my clamp meter is only cheap so not the most accurate) however if we work on worst case scenario (9500/230=41.3) can I use a 45amp MCB, should provide protection against short circuit (bearing in mind 6mm REF method C) within the capabilities of the cable, and note on some sort of design sheet my calculations to show I'm not just trying to wing it?
