10 mm supply to flats

[egginyourface]

Ive been asked to do a periodic inspection on a couple of properties and when i opened consumer unit covers i found they had both been supplied with what looks like 10mm armoured. I compared cable size to 10mm t ande for the shower and it looked the same size.

I opened the isolator swtich next to the meter and found 100 amp fuse...

ones a bed sit and the other is 2 bed flat.

In the 2 bed flat, they have a hob on 32 amp breaker, mega flo water heater, 25 spots, w machine. 3 x aircon units..

In the bed sit i found 9.5kw shower, ariston water heater, w machine, 14 spots and a stand hob which works off a 13 amp plug top.

 

[malcolmsanford]

Ok so

1 Is the isolator feeding both installations ?
2. How long are the 10mm sub mains?
3. Is there any sign of heat damage?
4. Did you code it?
5. What is the main intake fuse?
6. Did you take any load readings? (though as it is winter the AC units would have been off)

 

[supasparxs]

hmmm

100a fuse protecting a 10mm cable.....

so a 10mm radial can take about 50ish amps (ball park figure, no regs to hand just a guess)
and fuse which can overload by 40% so it may draw upto 140 amps,

Personally I think the cable is a "little" under rated!!!

A code 1 fault and I wonder how it was passed by anyone in the past

 

[egginyourface]

theres a seperate isolator to each flat
the 2 bed flat run look s under 10 meters and the bed sit is probably about 7meters. Cabling is in partition walls.
No sign of heat damage. Install is quite new.
I only did a visual inspection need to go back and test properly along with load readings
The intake is 100 amp
The aircon units are used for heating aswell

 

[malcolmsanford]

theres a seperate isolator to each flat So 1 x 100amp fuse in each isolator. A 70c SWA Erection method C will give you 67 amps so you could downgrade the fuse to 60amp that sorted

the 2 bed flat run look s under 10 meters and the bed sit is probably about 7meters. You will have to downgrade the fuse because both tails are over 3mts and there reg 434.2.1 is contravened

Cabling is in partition walls. Method C
No sign of heat damage. Install is quite new.OK

I only did a visual inspection need to go back and test properly along with load readings
The intake is 100 amp
The aircon units are used for heating aswell

I would recommend you advise down grading the fuse to a 60 in each isolator and code it a 2

 

[J&M Electrical]

If its an armoured the sheathing is usually thinner than on normal T&E so it could well be a 16mm Armoured. (or did u check by comparing the actual copper?)

 

[egginyourface]

thanks for pointing that out. I only compared it by looking at the sheathing round the conductor. Didnt check the copper

 

[J&M Electrical]

thanks for pointing that out. I only compared it by looking at the sheathing round the conductor. Didnt check the copper

No probs, i only know because i almost shat my pants after pulling in 50 odd metres of the stuff through a house before checking and then came to make it off and thought **** a rubber duck its only 10mm, but then i realised the sheathing was thinner.