New Installation Problem

[jengo883]

Sorry guys, i was reading your replys and saying what, but you would have needed a cyrstal ball,

It was fitted with 16 amp and i replaced with 10 amp

Sorry

Today i was fitting new light fittings in a new flat.

The company who carried out the install are members of the NICEIC.

But when i was checking the circuits i found the following,
1, Circuit wired in 1.00mm but supplied from a 10 amp type B breaker.

2, The lights have been looped at each light switch all the CPC are twisted together and in the one bit of earth sleeving.

Would you just note your findings on the minor works certificate or would you advise the customer to take this up with the main contractor of the housing project.

Have any of you guys came across these problems?

 

[ban-all-sheds]

1, Circuit wired in 1.00mm but supplied from a 10 amp type B breaker.

And.....?

What do you think the capacity of 1mm² is?

2, The lights have been looped at each light switch all the CPC are twisted together and in the one bit of earth sleeving.

Tacky, but as long as that is not the only method of achieving continuity, i.e. as long as the cpcs are also in earth terminals, it's no more than that.

Would you just note your findings on the minor works certificate or would you advise the customer to take this up with the main contractor of the housing project.

What would you put on the MWC, and why?

What complaint would you suggest the customer makes, and why?

 

[industryspark]

im with BAS on this one, dont think the rating of 1mm t&e drops below 10A with any method of install so technically its all ok. bit unconventional maybe and not the norm but ok.

the cpc's in the same sleeving ive seen hundreds of times. normal practice.

think this is more a sloppy worksmanship issue by the sounds of it but certainly nothing wrong.

 

[ban-all-sheds]

im with BAS on this one, dont think the rating of 1mm t&e drops below 10A with any method of install so technically its all ok. bit unconventional maybe and not the norm but ok.

Might even reduce nuisance tripping when lamps fail.

 

[industryspark]

just popping down to the wholesalers see if they'l exchange my stock of 6A mcb's for 10A!

 

[securespark]

My teaching is that 1.0mm cable=6A, 1.5mm = 10A.

No-one else?

 

[JohnD]

If the B10 on the lighting circuit is to reduce nuisance tripping when a filament lamp fails, wouldn't a C6 do it better? It has the same tolerance of a quick load as the B10.

 

[ban-all-sheds]

My teaching is that 1.0mm cable=6A, 1.5mm = 10A.

No-one else?

'tis the ROT. But if you look at 4D5A....

If the B10 on the lighting circuit is to reduce nuisance tripping when a filament lamp fails, wouldn't a C6 do it better? It has the same tolerance of a quick load as the B10.

Does it have the same EFLI limit for a 5s disconnect? Can't be @rsed to look right now...

 

[Adam_151]

If the B10 on the lighting circuit is to reduce nuisance tripping when a filament lamp fails, wouldn't a C6 do it better? It has the same tolerance of a quick load as the B10.

Does it have the same EFLI limit for a 5s disconnect? Can't be @rsed to look right now...

Quick rule of thumb is king here:

C6: 6A x 10 = 60A to gareentee tripping (and the lower band: 6Ax5 = 30A)
B10: 10A x 5 = 50A to gareente tripping (and the lower band: 10Ax3 = 30A)

 

[ban-all-sheds]

So whatever you've got in the van, then...