Hager MCCBs Advice needed

[thestig246]

Hi im currently been carrying out at periodic on a caravan park. the board is a hager with these massive mccbs. There are 16mm cables which feed onto caravan outlets and the mccbs are all rated at 125A's... I dont see why this has been done and dont think its acceptable, surely the biggest protective devices for a 16mm is 63a tops??

I wondered if anyone else has had dealings with these boards and can you still get the breakers for these boards so i can down rate it abit!

il try and get a picture up once i famble it out!

many thanks!

 

[atm84]

Firstly what ref of Hager Board and MCCB is it? What the installation method for the cables, how far is it? Are you sure that the MCCB aren't adjustable and have actually been down rated.

 

[Pete999]

Firstly what ref of Hager Board and MCCB is it? What the installation method for the cables, how far is it? Are you sure that the MCCB aren't adjustable and have actually been down rated.

I was going to say just that.

 

[spark 68]

It might be needed as backup protection for high prospective fault currents amongst other things.

 

[thestig246]

sorry for the vague details! its a 16mm 2core SWA Burried Supplying three caravans with 16a sockets. where theres a 30ma 16amp RCBO. unfortunately these ones are no adjustable. If i could get a picture up it would tell 1000 words haha.

 

[spark 68]

sorry for the vague details! its a 16mm 2core SWA Burried Supplying three caravans with 16a sockets. where theres a 30ma 16amp RCBO. unfortunately these ones are no adjustable. If i could get a picture up it would tell 1000 words haha.

I didn't expect the final RCBOs to be adjustable, I would have been surprised if they were

 

[thestig246]

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[thestig246]

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hope this helps basically you have a 16mm 2 core armored wired into a 125a breakers! surely thats too much for a 16mm? i just wondered if it had been done for a particar reason or was it all that was available..

 

[spark 68]

A quick Google it seems they are rated 15kA Ipf, which may be needed depending what the Ipf is at the intake of that board, how long is the run to the RCBOs/caravan pitch ?

 

[yellowvanman]

Can't see where the first picture fits into the DB picture!

 

[LeeH]

What's with the incomer colours? Black, Grey, Black with Grey tape.

 

[spark 68]

I suppose it is possible that overload protection has been omitted, and they are only providing fault protection for the 16mm SWA cable buried underground ?

 

[thestig246]

the 1st pic is on another db which is fed off this board as for tails theres alsorts of tricks like that going on, ive had a nightmare today, finding 0.50Mohm on my IR's as in places they have put undground joints in and just kept tapping off a cable, so you only have one cable comming to the caravan point and no way of splitting it ect. It seems a strange one as they have a 100a t/P on a 120mm cable and a 125a breaker on a 16mm cable!

the run would be aprox 50metres to the furthest pitch

 

[spark 68]

Sounds a bit of a pigs ear tbh, how many pitches/points does that MCCB feed ?

 

[thestig246]

it is mate, its on mum and dads holiday park, and ive had to tell them today that most of it needs rewiring as im getting really poor IRs bellow (1meg) there must be about 30 underground joints and they are inevitably failing!

Interestingly the previous person who carried out but on there report (no underground surveying on cables carried out, & 10% of insulation resistance carried out)

It varies really on that particualar board they are only feeding 3 caravans per 125a breaker.
whereas on the older part on the site theres about 10-15 running off some of the old 2c aluminium cables, (all with joints) :/