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]

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 ?

That what I was thinking. The cable us protected from over load by the 16 Amp rcbo

 

[thestig246]

its possible i can see where your comming from, but what if everyone on the caravan decided to pull 16a on there van and would that not overload the cable?

 

[spark 68]

its possible i can see where your comming from, but what if everyone on the caravan decided to pull 16a on there van and would that not overload the cable?

well if it was limited to say 3 pitches per cable that would probably not overload, the (16A MCB/RCBO In X 1.45) X 3 off, it could possibly pull approx. 69 to 70 A for about an hour, but the chances of all 3 pitches pulling that amount together for that length of time would be slim I would have thought, it would have been interesting to see the original design criteria.

 

[Marvo]

I don't understand why they'd split off for each pitch at an underground joint or am I misunderstanding something?.

 

[atm84]

I don't understand why they'd split off for each pitch at an underground joint or am I misunderstanding something?.

I agree seems odd but may have been done to save cable. Instead of looping in and out at each point. Who knows

 

[davesparks]

I don't understand why they'd split off for each pitch at an underground joint or am I misunderstanding something?.

It is generally done to avoid bringing two large SWA cables up to each termination point if one smaller sized cable will suffice.

 

[Marvo]

I suppose the up side of doing it that way is you won't need any hi-tech equipment for fault finding, a spade and a hacksaw will suffice

 

[Engineer54]

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) :/

So now that you've found all these discrepancies on this caravan park what do you think will happen when you submit your Detailed Report??

That Hager board seems to be just a tiny tad over sized for the 5 breakers it's supplying, and with all that spare room, not a main isolating switch/breaker in sight!! In fact i'd go as far as to say, it's a made up panel from parts hanging around in a contractors stores... lol!!

 

[thestig246]

haha there is a main switch rcd bolted to the left hand side you cant see from photo, as its all TT. It is a big board but its allowing for future expantion ect theres another 30vans to come off it at some point in the future. There was some balls up if i rember right as everytime we had a powercut dad used to have to go down and turn a trip back on??? Thats why theres this different type of incomer bolted to the side apparently lol...

All of this has been signed off by two different NIC EIC assosiated members in past periodic s...

 

[Engineer54]

So what you're still confirming is, that this oversized panel/cabinets door can be opened without physically isolating the power within, so a code still applies does it not?? So still a ''Balls Up'' as you put it....

I suggest before they start adding additional caravans to this site they need to sort out the existing installations, because if what you have been describing is correct, this site's electrical installation is in a very sorry state of affairs, and why i asked, ''what do you think will happen when you submit your detailed report''...

Why do gullible people think that if it's been signed off by a NICEIC contractor/member it must be alright?? If anything, the opposite is usually the case these days!!

 

[Pete999]

[IMGhh][/IMG]

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..

If that's a SWA cable on the left, then the termination looks a bit mickey monk, don't you think?

 

[Bobster]

So what you're still confirming is, that this oversized panel/cabinets door can be opened without physically isolating the power within, so a code still applies does it not?? So still a ''Balls Up'' as you put it....

I suggest before they start adding additional caravans to this site they need to sort out the existing installations, because if what you have been describing is correct, this site's electrical installation is in a very sorry state of affairs, and why i asked, ''what do you think will happen when you submit your detailed report''...

Why do gullible people think that if it's been signed off by a NICEIC contractor/member it must be alright?? If anything, the opposite is usually the case these days!!

Not disagreeing with you on this system seeming to be a bit of a balls up, but most DB's can have the lid taken off without isolating. I know schneiders MCB/MCCB boards can be.

 

[Jonspark]

looks pretty much to me as though there's exposed live parts there

 

[Engineer54]

Not disagreeing with you on this system seeming to be a bit of a balls up, but most DB's can have the lid taken off without isolating. I know schneiders MCB/MCCB boards can be.

All our project DB/Panels are Schneider, (most of them with completely insulated bus bar and protected connection points), all have a cover capture 4 pole isolator switch, that only releases in the Off position. The panel in question here looks more of an add hock affair with exposed live conductive parts everywhere. Couple to that, this being a TT panel that seems accessable to caravan owners makes this even more of an issue that needs to be addressed....

 

[Engineer54]

If that's a SWA cable on the left, then the termination looks a bit mickey monk, don't you think?

Nah, it's fine Pete, the NICEIC have given it the all clear. ...lol!!