Is this bad?

[Burt_elliot]

I was doing a board change and the main neutral was to short to reach the terminal, I had a little bit of 25mm tails but had nothing to join it with so as a quick fix I joined the cable with a 63 amp mcb tucked at the bottom of the board and was going to replace it the next day? Do you think that would be ok or what would you have done in that situation?

 

[telectrix]

as long as it's only a temp. to get the power on. maybe extend the tail/s with henley blocks.

 

[sparks_114]

Connector block perhaps? With board changes one has to be careful and be kitted out, crimps, tails, sleeving, etc should all ideally be available. Given your situation I might've done the same if it was paramount for power to get back up.

 

[Burt_elliot]

Cheers chaps, it's just some people at work keep on abusing me because of it. But like you say it was only a temp because the hospital needed the power back on sharpish. I'm glad other people would of done the same in that situation

 

[RWJ]

I did a similar thing last week

Old Federal Electric Board, 32a MCB supplying all sockets to the Restaurant Kitchen gave up....
It tripped as soon as you reset it... Thought it was a problem on the circuit, but it did it with no power and with no circuits connected.

I couldn't get hold of any MCB's to fit the "stab lock" system so wired in a hager 32a and laid it in the bottom of the board.

Only issue is if the MCB trips it means a callout to reset.

 

[telectrix]

any temporary quick fix to get power back on is OK as long as it is SAFE, and only temp. IMO

 

[Bradzz]

Tune for you
YouTube - ‪masterchef synesthesia‬‏

 

[sparkinlee]

I agree that any safe temporary fix is OK. However, if I've understood you right you've connected the main neutral tail through a single pole MCB... if that MCB were to trip (which I guess is unlikely as it's rated at 63A) it would leave the live tail connected, and so you'd have an installation which appeared to be off (not-functioning) but live throughout - even the neutral bar in the CU would become live - so I'd question whether this is safe.

I'm very happy to be corrected if I've misunderstood!

 

[Burt_elliot]

Umm..... well that did happen but it was only because work sent me to a different job the the next week and I forgot about it, but would it be ok if I had fixed it the next day?

 

[Deleted member 26818]

You're bad, very bad.

 

[sparks_114]

One thing I notice in the electrical trade is that there is at times a conflict between trouble shooting (keeping the service going, not setting things straight) and inspection and testing (everything's got to be correct). Yes you managed to keep the power going but of course with a solution that is far from perfect. Often sparks argue around here on topics which are essentially to do with safety versus practicality. Classic ones being those that involve the DNO gear. I totally missed the fact that the MCB was on the neutral conductor, thanks sparkinlee for pointing it out. In honesty I think I would've done anything (withing reason) to keep it going other than that.

 

[RWJ]

I was doing a board change and the main neutral was to short to reach the terminal

I totally missed the fact that the MCB was on the neutral conductor

Me too!!

With that in mind I think a rated connector block would have been more suitable


I WOULD LIKE TO ADD... The MCB I talked about in my previous post was on the Line / Phase / Live side... Just replacing the MCB that wouldn't stay closed

 

[Burt_elliot]

Umm..... well that did happen but it was only because work sent me to a different job the the next week and I forgot about it, but would it be ok if I had fixed it the next day?

 

[sparks_114]

Umm..... well that did happen but it was only because work sent me to a different job the the next week and I forgot about it, but would it be ok if I had fixed it the next day?

I would say no. Too risky.

 

[Paul.M]

I'd say its ok for a temporary fix so you can shoot down to the wholesalers and pick up a henly connector, anything longer than that is a no no in my book.

 

[Burt_elliot]

Well I think if anything like that occurs again I'll just have to leave the power off, I just didn't want to let anyone down.

 

[JIGGSYMOO]

Well jigger me! an mcb should never be used in such a way

 

[Electro-tech]

During erection,connection of single pole devices for protection or switching in line conductor only.:66:

 

[Dunc]

Sounds potentially very dangerous to me regardless of being a quick and temporary fix. Get down the wholesalers and buy a couple of Henley blocks. If you keep a couple on your van at all times you'll be covered 99% of the time. I also carry through crimps at all times ranging from 1mm to 35mm as well as heat shrink for exactly these circumstances. Always better to be over prepared then under.

 

[Electricalserv]

Is your alias John Wayne in work?

 

[mayfair]

Your a very naughty boy electricalserv .....Henley blocks for sure

Is your alias John Wayne in work?

 

[sparc]

I had similar situation (slight too short tail) the other day, but had luxury of time to get a new longer tail. But I remember fitting a Hager CU a while back and using their tail kit option:

Hager Incoming Tails Kit by Hager

These connectors are a really nice size and - I'm guessing - must be 100A rated if Hager are selling them for meter tails. It's a shame you can't buy them separately - or can you? Anyone know please?

You can remove the little tails, btw.

 

[RWJ]

I had similar situation (slight too short tail) the other day, but had luxury of time to get a new longer tail. But I remember fitting a Hager CU a while back and using their tail kit option:

Hager Incoming Tails Kit by Hager

These connectors are a really nice size and - I'm guessing - must be 100A rated if Hager are selling them for meter tails. It's a shame you can't buy them separately - or can you? Anyone know please?
.

Isn't the link you posted Gillec selling the tails on their own for £11???

 

[sparc]

Correct - I meant can you buy just the connector blocks (which must be 100A rated) individually. They're much smaller than a Henley block.

 

[RWJ]

Correct - I meant can you buy just the connector blocks (which must be 100A rated) individually. They're much smaller than a Henley block.

Sorry misunderstood..... As per normal lol

Can't you buy 100a connector block.... I'm sure of it... 60a's quite standard

 

[nickblake]

Putting in a breaker on the neutral side no matter what size im my mind isnt correct ,there is a saying if in doubt dont do it , you work for a compay just a quick call saying you need a piece of tail would have been a better idea ,if it was refused you put your foot down and say you have to leave them no power , and a medical facility , if the breaker had tripped for any reason and there were any neutral to earth faults what do you think would happen !!
im sorry for being negative about this , just my opinion and im not having a go either

 

[SirKit Breaker]

I agree you gotta do what you gotta do to get outta the brown stuff. But the lesson is to be learned, as they say in the scouts BE PREPARED.

Cheers............Howard

 

[Paul.M]

Putting a breaker no matter what size im my mind isnt correct ,there is a saying if in doubt dont do it , you work for a compay just a quick call saying you need a piece of tail would have been a better idea ,if it was refused you put your foot down and say you have to leave them no power , and a medical facility , if the breaker had tripped for any reason and there were any neutral to earth faults what do you think would happen !! im sorry for being negative about this , just my opinion and im not having a go either

I don't think that your having a go at anyone and what you've said is spot on correct. Just as Sirkitbreaker has just said, if your in the brown sticky stuff you can bodge something together but in my opinion only for a short amount of time but not for a week like the op has said. Putting any form of fuse/mcb on a neutral by its self is very dodgy in the first place, but it sounds like the op wasn't prepared and unable to rectify the problem on the spot. You did the right thing but in the wrong way, take this as a lesson and move on, next time you will be better prepared. Don't take any of this as a personal insult. Electricalserv, play nicely .

 

[jonesyc894]

You should change the tails for new anyway to be fair, when doing a CU change.

 

[nickblake]

I agree you gotta do what you gotta do to get outta the brown stuff. But the lesson is to be learned, as they say in the scouts BE PREPARED.

Cheers............Howard

and when the job is done you can hop into your van and drive home singing gin gan gooly gooly gooly wonderfull:cool3:

 

[Paul.M]

 

[JD6400]

Now correct me if i am wrong but if this is a PME supply and this is the main board if you had lost the neutral your looking at mains potential earth bonds and metal work , especially if someone else had been a little slap happy on earthing arrangement .
And if it was a three phase installation earthing in place or not you would be looking at maybe 5-600 volts down one phase !
I have seen both scenarios and neither is good mojo , not having a go but if in doubt phone a Friend just to confirm your thoughts before you leave next time cause i think you may just have used up one of your life's , get out of jail free tokens.

 

[nickblake]

no because it needs the path from the cutout if you lost the neutral before the neutral / earth link at the cut out then yes you would and on three phase with the neutral missing you then have a potential 400 volts across light fittings etc however as i have stated in my post any neutral to earth shorts then this will back feed down to the earth bar and on to every earthed appliance potentially sticking volts on the earthed appliances , but as the supply is tied to earth where the neutral to earth fault is is where the whole installtion would run off and could possibly cause problems

 

[JD6400]

no because it needs the path from the cutout if you lost the neutral before the neutral / earth link at the cut out then yes you would and on three phase with the neutral missing you then have a potential 400 volts across light fittings etc however as i have stated in my post any neutral to earth shorts then this will back feed down to the earth bar and on to every earthed appliance potentially sticking volts on the earthed appliances , but as the supply is tied to earth where the neutral to earth fault is is where the whole installation would run off and could possibly cause problems

Hi Nick
Like i say i am open to correction , but you will get more than 400v .
We had one last year on a new supply , the meter installer had forgot to tighten the screws on the neutral load side of his meter and it as good as dropped out . We had 3 / 9kw 3ph electric boilers on it and it melted all the controls in them ( i think overall cost of around £ 17,000 ) but we were getting from 50 v to i am pretty sure 580v phase to earth .
I was only talking to a chap from UK Power Networks who installed the monitoring gear on one of our larger solar jobs on Wednesday morn about this and he confirmed this is not uncommon when there is a lost neutral on a three phase , he did explain the theory how but it was a little lost on me .

 

[JD6400]

Sorry Nick i forgot to say that i have reread op and paid little more attention this time and you are right on the PME bit .

 

[baldsparkies]

Saw the results of a loose neutral on a temp genny supply to an office block by the DNO.
Lots of fried single phase equipment.
The DNO operatives told us they have to pay for the damage because its such a common occurence they cant get insurance companies to under wright them !!!

 

[nickblake]

With a lost neutral on three phase that is befor the cut out there is literally no where for it to go so as what happens is you have say L 1 and L2 L3 through the MCB to the circuit and back to the common denominator which is the neutral bar , now due to their being a resistance across loads on the circuits it then back feeds up the phases blowing up any HF ballasts in circuit and due to the designe of switch starts they try and start up hence the flickering lights , also when this happens any earthed or extrainiouse parts that are bonded become live , one of the most common signes for a lost neutral is when you test across live and earth you will get a reading of around 120 volts and if you have a metal clad dist board its out with the gloves lol this problem occoures in TNCS systems hence there are lots of area's where TNCS systems are not permitted IE caravan hook ups so its intresting