MK sentry busbar configuration

[newtothis]

Personally I either use my Jr hacksaw or just mark one side with Snips, turn over mark the other side and then bend it back and forth until it snaps cleanly

Thanks for sharing your method. I snipped it and tapped it with a hammer it took less than a minute, TBH it has a little bit of a rough edge, I could file that and it would be like it was factory cut.
Is this attention to detail purely pride in good workmanship (I think that's important) or is there a safety/efficiency aspect to it ?

 

[Richard Burns]

Sharp points on metal that is carrying a charge will cause the concentration of that charge at these points.
In effect if there are sharp points a spark is more likely to cross the gap to another conductor.

 

[newtothis]

Sharp points on metal that is carrying a charge will cause the concentration of that charge at these points.
In effect if there are sharp points a spark is more likely to cross the gap to another conductor.

Getting my file out tommorow !

 

[newtothis]

Had to send my tester to megger due to a fault. This has delayed me fitting my CU.
I'm borrowing a 1720 later today.
Can anyone take a look at this layout and see if they think there's anything wrong.
Was thinking of putting the white F earth in circuit 1 with the circuit CPC
The neutral to the leftmost neutral terminal ?

 

[Richard Burns]

The arrangement you have there looks correct, I see you have the standard MK arrangement of slightly spread out MCBs a real nuisance to get the lid on, but nothing you can do about it!

As you are going for a hyper neat install it would be a good idea to get some ferrules and shorten the neutral and FE cables from the RCBO so that they can be dressed in neatly.
The first two 32A MCBs do not seem to be quite in place, but this may be just because of the initial set up and busbar absence.
Make sure the first neutral cable on the left cannot rise up and get trapped as the lid goes down.

As the board will not have any more neutrals in the left hand bar then I would move the neutral to beside the others, only for neatness.

I think the actual guidance for FE for RCBOs is that the FE is in a different terminal than the cpc so that if the cpc falls out there is still an earth reference for the RCBO, however this makes a right mess of wiring the board and I feel is a limited risk as the terminals will be correctly connected so I would do as you say and have the FE and cpc in terminal 1.
Though do be aware of the differences in clamping a ferrule end and a solid core in one terminal, if the ferrule end gets pushed to the side then the terminal may be tight on the solid core and loose on the ferrule. A potential solution is to ensure the ferrule is on top against the screw so it can spread and the two cores are crossed, but this is difficult to achieve so just ensure the cables are secure in the terminal.

Remember you will probably take all that lot out before you start wiring the board up so just ensure you get the cables back in the right places!
I like to have the circuit wiring above the main cables so that you can get to them for later modifications but many people have the main connections over the circuit wiring as it is easier to do. Just my personal preference.

 

[newtothis]

Thanks very much Richard,
Been finishing all preparatory work this morning, daren’t have the power off any longer, and it’s in a tight claustrophobic place.
So will fit tomorrow, think I’ve said tomorrow a few times.:drunk:

slightly spread out MCBs a real nuisance to get the lid on

I see what you mean.
They seem to be a nicer fit when the busbar is in, I will make a point of lining them up for the lid..

The first two 32A MCBs do not seem to be quite in place

Despite buying the MCBs MK recommend for the board.
The MK MCBs you buy separately are slightly different to the preloaded ones, the switches are higher about 3mm, see the two 6A MCBS to the left of RCD2.
That’s what’s making the 32A MCBs look dodgy.

I have to downgrade my aspirations from “hyper neat” to something a bit more realistic,
Neatish/not thrown in. Will have to have the ferrules poking out. I will have to practice my ferruling as I’ve never done it. Please tell me that’s not another 60 quid plus tool to add to my list ?:shocked:

I will attempt to hide the Neutral and FE from the RCBO, being careful not to clamp it at the back as you say.

I’ve had to extend all the cables, except one circuit, then I extended anyway just so it was all the same coloured wiring.

I have drilled holes in the floorboards and arranged so the cables come up on the applicable side of the board. Installs I’ve seen have the cables all bunched together. I wanted to avoid this is, then when my mate dropped off the tester, he told me it’s not actually worth the effort.

LOL costs & time are spiralling, the wife is making snide remarks, due to me saying it would be a quick n cheap job.

 

[Richard Burns]

Hey do not worry about it, it sounds like all CU installs, nothing goes right, the cables are the wrong length and the board wont sit straight; just get used to it! Think about all the experience you are gaining here, very valuable.

Being realistic is a sensible choice, this is what I would suggest is the best approach, a decent job without taking far too much time and no bodges, just adaptions!

Just remember there is lots of space behind the busbar for the excess cables as you have the cables on the right sides of the board you can have a sweep in from either side. Left cpcs grouped and brought over to the left hand side of the earth bar, right cpcs grouped and brought over to the right hand side of the busbar,then left hand neutrals and right hand neutrals to their bars and then spread out the lines to their respective breakers.

Good luck with it all and do not get discouraged, you haven't made a mess of it (yet)

MK are bad for easy fitting of the lid, it will go on eventually.
Ferrule crimps are a nuisance but very much useful for fine stranded cables in screw terminations. Any fine stranded cable should have a ferrule or the strands will just be cut by the screw or spread out and slip.
Do not worry the tool is not £60 it is only about £40-50!! and then you have to have a stock of ferrules.

You can actually get ratchet ferrule crimpers for about £10-20, purists will insist they be calibrated but unless you are doing it all the time just make sure they are securely crimped (I will get slapped for suggesting this is OK). Generally the best ones are hexagon crimpers but if you get the ratchet crimpers like the ones for butt crimps they are all right. A crimper with removable dies means that you can have one crimper for all different types of crimps and buy more dies as required.

 

[Bobster]

Ferrule crimps are a nuisance but very much useful for fine stranded cables in screw terminations. Any fine stranded cable should have a ferrule or the strands will just be cut by the screw or spread out and slip.

It's actually in the regs that fine stranded must be suitably terminated, which in effect means crimping or ferruling. Yes you can still tin the end, but then that's only for specific purposes.

The biggest reason they need ferruling/crimping is due to copper creep, over time the fine strands compact with change in temperature, thus the termination effectively becomes loose.
Do not worry the tool is not £60 it is only about £40-50!! and then you have to have a stock of ferrules.

You can actually get ratchet ferrule crimpers for about £10-20, purists will insist they be calibrated but unless you are doing it all the time just make sure they are securely crimped (I will get slapped for suggesting this is OK). Generally the best ones are hexagon crimpers but if you get the ratchet crimpers like the ones for butt crimps they are all right. A crimper with removable dies means that you can have one crimper for all different types of crimps and buy more dies as required.

Agreed, for the amount of work domestic lads will get out of a crimper, I wouldn't look at spending more than £30.

The only time I've ever required a calibration cert for crimpers is on the nuclear jobs I design. Other than that, you can check a ferrule has been crimped on properly by sight.

View attachment 31060

My comments in red.

 

[newtothis]

Thanks Fellas the advice is noted and will be taken on board.
Just for interest I'm posting a pic of the existing board. B&Q £40

To be fair I've never had a problem in 12 years, the RCD tripped once due to a problem with the oven.
And the MCBs protecting the lighting have tripped about 5 times when cheap bulbs have blown.

Has anyone got any comment on the way the tails go in to the existing board, is that much of a sweep desriable ? :blush5:

 

[Richard Burns]

I would usually say try and take the tails in as directly as possible.
The tails are normally in the way of running other cables so keeping them as out of the way as far as possible is often useful.
What is possibly the case in the above picture is that the tails came in from the left and when pushed into the board at an angle they came up to the right of a supporting pillar for the bus bar and so had to come round that as they came in to the switch.
I would have tried to get them to come straight up and then bend over to the switch terminals, but there is not a lot of room above the switch to fit in the bend when inserting them.

 

[newtothis]

The CU is in, prior to the install I identified had a little prob with the downstairs lights.
Which would have been a problem when it became RCD protected.
Apart from that, no dramas. Will post a pic tommorrow, I think with all the advice I've got you
deserve to see it, good or bad

 

[newtothis]

Here it is, I'm aware it's a bit rough, I will probably have a go at tidying it.
after tomorow's impending hangover fades.


Here's some excuses - it was my first ever CU install.
Here's a pic showing where I installed it. (See cupboard door mid bottom of pic)
Laying in there for 3 hours isn't ideal to say the least. :15:

 

[Leesparkykent]

Here it is, I'm aware it's a bit rough, I will probably have a go at tidying it.
after tomorow's impending hangover fades.
View attachment 31070

Here's some excuses - it was my first ever CU install.
Here's a pic showing where I installed it. (See cupboard door mid bottom of pic)
Laying in there for 3 hours isn't ideal to say the least. :15:
View attachment 31071

its not bad mate for your 1st board. no copper showing and all conductors in their correct terminal. I wouldn't worry to much about the aesthetics. put the cover on jobs a goodun

 

[Simonslimline]

Same as Lees comment here mate. The important thing is to take a lesson from it and see where you could of improved it etc. In my experience it takes a fair few before you start getting them how you want them to look.

It all comes down to practice and experience at the end of the day and thats it IMO.

Nice one and a Happy new year to you mate. unk:

 

[newtothis]

Thanks for the encouragement, I have to re-connect my outside lighting circuit so might me able to tidy.
It seemed to be going OK until I got to the RCBO

I have 3 weeks domestic guranteed starting Monday.
a shop, two 1 bed flats and a studio flat. all electric - no gas whatsover.
Ill only being labouring but, I'm sure I'll get loads of experience.

It was me who got the job in. I Heard about it from a mate, who knew what the developer had been quoted by another firm.
The price was way too high. I mentioned to another mate who got a firm involved
they agreed to take me on for the experience and a well decent ££££ earner. I'll just be getting on with the dogsbody stuff, won't be poking my nose in stuff I don't know about.

All the best to you for the new year mate.