New Consumer Unit Help

[andemz]

Just got my MK sentry consumer unit today. The instructions were not very helpful and i've read them over and over. I've got a few pics as can be seen below for clarification. 100A main switch RCD 80A 30mA, 12 breakers 5x 6mcbs, 2x 16mcbs and 5x 32mcbs.

Question 1) Although i've only got 12 MCB's from the pic it states 16 holes so i take it it's got 16 useable ways so that if i needed i could add extra MCB's.

Question 2) If you look at top right of the earth bar you will see the number 16 and then 3 extra holes 1 has the earth mark and the other 2 state underneath the word Bond. Would you use the 2 holes for the bond or just the 1?

Question 3) Is the buzz bar in the correct place and what is a buzz bar for?

Question 4) you will see that where my finger is pointed there is a hole on the top of the breaker does this take the live and the hole on the bottom takes the other live if on a ring circuit or do both wires if on a ring go into the same hole. If it were on a radial then you wouldn't have an incoming live back into the breaker.

I do have the front cover etc and it is really nice. I guess this is another part in the learning but i will get a sparky to come and fit this in when we are ready.
Thanks for your time if you have read it or responded insome way.

 

[securespark]

Looking at the busbar, there are 15 "prongs" on it, not 16. There are 16 ways on the neutral and earth blocks, but this is probably for a bigger unit.

1-8 on the left hand neutral block are for the neutrals from the circuits you wire on the NON protected side of the CU.

The r/h/s neutral block is for the RCD protected circuits.

On the earth block, the E symbol is for the incoming earth from the MET.

The others are for main bonding conductors. Those can be connected to these terminals (ie gas, water etc) Or if there is space, they can be connected to the MET.

I'm a bit worried now. You're not sure what a busbar is and not sure how the mcb's are connected up to the unit and to the circuits.

Your idea of how to do it is wildly off the mark, and with all respect, suggest you get a spark to do the work for you. You don't want to do any work substandard and risk fire, injury or death do you?

 

[andemz]

I guess this is another part in the learning but i will get a sparky to come and fit this in when we are ready.

SS you are right, i don't know what a busbar is and as you stated i don't know how to wire up the mcb's. That's why i stated the above in my post. I do however want to learn and examine the consumer unit and mcb's. I must admit since i've been on this forum i've acquired an immense amount of knowledge about electrics and will continue to do so with posts like this one!

 

[Millennium_Boy]

You must get a qualified sparky in to install it for you, and issue you an Installation Certificate.

It is evident you are unsure as how to proceed safely.

 

[andemz]

You must get a qualified sparky in to install it for you, and issue you an Installation Certificate.

It is evident you are unsure as how to proceed safely.

Thanks for repeating what SS has stated in his post for this i refer to my previous post!!!

It's only knowledge that i am asking for. I AM NOT DOING THIS MYSELF (I AM NOT COMPETENT ENOUGH)

Having said that i am still looking for answers to my questions as stated in my previous post.

Thanks

 

[ban-all-sheds]

Question 1) Although i've only got 12 MCB's from the pic it states 16 holes so i take it it's got 16 useable ways so that if i needed i could add extra MCB's.

In a 16-way split load board you only have room for 12 MCBs, as you lose 2 spaces for the main switch and 2 for the RCD.

Question 3) Is the buzz bar in the correct place and what is a buzz bar for?

A buzz bar is to make the CU buzz - see //www.diynot.com/forums/viewtopic.php?t=11715

A busbar on the other hand is a large, thick, usually uninsulated, rigid metal bar or rod which is used within equipment or switchgear etc to carry high currents.

In a CU it connects together the output of the main switch and the input of all the MCBs. I'm sure that Laine won't mind you looking at his:

Question 4) you will see that where my finger is pointed there is a hole on the top of the breaker does this take the live and the hole on the bottom takes the other live if on a ring circuit or do both wires if on a ring go into the same hole.

Now just think logically for a second - if you have only two terminals on an MCB, and you connect one end of the ring to one, and the other end to the other, how does the supply get connected?

I do have the front cover etc and it is really nice.

Actually, I think they're a bit shabby - switches and MCBs are one thing, but if you think what you pay for a bare naked CU, and what you actually get - a cheap plastic moulding, a bit of DIN rail and a few terminal blocks, I think the price is outrageous, particularly as you can't get the MCBs to sit upright. And a busbar cover would be nice. MK used to be top notch, and although their accessories are still good, they seem to be losing the plot with CUs.

 

[securespark]

They are shabby- I installed my first (and last!!!) MK unit a few months ago.

Getting the mcb's to sit upright is IMPOSSIBLE - I have challenged MK Tech to come on site with me and show me how it is done.

Other mfrs screw their 'bars down. Then there is limited movement when tightening up the mcbs.

Glad to see Laine's mcbs are looking like TLTOP.....!

Some of the accessories Ban are shoddy. Like the roses & 3 plate battens: the lampholders are 5H.

As I said in a previous post, I can pick up the same make (MK buy them in) of either from Denmans for 79 - 89p each.

Penny pinching gone the same way with the CU's it seems.

Trouble was in the 70's & 80's, MK were sitting pretty, but now have been forced to make the infamous 20% price cut, and quality has suffered hugely as a result.

The old range of MK lampholders was made by DeltaMEM, solid quality piece of kit - last for ever.

I installed two new style MK pendants for a customer who was mistaken in his loyalty for MK (I offered him MEM as the equivalent of old MK, but he refused). Have now changed them both four times under MK's warranty (10/15 years?) since 1998. They are the laughing stock....

Very Greedy. Instead of cutting back on profits a little, all their compromise has gone into cheap sh*t products that are so flimsy. Great marketing ploy, MK............

 

[ban-all-sheds]

They are shabby- I installed my first (and last!!!) MK unit a few months ago......

And you now favour.........?

 

[andemz]

Thanks for the replies all. just to confirm i do have a busbar cover and obviously a front cover.

I now understand the busbar, but Laine's seems to be fitted a bit different in his pic compared to mine. His seems to be standing up and mine seems to be laying flat. Are they fitted differently in different consumer units?

I suppose you guys who are fitting these things day in and day out are really the only ones who can comment on the quality of these units. For me however it appears a good unit for domestic use adn this will be fitted by a sparky.

Now just think logically for a second - if you have only two terminals on an MCB, and you connect one end of the ring to one, and the other end to the other, how does the supply get connected?

Fair point... what is the hole on the bottom for then as there is on on the top and one on the bottom. I can see from Laine's CU that the live feed is coming from the top, can't see what's happening on the bottom though!

 

[ban-all-sheds]

No - what you can see in the photo is the live feed going into the bottom terminals, via the busbar, and all the circuit cables connected to the top terminals.

Wise you are an electrician to get.