Question on connecting up 2nd consumer unit

[sambuca2907]

Hi all - just wondering if I could get some advice.

I have installed 3 new circuits in an extension - a kitchen - lighting, ring main and cooker (gas so just 13A elec start). The existing board only contains MCB's, and my new circuits need to comply with 17th edition regs, so need RCD protection throughout.

The existing board is a nightmare... the electrics in the house I have come across are condemable so I have no wish what-so-ever to touch these! The guy who lives in the house "did a bit of electrics" years ago... so has done his own additions over the last 25 years...! I took the cover off a light fitting and found SIX lots of 1.5mm going into this... mangled together with choc-blocs and tape!! If I replace the existing board I just know I'm going to have earth leakage everywhere and never find the problems, so going towards putting in a new 17th edition board to cover the new circuits.

The question I'm asking is do you think it's better to do the following:

- Run 6mm from a 45A MCB in the existing board to the new board, and link back to the main earth terminal (Distribution circuit)

- Remove the tails from the existing board, add in Henley boxes and run a new set of tails to BOTH boards... abviously this option is going to cost more which I'm reluctant against as I've already priced for the job without this in mind!

Any help please?!

 

[Spudnik]

I found that one, but it doesnt say that every CU needs to be switched at once.

There could be 2 installations in one dwelling.

Must admit i have never fitted a separate main switch for 2 CU's.

One isnt needed when there is off peak CU in place.

Not splitting hairs but there is no point in doing extra work when not needed!!!

 

[sparks1234]

I found that one, but it doesnt say that every CU needs to be switched at once.

There could be 2 installations in one dwelling.

Must admit i have never fitted a separate main switch for 2 CU's.

One isnt needed when there is off peak CU in place.

Not splitting hairs but there is no point in doing extra work when not needed!!!

Its something I have taken up with the ECA as well and there should only be one main switch for an installation, I do take your point on the off peak supplies and I think it is one that escapes the rule.

There could well be 2 dwellings in one building or indeed 2 office suite in one building, each suite or dwelling ie flat in a large house should have a main switch

There was also an argument about stating the company fuses can be called the single point of isolation but that doesnt carry the can

The regulation says a main linked switch, that would also in my mind say a main switch for the installation being the MAIN switch

 

[Sintra]

I found that one, but it doesnt say that every CU needs to be switched at once.

There could be 2 installations in one dwelling.

Must admit i have never fitted a separate main switch for 2 CU's.

One isnt needed when there is off peak CU in place.

Not splitting hairs but there is no point in doing extra work when not needed!!!

What is the definition of an installation? I was under the impression that an installation was everything downstream from the supply authority meter.

The Reg also states a main switch which indicates 1.

No point in extra work if not needed but if i install henleys i would always install main switch to isolate the full installation. By the way got pulled up on it years ago during an NIC assessment so have done it since.

 

[sparks1234]

What is the definition of an installation? I was under the impression that an installation was everything downstream from the supply authority meter.

The Reg also states a main switch which indicates 1.

No point in extra work if not needed but if i install henleys i would always install main switch to isolate the full installation. By the way got pulled up on it years ago during an NIC assessment so have done it since.

NIC

 

[Spudnik]

Funny you should say that as i asked my assessor just last week about this.

He said that the installation work YOU do (eg sep cu) must have a single point of isolation, which would be the main switch for the CU that you have just installed.

Therefore, you would then have 2 installations in one building, with a main switch for each installation.

 

[sparks1234]

Funny you should say that as i asked my assessor just last week about this.

He said that the installation work YOU do (eg sep cu) must have a single point of isolation, which would be the main switch for the CU that you have just installed.

Therefore, you would then have 2 installations in one building, with a main switch for each installation.

So, just to clarify, if you install additional additional circuits in one office suite and you need to install extra dis board you are calling that 2 installations or are you saying you have say a 2 story building with 2 office suites each with own installation and thats 2 installations

 

[drywax]

Sorry to hi jack this thread but whilst talking about main switches if there isn't one between the meter and the henley block would a qualified sparky be able to remove the main fuse and fit one or would this be a job for the electric supplier as most mains fuses have a little security wire attached. Who would be liable?

 

[Spudnik]

Yes to both

For eg.

Kitchen extension, new rfc, cooker radial lighting. No room in existing. Customer wont pay for bigger.

Install stand alone CU for your installation, which is separate but in the building/dwelling.

Sorry to hi jack this thread but whilst talking about main switches if there isn't one between the meter and the henley block would a qualified sparky be able to remove the main fuse and fit one or would this be a job for the electric supplier as most mains fuses have a little security wire attached. Who would be liable?

You might want to start a separate thread for that.

Make sure you wear your tin hat

 

[sparks1234]

Sorry to hi jack this thread but whilst talking about main switches if there isn't one between the meter and the henley block would a qualified sparky be able to remove the main fuse and fit one or would this be a job for the electric supplier as most mains fuses have a little security wire attached. Who would be liable?

Most sparks havent got time or the patience to wait that long for the board and most would do it them selves, it is a matter of contention at the moment as the leccy boards dont want us untrained persons to remove the cutout fuse but life is too short, besides it was an emergency...wasnt it??

Yes to both

For eg.

Kitchen extension, new rfc, cooker radial lighting. No room in existing. Customer wont pay for bigger.

Install stand alone CU for your installation, which is separate but in the building/dwelling.



You might want to start a separate thread for that.

Make sure you wear your tin hat

are you the one and only "super" moderator?

 

[Spudnik]

are you the one and only "super" moderator?

errr.... yes.......but why??

 

[solo2771]

makes sence to me to have single main switch. if you didn't and someone didn't know about cu2 and isolated cu1 thinking whole installation dead they might get a suprise and some cu's are well hidden.

 

[ajelec10]

I knew it was some thing like that, how did you find installing it? the REC25 i mean?

 

[sparks1234]

I knew it was some thing like that, how did you find installing it? the REC25 i mean?

Its still in the back of the van ...so far so good then

errr.... yes.......but why??

Just askin

 

[Amp David]

Yep, bought one today

How much did you pay?

Is it a Wylex REC2S?

 

[sparks1234]

How much did you pay?

Is it a Wylex REC2S?

Wont get the invoice for a couple of weeks so....dont know