Service Head scenario

[Kingston555]

Hi, I'm a trainee electrician and am thinking about upgrading a consumer unit. I'm aware that anything south of the CCU belongs to the electricity supplier and that we're required to call them out to remove the fuse from the service head before starting such a job; but I'm curious about this scenario because both the Line and Neutral cables are going into their own separate Henley blocks, before carrying on to the meter. Would these Henley blocks have removable fuses then? I thought Henley blocks were just simple connection blocks.

 

[Marvo]

You posted this in the Trainee Forum application are which means only you and the forum staff could see it. I've moved it to the General Electrical forum for you.

What training are you currently doing? What test equipment do you have?

 

[davesparks]

If you are an apprentice then you really shouldn't attempt these jobs until your mentor is happy that you are safe to do them.

 

[Leesparkykent]

Hi, I'm a trainee electrician and am thinking about upgrading a consumer unit. I'm aware that anything south of the CCU belongs to the electricity supplier and that we're required to call them out to remove the fuse from the service head before starting such a job; but I'm curious about this scenario because both the Line and Neutral cables are going into their own separate Henley blocks, before carrying on to the meter. Would these Henley blocks have removable fuses then? I thought Henley blocks were just simple connection blocks.

Henley blocks do not have fuses in them they are generally used for connecting multiple tails together. You should be doing this job under direct supervision from a qualified electrician and shouldn't be thinking of tackling this yourself. Changing a consumer units is also notifiable.

just for your reference this is a Henley block.

 

[trev]

Hi, I'm a trainee electrician and am thinking about upgrading a consumer unit.

OI! KINGSTON! NOOOOOOO!
Seriously mate, you're a trainee. Are you really ready to fly solo? From your question I'd guess not quite mate. Henleys are just connection blocks and unless the fuse is removed then they're going to be full of juice and waiting to bite you.
As Marvo said, do you have / have access to proper test gear? You're going to need it for both the pre change tests and the post change ones.
Do you know how to interpret the results it gives you? If you don't then you'll be relying on the bang test.
Obviously I have no idea what stage you're at in your training but you might be better off doing this under supervision. I'm sorry if this sounds patronising, it is not my intention, but please think carefully before you do this as there's a good few problems that you might not know about just waiting for you in the old wiring.
You mention that you're thinking of doing this, is there any particular reason or is it just because it's there?

 

[rapparee]

Henley blocks like the one above are not fused.

Edit: lee and trev have beaten me to it. I spent too long browsing for the image

 

[telectrix]

Henley blocks like the one above are not fused.

Edit: lee and trev have beaten me to it. I spent too long browsing for the image

looking for your guinness, more like. :49:

 

[Resu]

Hi, I'm a trainee electrician and am thinking about upgrading a consumer unit. I'm aware that anything south of the CCU belongs to the electricity supplier and that we're required to call them out to remove the fuse from the service head before starting such a job; but I'm curious about this scenario because both the Line and Neutral cables are going into their own separate Henley blocks, before carrying on to the meter. Would these Henley blocks have removable fuses then? I thought Henley blocks were just simple connection blocks.

CU not CCU (cooker conection unit!)
And it's the stuff North of the meter that belongs to the supplier!

 

[telectrix]

and the meter.

 

[Kingston555]

Thanks for all the feedback...and I'm stepping away from the board! The existing CU is a bit dated but still does the job fine, I just thought it would be a straightforward first job to try my hand at. Having read the thread though, I won't be touching it . I guess my trouble is that unless I start attempting some simple stuff myself to start with (albeit not this job), I'm wondering where I'm going to gain the experience from. I've asked a couple of local electricians if I can help out as and when but no joy. I've recently done the following City & Guilds:
1) Electrical Installation within a Domestic Dwelling (4141-01)
2) Part P Building Regs (2393)
3) Inspection & Testing (2392-10)

So, yes, very early days for me.

 

[ImpededLoop]

CU not CCU (cooker conection unit!)
And it's the stuff North of the meter that belongs to the supplier!

Unfortunately in City and Guilds speak, CCU is correct. I think it stands for consumers control unit.

I agree that it can be confused with the cooker switch, but I thought I should highlight this so we don't mislead any trainees reading this.

 

[GMES]

Kingston the lads have done the right thing by advising you against taking this on for your 1st job. At first it may look a straight forward job but it can be a nightmare if you don't understand all aspects of the job, borrowed neutrals is just one issue than cause a huge headache unless you are experienced.

We get people coming on here claiming to be fully qualified electricians who have swapped a board out and have ended up with tripping rcd's etc and end up in a right mess.

If you haven't done so already pop into this section Electricians Unite - Jobs In Your Area - Electricians Forums and ask if anyone is willing to give you a few days experience I'm sure there must be a couple of members who are located near you and might just be willing to let you jump onto a board change with them if I were near you I certainly would.

Also thanks guys for steering him in the right direction.

 

[Kingston555]

Thanks again! Sounds as though my eagerness would've got me into a very big mess.

 

[Resu]

Unfortunately in City and Guilds speak, CCU is correct. I think it stands for consumers control unit.

I agree that it can be confused with the cooker switch, but I thought I should highlight this so we don't mislead any trainees reading this.

Ah sorry, I'm in Scotland so all SECTT courses.

 

[shanky887614]

if you ever the both tails going through a fuse holder be very careful, some of the old supply heads are dangerous and the dno's will replace them on notification.

i wouldn't touch any that doesnt look in good condition.

take picture's mate and post them.

your always better showing someone a picture when asking there advice rather than try to explain it,if it is actually a fuseholder for the neutrel (with a link or fuse) chances are it could be an old dc head

(from a quick google fused neutrals were allowed up until the 50's on ac incomers)

late break early make isolators are allowed though, fuses are not because if the N blows then you could be there a while getting shocked because of the nature of ac