Two submains from meter

[gmal]

Hi,
The property in question has it's meter box on a garden wall in which there is:
100A cutout --> Meter (Rated at 80A) --> Isolator --> Henleys --> Two 60A fused isolators. Each fused isolator supplies an SWA submain, one to a house, the other to a workshop.
My question is shouldn't there be some form of protection for the meter if, for example, each submain started drawing 50A?
Many thanks,
Guy

 

[shanky887614]

how do you know the cutout is 100amp?

just because it says 100 on the outside doesnt mean its got a 100amp fuse fitted.

besides its the suppliers property so not your problem if it blows up its there fault for not protecting there own equipment

 

[Resu]

What's in place to protect the meter in any domestic property? No matter how this was wired (workshop fed from house D.B or any other way) they could still potentially pull your theoretical combined 100A!

 

[gmal]

I was thinking that if it wasn't for the workshop there would only be one submain from the meter. In which case the meter would be protected by the 80a fused isolator and 63a main switch in the consumer unit. But with the workshop there are two CU's wired in parallel with henleys after the meter so it is possible for an over-current of the meter. Should there be an MCB between the meter and the henleys do you think?

 

[Knobhead]

Meters and cutouts are out of your remit so leave the bloody things alone!

How do you know it’s a 100A cutout?

 

[Rockingit]

In my experience around here which is WPD, the cut outs all have 80A fuses in them specifically BECAUSE the meters are only rated at 80A also. Several DNO peeps have told me that now.

 

[gmal]

OK thanks everyone I will leave it be! I was never going to be touching them anyway as im not an electrician, but in the near future a CNC router will be installed in the workshop and I wanted to make sure everything was up to scratch.

 

[Silly Sausage]

In my experience around here which is WPD, the cut outs all have 80A fuses in them specifically BECAUSE the meters are only rated at 80A also. Several DNO peeps have told me that now.

When we had our meter changed a few years ago, the meterman asked me how long had the fuse been bypassed with several bits of fuse wire.
No idea says I with a shrug of the shoulders. It was my 'temporary' fix with 3 bits of 30A fuse wire after it eventually got blown out from a series of shorts on the downstairs RFC. Trashed that cable



edit: he used an 80A fuse for the 80A meter, including an 80A fuse label (just for Eng! )

 

[Engineer54]

In my experience around here which is WPD, the cut outs all have 80A fuses in them specifically BECAUSE the meters are only rated at 80A also. Several DNO peeps have told me that now.

Another good reason, is that the DNO's Ze value does not comply with a BS 88/1361 100A fuse!!

 

[Knobhead]

I’ve an 80A meter with a 100A fuse in the service head. A bit daft for a one bedroom flat!

Years ago, I had a senior engineer from NWEB kick my arse for uprating the 30A cut-out to a 60A.
The EMEB used Lucy cut-outs, pity the NWEB didn’t. It gave the game away. It had all the seals on the meter and head, they were EMEB as well.

A month later NWEB installed new OH lines to the road and new cut-outs at each house. Everyone on the road got a 60A service, I got100A. (Legitimately this time!) The engineer had become a friend so stings were pulled.

The house as bought had a single 15A and two 5A sockets so a 30A cut-out was ample.

 

[Silly Sausage]

I’ve an 80A meter with a 100A fuse in the service head. A bit daft for a one bedroom flat!

I don't know, what with some of yours and the Minx's interests! :wink_smile::love:

 

[Knobhead]

Tesla coils and wands don’t need that much power!

 

[7029 dave]

Some of the old dial meters are only 40amp.:stooge_curly:

 

[gmal]

I've also been looking at the earthing arrangement and would appreciate if you chaps could confirm its suitability. The cutout has a PME sticker on it from which the earth is connected to the armour of the SWA for both submains. However earth rods are installed at the house and workshop. At the house CU the SWA armour is earthed again and therefore connecting it the earth rod, is this correct? Shouldn't the PME earth be isolated from circuits earthed using a rod?

 

[Knobhead]

Are you actually an electrician?

 

[Simonslimline]

Are you actually an electrician?

See post 7.