Identify the cut out.

[Bolty]

Heres a piccy from my cut out. Any idea on when these came into and out of service?

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• Bolty
• 28 Jan 2012
• 1

Its a metal clad isco type and i'm in the process of trying to get my dno (SSE) to swap it out before i change the old wylex rewirable cu. The small looped green wire (4mm2) at the side is the main earth but i cannot trace its origin yet. (theres a good earth reading and the sub station is approx 250 yards away).

Any one got any good ammunition i can use the get the dno out to look at the cut out?. Hopefully i can get it done FOC.

Bolty.

 

[riveralt]

It looks like both the live and neutral are fused - don't think DNO's like fused neutrals???

 

[Wontdothatagain]

Any one got any good ammunition i can use the get the dno out to look at the cut out?. Hopefully i can get it done FOC.

You can ask the DNO to look at it explaining that you have some concerns about its age and condition but they will probably tell you that it is fine as it is. DNO's will not change equipment unless it is unsafe or has been deemed unfit for continued servise.

DO NOT TRY TO ENTER THIS UNIT YOURSELF. IT IS A CAST IRON UNIT AND IF YOU MAKE A MISTAKE, IT WILL GO UP LIKE A ROMAN CANDLE

The neutral is usualy just a block of copper inside or on the latter ones a link bar

 

[Bolty]

Don't panic - i've no deathwish to attempt to open this one up!.

In my day to day work working within the water industry, we're forbidden from touching any cast iron cut outs and usually get them changed out but as this is a domestic case (mine), i'm a little unsure of the best path to take or associated costs.

a little ammo can go a long way though "cough...hmmm its maybe a fused neutral type"

Bolty

 

[Wontdothatagain]

It will cost you nothing to get them to come and look at it but bare in mind, it will not be clasified as an emergency job and SSE's wating time is about 4 weeks at the moment.

Just say "my cutout is getting very warm when i have only a little load on it". That may get them out a little faster.

I came accross this the other day (which is a 3 phase version of yours) whilst on a debt disconnection. SSE said it was fine and refused to change it

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• Wontdothatagain
• 28 Jan 2012
• 1

 

[westie101]

I/we wouldn't hesitate to change either of them!!

Report it as a smell of burning or that you can see exposed copper !

 

[RF Lighting]

My DNO will change those cutouts if you ask for an increased supply capacity, but it's a chargeable job for them.

 

[gazfen]

They Want Changing them two Cutouts Asbestos Inside Meter Fixers Dont Work On Them , Tell Them Its Getting Warm and you can smell Burnng

 

[Guitarguy]

I changed two of these cast iron type cutouts last week, one was split phase the other single Phase. I doubt the neutral is fused on the first pic as it would have two fuse holders that's got a neutral block, the dno should change them though, they've done their time. meter fitters tend to s**t themselves at the sight and the terminals tend to be too small to accept 25mm tail

 

[Bolty]

Thanks for the responses.

I agree the cut out is pretty much past its best by date but i suspect this job will be a bit more of a hassle to change as there isnt any pull on the cable as it appears to be plastered into the wall, so unless the henley cut out or whatever they fit will be a direct replacement, it looks like it'll cost me

To make matters much, after a dig under the house to suss out cable runs etc for the downstairs rewire, it appears the main earth is from my friendly mains water pipe! . Double checking the earth loop impedance readings gives me better than acceptable values for all the circuits (bs3036) but another hassle to sort out.

Hopefully if i can get the cut out replaced, a bit of tea and biccys can get the earthing changed to tn-s or tncs if possible. If not, TT supply, here we come.

(Are single pole rcbo's acceptable for TT or is dp rcbo's still the general choice?... all upstream of a 100a 100ma time delay rcd. I'd better get ready just incase)

Thanks
Bolty.

 

[flameport]

(Are single pole rcbo's acceptable for TT or is dp rcbo's still the general choice?... all upstream of a 100a 100ma time delay rcd. I'd better get ready just incase)

Single pole RCBOs and a 100mA RCD incomer are no use, since the RCBO won't disconnect the neutral - meaning a neutral-earth fault anywhere will still cause the whole installation to be disconnected until the fault is found.

Double pole RCBOs are fine, but there is no point in having a 100mA incomer with those unless your consumer unit is metal cased, which you wouldn't normally want for a TT supply anyway.

Or a dual RCD board fitted with MCBs - just as many TN installations would have.