Oil Leaking From Service Head

[Tim10]

There appears to be an oil like substance leaking from the intake side of our Service Head. I’ve uploaded some pictures to show you exactly what is happening.

The first picture shows our entire mains set up. The Service Head, a 100 amp Bill unit (the fuse inside is a 60 amp BS88) was put in when the house was built in 1968. The meter was replaced in 1989. I don’t know why, we got a letter from the then East Midlands Electricity Board telling us that they needed to replace the meter, which they did one Saturday morning. The consumer unit, originally a brown 4 way Wylex standard, was replaced last year.

The second picture is a more close up image of the Service Head, and the third shows a close up of the intake, where the leak can clearly be seen. Note the intake cable (PVC Concentric/Split Concentric I assume) appears shiny from the oil that’s gradually seeping down the cable.

The final picture shows the intake as it emerges from the floor. When I first saw this I thought it was water/damp coming from underneath the house, but it’s oil from the Service Head. This then travels down the cable under the house, where there’s the occasional drip on the basement floor.

The oil is black, not the green goo substance discussed in other posts on here. If I wipe the intake cable with a tissue, the colour is the same as when you wipe the oil from the dipstick in the car. It’s not gushing out, if I wipe the cable clean it’ll be another week or so before it collects on it again. The Service Head doesn’t get warm, and there’s no smell of burning or anything like that so I don’t think there’s any immediate danger. I’ve read about some older Service Heads filled with some form of bitumen compound. Was this done in the late 60’s, if so why? Could it be bitumen leaking from a Service Head of this age? If not, what is the likely cause?

Does anything need to be done to rectify the problem? If so, what is the urgency? How would it be remedied, by opening the unit and cleaning it out (NOT something I’m considering doing myself because it’s not my property and the obvious danger of unisolateable exposed live parts). Or would a new Service Head be needed?

Any advice or explanations would be gratefully appreciated.

Tim

 

[festa]

NO tim...
Call your DNO,local supplier or whoevers supplier name is on a bill,there should be no wet substances in that service head .
It may not be urgent but do you shouldn't take any chances my friend the service head belongs to the local DNO and is not yours to touch (anything upto your consumer unit/distribution board is the property of the DNO or supplier).
They shouldn't charge you for coming out to check it as it is their responsibility .

 

[baldelectrician]

Phone your REC emergency telephone number. This may be potentially dangerous.

Get them in to check it out.

 

[kai]

That looks like a PME service unit.

Out of interest, did they have TNCS supply feeds in the Sixties, or was that unit installed in 1989, when the meter was changed?

EDF energy are willing to fit a new service fuse holder for you, if yours is leaking oil onto the floor - Why on earth did they fill service fuses with oil in the olden days? it is messy and causes problems as shown earlier.

 

[Tim10]

Thanks very much for the replies so far.

NO tim...
Call your DNO,local supplier or whoevers supplier name is on a bill,there should be no wet substances in that service head .
It may not be urgent but do you shouldn't take any chances my friend the service head belongs to the local DNO and is not yours to touch (anything upto your consumer unit/distribution board is the property of the DNO or supplier).
They shouldn't charge you for coming out to check it as it is their responsibility .

I never had any intention of touching this myself, no worries about that! I have a good knowledge of domestic electrical systems. I was an apprentice electrician when I left school, although I didn't complete the apprentiship due to being made redundant by my employer. If oil were leaking from any of our electrical apperatus I would have isolated it, investigated, then carried out the necessary repairs/replacement. But wouldn't contemplate opening a live cutout!!!

I've never come across anything like this before, so thought someone here could shed some light on what exactly it is and what has caused it.

That looks like a PME service unit.

Out of interest, did they have TNCS supply feeds in the Sixties, or was that unit installed in 1989, when the meter was changed?

Only the meter was replaced in 1989, the cutout is the original unit installed when the house was built 39 years ago. I watched the guy from East Midlands Electricity change the meter, he didn't touch the cutout, apart from to remove the service fuse. At the time I was just starting to learn so it was an interesting experience.

I've always assumed it's a TNCS supply, but pictures posted on here recently of an apparently PME service head showed that it was infact a TNS supply when opened. The neutral link wasn't fitted to the earth, and the earth and neutral were wired separately into the split concentric supply cable. I'm not going to open our unit up to see how it's wired!

EDF energy are willing to fit a new service fuse holder for you, if yours is leaking oil onto the floor - Why on earth did they fill service fuses with oil in the olden days? it is messy and causes problems as shown earlier.

Would they completely replace the cutout if we asked (which would be better) or just clean it out? I can only imagine that the cutout was filled with oil for insulation purposes (I'm just guessing here?) and the seal at the bottom has gone allowing it to seap out?

Phone your REC emergency telephone number. This may be potentially dangerous.

Get them in to check it out.

That's what I'm hoping to do. The only slight problem is this is actually my parent's house, and when I first pointed out to my Dad that there was an oil leak that I couldn't do anything about myself, he was very reluctant to get someone in to have a look incase they either charge the earth to fix it or try and tell us we need a whole lot of other expensive work doing. I know the DNO are responsible for this kit so SHOULDN'T charge us for it, but at the time I didn't push the matter. This was about 6 months ago. I was hoping that the leak would fix itself over time, which hasn't happened, so I thought it was time to try and find out what the likely cause is, what the potential hazzards, if any, are, with a view to saying this has got to be sorted out now!

I've no idea how long the cutout has been leaking oil. It's at least a year, but could be several years as it's in the bottom of a cupboard which was piled high with junk that I only cleared out last year.

So what I really need is information and/or advice on the likely causes, potential hazzards and any other information so if I need to I can confront my Dad and tell him that this needs to be fixed!

Cheers

Tim

 

[securespark]

Yes! PME was first installed in the 60's- in my experience, the oldest PME I've found was installed in 1966. Whether they started then or before, I don't know.

 

[Tim10]

Yes! PME was first installed in the 60's- in my experience, the oldest PME I've found was installed in 1966. Whether they started then or before, I don't know.

That makes sense as 1966 would co-incide with the publication of the fourteenth edition. Maybe this was where PME supplies were first introduced?

Was there ever any regulation requiring cutouts be filled with oil, and/or subsequent later regulation banning this because of the kind of problem we're experiencing?

Tim

 

[securespark]

I've just looked in my first edition of the 14th (pub. 1/10/66) and PME is mentioned, so it was certainly in existence then.

By contrast, my estate, built commencing 1960, has purely TN-S supplies.

 

[jondiy]

Dunno if its worth mentioning, but according to that meter pic, the max current it can handle is 40 amps! - very meagre by todays standards!

If your cutout has a 40A fuse you should be ok, but if it has been uprated, then I'm not sure how meters cope with overcurrents!! (Wonder if the max meterable load is 40A - in this case you could be saving on electricity costs , or the max contact ratings are 40A - in this case be worried as potential fire hazard )

Anybody have any views on this?

 

[securespark]

If it is a 40A meter, it is most probably >20 years old. The DNO's are supposed to renew meters on a 20Yr cycle, so ring em up & tell em you plan to fit additional loads (high power shower, cooker etc) and want their side to be modernised (ie 100a fuse & meter & tails).

 

[Tim10]

Dunno if its worth mentioning, but according to that meter pic, the max current it can handle is 40 amps! - very meagre by todays standards!

If your cutout has a 40A fuse you should be ok, but if it has been uprated, then I'm not sure how meters cope with overcurrents!! (Wonder if the max meterable load is 40A - in this case you could be saving on electricity costs , or the max contact ratings are 40A - in this case be worried as potential fire hazard )

Anybody have any views on this?

The cutout fuse is a BS88 rated at 60 amps. It's always been 60 amps, we've never had it changed, so it seems strange that the meter is only rated at 40 amps max?

I've calculated that under heavy load, we could potentially be using as much as 60-70 amps for short periods (not exceeding a few minutes at a time) although there shouldn't be a consistent load over 40 amps over a longer period. I don't know if this poses any danger?

If it is a 40A meter, it is most probably >20 years old. The DNO's are supposed to renew meters on a 20Yr cycle,

This meter was installed in April 1989, so almost 18 years ago. The 20 year cycle makes sense because it replaced what I assume was the original meter installed when the house was built in 1968, which would have been 21 years old.

But, I strongly suspect that the meter wasn't new in 1989 because the dials weren't at 0 when it was installed, so I've always thought that it may have done 20 odd years service in another property, been taken out, tested and calibration checked before been given to us. This meter was a virtual like for like replacement of the original meter meaning it could potentially be 40 years old.

Do/did the DNO recycle meters like this?

so ring em up & tell em you plan to fit additional loads (high power shower, cooker etc) and want their side to be modernised (ie 100a fuse & meter & tails).

I had noticed a while back that the meter was only rated at 40 amps, but thought I'd not bring it up unless we were planning on installing any power hungry appliances. We only have a small cooker and the shower runs from the hot water. If we get an electric shower at some point in the future, that could easily add another 40 amps to the total load meaning we could potentially be pulling in over 100 amps for brief periods which is clearly well over the rating of the meter and could even put the service fuse in danger of blowing!

If we decide to install anything that will increase the total load, I'll request a fuse/tails upgrade beforehand. I guess the meter must be coming up for renewall in 2-3 years time anyway.

The oil leak from the cutout is worrying me alot more at the moment. If we get that sorted out/changed I'll enquire about a tails/meter upgrade then.

Tim