High Resistance on Power Sockets

Enterprise_1701C

Our electric circuit is the old style, with mainly the old style fuse box.

I do NOT want to hear about regulations etc.

Our shower blew out the fuse a while back so we had to get someone in to re-do the wiring for it. He also checked the rest of the sockets.

Some of the sockets have resistance of around 1230 ohms coming down. If he reverses the wires then the resistance drops down to below the 50 ohm mark.

He has left us with a temporary circuit breaker for the shower and we are going to hunt down the resistance.

Just thought I would ask on here, what we are looking for (have an idea but looking for other opinions)

We are trying to avoid a re-wire due to the mess it would leave!

TIA

penrhyn

Resistance between where?

Enterprise_1701C

Between several different sockets and the wire in the fuse box.

Do not know where it starts or ends specifically.

Andy_WSM

Enterprise_1701C wrote: »

Between several different sockets and the wire in the fuse box.

Do not know where it starts or ends specifically.

Then it's clearly not safe to be working on your own electrics. Sorry, I know it's not what you want to hear, but that's why sparkles undergo training.

penrhyn

I agree with the above, You would not find Captain Kirk crawling around the Jeffries tubes looking for a high resistance joint exhibiting the characteristics of a dodgy cats whisker, he'd leave it with Scotty.

Enterprise_1701C

Andy_WSM wrote: »

Then it's clearly not safe to be working on your own electrics. Sorry, I know it's not what you want to hear, but that's why sparkles undergo training.

Not intending to "work" on them as such, just want to find out where it is coming from. If we disconnect the power and then disconnect the sockets then the resistance should drop down considerably should we find the right one as I understand it.

We do not touch things we don't understand, our sparky knows what we are capable of and he will finish the job if we can just trace the problem.

We have changed sockets in the past (incidentally, those sockets are perfectlly alright!!), just thinking that it might be a case of the sockets are on the old side too.

fwor

Enterprise_1701C wrote: »

Some of the sockets have resistance of around 1230 ohms coming down. If he reverses the wires then the resistance drops down to below the 50 ohm mark.

This doesn't make a lot of sense - if what you are saying is true then it doesn't ~look~ like a simple wiring fault. Which means that you probably aren't accurately recalling what he said.

Anyway, presumably this problem is just on one circuit? If so, all you can do is turn off the consumer unit main switch (do not just remove the fuse for that circuit, turn the whole lot off), find every socket and junction associated with that circuit, get to the back of each and check for signs of overheating. If the socket/junction box is not damaged, try tightening the connection and testing again. Replace any that have overheated to any significant extent.

Farway

Have you tried unplugging [not just switching off] the items on the ring main affected"

Are you able to measure the resistance yourself? I guess not from what you say, so how will you know when you have found the fault? Unless of course it is an obvious one as fwor says, overheating on the rear connections

Overheating is possible, try any sockets associated with large power use, like fires, tumble drier, cooker if the plug in sort

System

It sounds like there was something still plugged into a socket when the sparkie tested which is exhibiting the characteristics of a diode high R in one direction and low in the other.

Foxana

Hi, Enterprise 1701C.

If you have a tester (multimeter costs £5-10 from Amazon/maplin) and common sense (to stop health and safety supporters from moaning) then I don't see a reason why you can't find a fault and even fix it yourself.

Takes quite a while though without proper tools and you'll need to undo some/all sockets until you find an offender. Unfortunately, unplugging things may not be enough. Although I'd start from that.

Have you got a bit of knowledge about how your house is wired and general principles of how it should be wired? Are those "high readings" sockets on a main ring or radials? Is the wiring twin-and-earth or you still have steel conduits used as an earth conductor?

Post here or PM me if you need further info/instructions.

P.S. I am no electrician but me and my husband have studied well at school and we've recently DIY rewired the whole house. Property passed an NIC test without any faults/recommendations. Some might say that the tester can't check what's in the walls or under the floor so there is no guarantee. But hey, I've done it for myself, my kids and family... so no cutting corners and compromises. Google and youtube is a great source of info, btw.

Enterprise_1701C

The sockets are on the main ring main. We can measure the resistance ourselves, have got one of the plug top-type testers with the probe sockets, (already have a reasonable multimeter) we just have not had chance and now want to avoid turning off the power until we have got the new fridge as the old one takes forever to cool down at the moment!

The cooker is on a separate circuit, so is the immersion (which is not in use) - was rather hoping that would be the culprit!! Do not have tumble drier or electric fire, can't really think of anything high power using a socket, except maybe the freezer, not sure if even that would be high power enough!

The sockets are twin and earth, although the earth is unsheathed so we also need to sheath the earths.

There was nothing in the house plugged in, went around and checked absolutely everything. Rather hoping that the resistance will have just dropped by the time we get around to re-measuring it all. We are aware it is a long job but are perfectly capable of doing it ourselves then getting our sparky to finish off the job he started (was going to instal a new circuit breaker as the shower wrecked the fuse well and truly!!).

Thank you for the offer Foxana, will pm you if we need more assistance.

Asked the question because we thought it a bit strange too, but I watched him take the measurements so know it was right, but as it is just on the one circuit, We will go around disconnecting a few sockets (he left us with the "map" of the socket measurements) to see what state they are in and see how far we get.

We will obviously turn off the power.

I learned to respect electricity when I was little. My father served an apprenticeship with the Electrcity Board. He taught me how to put in a socket which I was 11, if I buy a new light I instal it. I just say this to make sure people know that I am not being silly and dealing with something I do not know about

!!!!!! - that is what we thought, but have been searching for an unseen socket with something plugged in - cannot find one anywhere, really think everything was unplugged.

Now, if it was gas, I would not go near it because we do not know how to deal with it.