Ah - if only ignorance were bliss, eh?

[John D v2.0]

You taken some test kit on holiday????

Well I heard the iPhone 9 will have a built in mft app

 

[ericmark]

I have a friend who wanted me to look at a log cabin, the consumer unit was under a slate slab, together with the meter, I could see it, but as far as working on it clearly the slate slab when in after it was fitted, all the cables went in the same direction towards an area where I could easy access, so I fitted a new consumer unit and took every cable into the main switch and then from there to all the bits in the cabin, so original distribution unit was still in place, but did not do anything, the original ELCB-v also still in place, but again does not do anything other than be an isolator. New earth rod fitted, all tested OK.

Now anyone poking around could find the old fuse box and old ELCB-v but just around the corner was a new consumer unit with two RCD's. The next job was second log cabin where the ELI had come back as around 300Ω but after doing the first one, found the second one then showed around 30Ω second must have got it's earth from first.

Now if I consider that job, then yes a visitor could come away with tails of woe, anyone using a loop impedance tester and a RCD tester would realise it was all protected, but without test equipment it would be easy to miss the second brand new CU with new RCD's. The work was done after testing the second log cabin and finding the RCD would not trip using a RCD tester, however it would trip by pressing the test button on the RCD, then did a loop impedance test with really high results, I had voiced the dangers and it was then I was shown the cabin hidden in the woodland used only for visitors.

I would have thought the meter reader would have complained, to read the meter one needed to lie on the floor and shine a torch under the slate slab, some day some one will be asked to fit a smart meter I would guess, but there is no telephone line fitted, and no cell phone coverage so not sure how it would work? And in a SSSI site so can't cut trees down to lay cables, I want to be a fly on the wall when the guy comes to fit it.

 

[SUNRAY]

Years ago (late 80's) i rented a 'cabin' on a camp site in Exmouth for 2 weeks.
All electric on a slot meter, first 50p went in to for lights in bedroom, less that half hour it ran out, next 50p lasted a little longer as the immersion stat was kicking in.
Another 50p to male a cuppa and cer indoors nearly ended-up outdoors with the belt from the kettle/tap combination. My first port of call was the multimeter from the car tool kit and found lots of volts (> 240) between neutral and the water pipes and approaching 400 phase to pipes.
Their odd job guy tried to put a bond between pipeand earth/neutral bar and blew a hole in the copper pipe.
Turned out the row of cabins hadn't been used since some ground works and there was a contact between a damaged cable and the copper pipes buried in the ground, so the whole row of a dozen or so cabins had live water pipes.
We were moved to a different cabin where the leccy costs were far more reasonable.
I'd forgotten about it until this thread.

 

[ericmark]

I remember on the Falklands where I was employed mainly as an auto electrician talking with the boss, the generators were producing around 350 kVA but going around where they supplied he could only account for around 160 kVA could not be 100% as it took time to move around the site so load could fluctuate, but not that much.

So we talked about the where the power could be going, I told the story of how in the early days we had run out of cable joints, and while we waited we used Denso tape, making notes of where used, and once the joints arrived the repairs were re-done. There was a slim chance one of these had been missed, but where, and how to find.

That night we had light snow, and there was a dry patch of ground, that was luck, and yes there was a Denso tape joint, not bad, buried for 3 years and still working although leaking a lot of power, it would not have caused a problem had things gone to plan, that part of the complex should have been decommissioned by then, this is the problem with all temporary installations, they were to be temporary when done, but events change things.

 

[SUNRAY]

I remember Dad wrapping a junctionbox in the shed feed in denso tape when I was a nipper, it was one of those things that repeatedly crossed my mind as years progressed and after my parents death we rented the house out, each time the tenants changed it went forgotten until we did a significant refurb. The source was a ring final and the 3/0.029 twin spur clipped along the outside wall for 3m or so then o/h span 2m, JB wrapped in Denso and held on catenary with more Denso then 1/0.044 twin clipped 2m along shed then inside into a 2 pole ceramic fuse carrier. I recall Dad using a 2.5KW fan heater and power tools out there.
When I ripped it out the inside of the JB was as good as the day it was installed, even the protected part of the rubber cable was still supple after 30years.

 

[ban-all-sheds]

You taken some test kit on holiday????

Errr... no.

 

[securespark]

You taken some test kit on holiday????

Err... no.

So why write this

I think that fault loop readings might also be a bit dodgy.

when you have already said the following which, without any qualification, implies poor or non-existent EFLI?

No earth of any sort - not even incidental via main bonding because there is none of that either.

 

[Mottie]

Let me start by saying I have only the most basic understanding of electrics but the worse bit of electrics I have ever seen was in the early seventies when we moved into a new council house. I was 14 at the time. For the first time ever, we had a garden so my Dad bought an electric lawn mower to cut the grass. Unfortunately it was a home-made one that consisted of a standard push along lawnmower that had had an electric motor bolted onto it and the motor was connected to the rotating blade by the fitting of a couple of car dynamo pulleys and a car fan belt. This was powered by a piece of cable going from the motor to a single surface mounted socket, again, bolted to the handle. No on/off or speed control switch. The main problem was the main power lead had a three pin 13a plug at either end! I only clocked this as Dad was setting up for his first cut and had plugged one end into the kitchen socket. I shouted out a warning to my dad who said something along the lines of "Don't be ****ing sill............" just as he was thrown across the lawn! Worse thing was, he still kept the mower but always plugged the mower end of the cable in first!

 

[EFLImpudence]

In the trade, such an arrangement is called a widowmaker.

 

[ban-all-sheds]

So why write this

when you have already said the following which, without any qualification, implies poor or non-existent EFLI?

I was replying to this.:

Shockingly there are still some sparkies that do not know the difference between a voltage operated trip and an RCD, and will assume this install is fine. Obviously would/should fail a trip test.

I was pointing out that, wrt what sorts of things would be flagged up by testing, as well as the trip test failing, the fault loop readings wouldn't be healthy.

 

[ban-all-sheds]

Q to all.

What does the test button on a VOELCB do?

 

[flameport]

What does the test button on a VOELCB do?

It's a changeover switch on one side of the trip coil.
When not pressed - connects the coil to the installation, usually the earth terminal in the fusebox.
When pressed - connects the coil to line via a resistor, which should cause it to trip.
The other side of the coil is connected to the earth electrode.

https://www.flameport.com/electric_museum/old_elcb/index.cs4

 

[ban-all-sheds]

Ah - OK - so it's picking up an earth from somewhere.

Wish I'd tried unplugging the boiler before pressing the yellow button...

 

[securespark]

Did you reset it, unplug the boiler and press it again?

 

[ban-all-sheds]

No - the idea that I should have tried it without the boiler plugged in didn't occur to me until after we had left.