Tell us about your faults!

[44ALLAN]

nope ...still lost :-9

ok mate no interest elsewhere so here goes........one for your fault archives.

The new 3 phase/N feed into my office block was taken from a joint in the street outside which also feeds street lighting/pump house down the road etc etc.

Turns out the cable/joint/termination ( downstream from us) developed an earth fault on L3/blue phase/grey phase whatever you want to call it.

This earth fault blew the main fuse in their substation but the heat from the blast ( at the location of the fault) 'welded' L2 and L3 together at the same time clearing the earth fault..........if you get my drift ! lol

This meant L1 was still ok and fused.
L2 was still ok and fused.
L3 was now fused to L2 and being fed through L2 back to my main D/B giving me good tests on all single phases.

Moral of the story........if their is one lol
You can have good tests but still be in a fault situation.

Subsidence seemingly causes this problem on underground cables sometimes but not sure how often..........new one on me that's for sure.

Clear as mud mate

 

[Megavolt]

ok mate no interest elsewhere so here goes........one for your fault archives.

The new 3 phase/N feed into my office block was taken from a joint in the street outside which also feeds street lighting/pump house down the road etc etc.

Turns out the cable/joint/termination ( downstream from us) developed an earth fault on L3/blue phase/grey phase whatever you want to call it.

This earth fault blew the main fuse in their substation but the heat from the blast ( at the location of the fault) 'welded' L2 and L3 together at the same time clearing the earth fault..........if you get my drift ! lol

This meant L1 was still ok and fused.
L2 was still ok and fused.
L3 was now fused to L2 and being fed through L2 back to my main D/B giving me good tests on all single phases.

Moral of the story........if their is one lol
You can have good tests but still be in a fault situation.

Subsidence seemingly causes this problem on underground cables sometimes but not sure how often..........new one on me that's for sure.

Clear as mud mate

To be fair that is what I was trying to say that is way you showed 0 volts as they was same phase

 

[Bobster]

Old cable joints cause similar faults, quite common once they are in 30+years.

 

[44ALLAN]

To be fair that is what I was trying to say that is way you showed 0 volts as they was same phase

Originally Posted by Elrick
Are L2 and L3 the same phase



Meaning?
How could this be?



You certainly did mate I was just asking if you knew what fault could have caused it though and the clue was that non of 'my' breakers had tripped.

 

[44ALLAN]

Old cable joints cause similar faults, quite common once they are in 30+years.

Hi Rob,
I've seen a few 'strange' faults in my time and for a few moments this one had me bamboozled to say the least.
Then training kicked in...........think easy/think logically.
So I walked down to the main incomer and my new dazzling meter showed L3 was lost lol. (on the incoming side I hasten to add).
Fault finding at it's best.... quick phone call and someone elses problem

 

[electric will]

Short between L2 and L3 but only took one of the phases out?

a bit like what I said here then?

 

[Megavolt]

To be fair that is what I was trying to say that is way you showed 0 volts as they was same phase

Originally Posted by Elrick
Are L2 and L3 the same phase



Meaning?
How could this be?



You certainly did mate I was just asking if you knew what fault could have caused it though and the clue was that non of 'my' breakers had tripped.

I wouldn't of guessed what it was never came across this one before thanks for sharing got my grey matter going. What tester did you use to confirm it.

Thanks

 

[44ALLAN]

I wouldn't of guessed what it was never came across this one before thanks for sharing got my grey matter going. What tester did you use to confirm it.

Hi mate.
It might help a few to 'show-off' with their fault finding skills if they come across it in the future lol
It was a bit tongue in cheek about mine because our 3 phase meter has 'phase indication' on it and it showed L3 was missing
Confirmed it with my Fluke 1653 on the main incomer.
Local DNO guy was blowing 500amp fuses trying to clear the fault ffs !!!

 

[Stroppy]

Here's a good one: two two-core SWA's of differing csa's and a length of flex feeding some outside lights, connected with connector blocks, and made 'safe' (ish) by covering with silicone sealant, and buried between zero and three inches across a gravel drive! The doubled-back earth wire of the flex is taped to the swa plastic sheath, but the swa's armours are touching, so sort of achieving earth continuity.

Oh yes, protected by a 50A MCB. And as far as I can find (so far) no earthing to the installation whatsoever - definitely not PME in the 1930's cast iron head, and no conductor in the board that could end in an earth stake, unless the stake is connected to one of the final circuits somewhere.

 

[Stroppy]

Same house as above: noticed that every time you shut the front door the lights flicker. Found why, they are using these p1ssy little electronic 5 amp fuses in both lighting circuits which are considerably smaller than their correct BS1361 equivalents.

 

[£££sjim]

my biggest fault so far is using the ultimatehandyman electtrician site, some real unqualified nutters on there, check em out !

 

[Stroppy]

Non-shower-rated open mains voltage GU10 downlighter, dripping wet above a shower. Niiiice.

...and some mould, but I don't care about that!

 

[GT1]

New twin RCD board install, replacing wylex rewireable one.
Energised the board.. trip.
Id tested the whole house prior to the job with not too many faults...
However, it'd had lots of work done to it over the last 20 years.
The main culprit was one of the RFCs. However, there were other circuits which seemed to add to the problem.
Took the RFC in question, split into 2 radials to narrow the fault. Identified the half causing the problem and split that down even more.
Eventually found this in a socket, spurred off the ring. The little nick in the wire was just touching the earth terminal of the socket. Snipped it out and re terminated.. hey presto everything fine..
The annoying thing is it didnt show out on IR test, even when testing just that spur from the other side.
The only explanation I can give is that it must have been a fraction away from the contact, but when energised it was close enough to jump the gap..!!
3 hours of hunting... but got there in the end.

 

[Kamikaze]

Today’s little adventure!

If you have ever wondered how many wires you can squeeze down a 20mm coupling and into a surface mounted double socket box then wonder no more. It’s 12x 2.5mm singles and 1x 2.5mm twin and earth cable. If I had not seen it for myself I wouldn’t have believed it.

Needless to say it’s no longer like that now!

 

[dan86]

Got a pic Kam? sounds like a right squeeze!

 

[Stroppy]

Ttiwwop!!

 

[Kamikaze]

Got a pic Kam? sounds like a right squeeze!

Someone took a ring of the ring to another nearby socket and then for good measure added a feed for an extractor fan as well. Unfortunately forgot to take a picture but it took me ages to strip it out. The T&E had a twist in it as it came through the bush. But that is the most 2.5’s I have seen down a 20mm hole. Once saw 23x 1.5mm singles down a 25mm galv. conduit with two 90* bends. But that was a long time ago and it’s still there and working.

 

[drewman]

Customer asked me to look at why a downlight wasn't working. Removed it to change transformer and was astounded to find a 13a plug-in transformer pack into a socket (with no backbox) terminated on the end of the lighting circuit in the ceiling!

Amazed.

 

[GT1]

Nice neat hole too...!!

 

[sajeel]

called to a job where socket in kitchen was not working, i asked client if he has juction box underneath and he said no, i told him there must be junction box under there, anyway long story short, found a junction box with wire bitten by a rat or mouse who probably died, rotted and decomposed.