Domestics again

JohnW2 said:

I have a reasonable degree of knowledge, 'skill' and,dare I say, 'competence' across what is probably a fairly unusually wide range of disciplines. However, I have only been formally 'trained, qualified and experienced' in a relatively small proportion of those disciplines, many of them having been 'self taught', usually by reading and doing things like 'looking at diagrams' (or, theses days, I suppose also videos!).

Conversely, I'm sure we've all seen examples of people who have been formally trained and qualified, with lots of 'experience' (often experience of doing this badly or incorrectly!) who are not really 'competent', or necessarily even safe, in what they do!

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Dragging that from another thread flowed nicely into my today little just job and the reason my post on '6 core flex' was delayed by several hours:

I was out on a light switch replacement this afternoon.
One which was replaced yesterday (Sunday) by an insurance service. We were sent in today by the insurance company to sort it out as it was reported as 'keeps tripping the fuse'.

The broken switch was in the rubbish bin, 4 gang 2 way with 'Loop terminals - very handy to have the instant comparison/explanation with the replacement! the faceplate is basically broken in 2 with a chunk of it between 2 switches missing and bits of exposed brass.

Replacement switch 4 gang modular (I assume from SF as very close by) fitted with intermediates

Also in the bin was last years TV license with this on the back... even handier!!
I assume it shows the 'before connexions' and the replacement had been wired exactly the same although the ladies told me he spent ages trying different combinations.
I've marked the terminals with a blue circle which had been 'LOOP' terminals but now the intermediate switch L1' lines
I've marked the terminals with a black square which were permanent neutral
I've marked the terminals with a red square which are permanent line

Switches 4 & 1 running on one lighting circuit but short L to N when switched off there seems to be 2 'loop ins' and 1 'loop out' the neutrals are linked (and have to be for the remainder of the circuit) but the lines are not linked

Switches 3 & 2 are on second lighting circuit
Switch 3 is switching neutral (cable #10 is feed to SW3 L2 and SW2 L2' [used as COM]) - Cable #6 T&E to the light has red, blue and green/yellow insulated cores and yes it really does appear to have those colours.
Switch 2 the SL (returned from distant switch via strapper) is in the switch's 4th terminal but doesn't affect operation

It didn't take long to diagnose why SW 1&4 tripped the RCBO and that was even without tripping it myself, it might have even taken longer to drink the COT than fix the errors. Apparently the insurance guy was there for several hours.

So what you're saying is there's a load of blacks that were neutrals that should have been terminated together, but were attached to various switch terminals?

And were the neutrals from different circuits?

securespark said:

So what you're saying is there's a load of blacks that were neutrals that should have been terminated together, but were attached to various switch terminals?

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They were originally terminated in 'LOOP' terminals on 2 way switches then on line terminals of new intermediates.
Switching either of the two outer switches off shorted L to N - not sure what's going on with the loop in and outs as 2 of 3 lines are live but 1 of 3 neutrals are live

securespark said:

And were the neutrals from different circuits?

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There are 2 different circuits there but no they aren't mixed

You still need the patience of a saint and the deductive reasoning of Sherlock and Poroit combined to work that lot out!

Mind you, as you say, it's better than sifting through a box-full of misplaced conductors without any clues whatsoever!

This reminds me of a call out I did to a suspiciously new looking metal plate switch in a kitchen. 3 gang, it was. The notes on the computer said, "switch was working up until last week"...

When I arrived, I flicked them all one by one. One light came on in series with another and another went off when another switch was flipped. It was a right mess. Almost every conductor was in the wrong place.

It was blindingly obvious that the customer had swapped the switch out themselves and made a right royal pig's ear of it. The report from the office was right...
The switch was working up until last week...but the customer declined to add the pertinent bit...when I swapped the switch for a new one!

It took me a while, but I got there in the end.

I have a 4 gang plate, god help anyone, but me working on it, two lights were from the flat supply, and one main house downstairs, and one main house upstairs, the latter is now extra low voltage as it works a relay.

It is about the only switch in the house which has neutrals at the switch, and it seems likely the neutrals had been mixed up since the house was built, and only when an all RCBO consumer unit fitted was the borrowed neutral found.

I do look at @JohnW2 "many of them having been 'self-taught', usually" and I do wonder what is not self-taught? Be it a book, internet, Clive, or a lecture standing in front of us, it is down to us to simulate that information. As school, we had teachers, who went around the class giving one to one, and even in collage and university there was some teaching, where someone would say you have got that wrong, this is why.

And in the days of using Clive (wonder if it still exists) with packet radio, I could ask others for help, but a lot of learning was as a result of necessity. We were having a new machine fitted with a PLC and the guy doing it had a heart attack, did not die, but I was left the finish it, it was a steep learning curve.

In Algeria, found I was the only engineering craftsman on site, did not matter what went wrong, I had to fix it, no one else could.

To a lesser extent same on the Falklands, I had never worked on a photostat machine before, lucky very good instructions, and it mainly did a self diagnostic, move wire A from X to Y if this happens it's OK and if this happens this is the problem, it was really down to reading a book.

I remember working on a concrete mixer/batching plant, rang up the manufacturer for help, told we will send out our guy, but when they realised it would take him at least a month, they faxed the instructions. And so easy.

But in industry the plans would tell me which tray the cable was on, and what each number or colour did, I have spent ages printing out shrink sleeve with the cables' designation, even motor vehicles 31 was earth for example, British White unfused, Purple fused, green ignition circuit fused etc. But when I came to work on domestic, I could not believe the knit one pearl one way of running wires. Red to red, yellow to yellow, and blue to bits.

What were three-phase colours doing in a single phase supply?