5 Biggest DIY Mistakes Wiring a Socket

Sorry I'm twisting my earths together thank you very much as earth circuit continuity is paramount (I only twist the last half inch or so though not the whole length).

Also:
One has recently become aware, due to experience, of an inherent problem where metal boxes are fixed in place with screws that have countersunk screw heads.
The screw head can present a really sharp eadge, that, because the box holes aren't countersunk, remains very slightly proud of the metal surface.
Should a wire become hooked up on or resting against the eadge of the head, it can very quickly wear through the cable insulation. 👍.
Cheese head or rounded screw heads are my preference now.

Thanks, very useful. But I'd dispute that it's only DIYers who make mistakes and shortcuts. Frankly, I could have done a better job than a lot of the trades involved in my new-build house.

If you're worried about lining up screws you need to see a psychiatrist.

Grommets saved so many lives over the years.

There would be a national emergency if it wasn't for them !

I ALWAYS use a booted ferrule when terminating cables, I'll also use heat shrink. Not standard, but looks VERY tidy.

I've never heard of the screw thing, I call that ocd.

Another common mistake is not cutting back the insulation enough, when the terminal screw is tightened the screw clamps down on the insulation giving a poor connection

Not sure why aligning the socket-plate screw slots vertically is important... A tad OCD if you ask me...
Otherwise, all very good (though common sense) tips.

No grommets and I’ve seen a mouse nest in the box, fire risk all day long

I would suggest that taking a fly lead from the cpc terminal to the ko box is unnecessary. Were the box to somehow become live the plate screws would result in a very low impedance earth fault resulting in instantaneous disconnection. Even if this were not to happen ( an unlikely scenario) the heads of the 3.5 mm screws recessed into the plate would hardly present a shock risk.
The purpose of these lugs was when it was customary to run an earthed conduit to an accessory and not have a cpc cable, but usung the containment as the fault path. This is still permitted but seldom encountered. The lug provided means to bring the earth potential on the accessory's box onto the accessory be it a socket, switch, fused connection etc.via a fly lead into the earth terminal or lug.

British electrical standards are way behind European ones,
- metal boxes, why?
- one type of socket with phisical switches, what is the reason for them? Just unplug cable.
- shallow boxes, forget about any smart relay, switch, socket etc
- ground cable suddenly require brasilian t-shirt, why it is not manufactured dressed up?
- safety (ground) pin is not required for most low current devices
- square contact between plug pins and socket, why not round?
- massive 90 degree plugs in laptop bags can distroy laptop screen under preasure (weight) while traveling
- stupid adapters needed
- low selection on design (all houses looks like from communist county)
- mostly no N wire in light switches (finally standars has changed)

Fly leads to back of box are not required, as long as there is one fixed lug on the back box!

I have an autistic son and over the years have been exposed to autism and come to understand a lot about it. Lining up the screws in the sockets is 110% what my son would do. One good point is autism is not a mental illness. It is a developmental issue instead. Lining up screws is something you would absolutely want to avoid. Making an autistic son fit into a random world is all about having pictures at a slight angle, sockets not quite at the same height or level. Teaching how to accept things as they are and not to stress out over trivial things that do not matter will help everyone in the long run.

Great video. Funny I thought I was a rank amateur for bending back the ends of single core (professionals often don't seem to bother). P.S. Do a bit of voice coaching - at about 4min50sec you relax and the voice becomes natural and flowing. Many thanks again.

I actually worked for a guy who was a bit of a dick tbh and he refused to supply grommits he said that if the gray was actually inside the steel box he considered that as double insulated. Just to save the cost of a box of grommits. I didnt stay long.

what's the advantage of aligning your screw head direction on the socket?

Doubling over solid cores not recommend, fly earth not insulated, cable terminations not tested by pulling on them.

Another one is back boxes that are too shallow. Trying to fit a faceplate on when there are too many wires in the way. I'm restoring an old house at the moment. When it comes to first fix I plan to fit 32mm, or more, deep boxes in all the stud walls (they are thick enough).

I’m a DIYer and have followed up on a few professionals and found they have not tightened the contact screws properly with obvious results.

You did well until the final thing about screw directions. You do up screws to the correct tightness, and the slot then faces whatever way it faces.

Seeing screw notches aligned is a sign of a tradesman with an attention to detail. Telling DIYers to do it makes that sign meaningless.

Showing the correct sheathing technique at the end would be good.
Otherwise great video 👍

i fell asleep listening to his droney voice

Doubling the end of the wire over to get a better surface area ? Fine, works well when there is only one or two cables going in the contact - but if there are three then it gets difficult to get them all in.

Re the first one - grommets. I don't agree. When the cable is through the hole into a metal back box that will likely be surrounding by plaster. Once the cable is buried behind plasterboard or covered over with plaster, it ain't going to move at all. So no chance of the cable rubbing against the edge of the hole in the box. So why do they feel grommets are needed ?

I'm a sparky and the number of sparkies I know that are to lazy to put on grommets and who do not earth the back box or use an earth sleeve if they do never ceases to amaze me , furthermore I have seen many a sparky cut the cable so short that it's a real struggle to wire in the back of the socket at all . Truthfully this upload applies equally to DIYers and so called professional electricians who do not take pride in their work .

Mounting a socket on a backbox. C1. Tut tut. 😁

shocking

The other reason for a grommet is in some cases the cable will vibrate and wear the insulation from the cable eventually shorting out onto the metal box. I'm a retired sparky and when I first started as an apprentice I had a desk my dad built in my room, so I wired it up and I had a particular corner where it was difficult to get fixings. Everything appeared fine except when things got very quiet, I could hear a vibrating hum, it took me forever to trace it back to the corner, I eventually had to make a tight bend to get close fixings on the cable and stop it vibrating.
How long does it take two electricians to change a lightbulb?
How about 5 hours!
Why?
When you go to a building to fix a light fitting and you get there, to be escorted to a huge door. When they open it you find a huge freezer, and the light, a 5ft fluorescent encased in 300mm of ice.
The problem was they couldn't switch off the freezer unit, that was a matter of inches from the fitting, so, even with arctic jackets on it was our fingers and feet that got cold quickest. We had to use a hot air stripper to warm the fixings that were frozen solid once they started to move we took it away and the fixing instantly froze again. From that we estimated the temperature we were working in was -50°C! The estimate was taken from a survival book, if you are at either Pole and don't know the temperature, spit, if it hits the ground and freezes instantly it is -50, if you spit and it immediately freezes it is -70, so removing the heat gun it had to be at least -50 for it to freeze immediately.
Have you seen the new MK Smart sockets, £250 each, thank god I'm retired.

As an ex sparky I totally agree with all your comments apart from the final one. There is absolutely no electromechanical advantage/ reason for aligning the fixing plate screw heads . Yes you often find this detail on fine cabinet making and boat building but only for decorative or aesthetic purposes. I think you need to point that fact out in your video

You don’t have to earth the back box of it has at least one fixed metal lug

I was wondering what situation you would have 4 wires in a socket terminal . ? I can understand 1,2, and 3 wires but not 4 4?

I thought all earth conductors had to be multi stranded and insulated.

These are the 5 biggest mistakes you could think of? 3 of them are just your opinion, none are particularly dangerous, one is entirely aesthetics with no technical basis whatsoever.

Another big one that you see a lot is terminal screws tightening down onto insulation instead of copper.

You should see what the qualified spark did at my house. 🤦‍♂️

It’s why I completely rewired and fitted a new CU. All perfectly legal.

Or do what we do in Australia and use no box!

Fault one: over the time period you are talking about, the rubber grommet will have disintegrated anyway, much better to de-bur the metal.
Fault two: if you have too much cable you will struggle to seat the socket without cracking the case & folding the cables over on themselves causing stress to the copper.
Fault three: ironically you talk about causing stress to the copper but folding the wire over causes the same stress & you will still get impact damage from the screw. Also when the cable is doubled over you get mostly will get uneven clamping & the wire is much more likely to come loose over time.
Last fault: As for socket screws, how is that a fault?

Back boxes only need a cpc connection if both screw holes are adjustable. If one is fixed, no need.
AND
You can test 'one way' with twisted cpc if you take the live conductors out of their terminals (and at the MCB too).

Gromets are good. However, in 42 years in the trade I have never seen a single cable damaged by metal boxes. That's because the wires are plastered in and do not move. I have seen installation damage - and that's carelessness. However, to cut through all the sheathing to the point of contact is too rare for me to have ever encountered.

You missed the main mistake which was to do it them selves

I agree with everything you said and while it is a good idea to always run the cpc to a metallic backbox - as far as the regs are concerned it is only mandatory when the socket you are installing does NOT have an earthed screw hole at the FIXED backbox lug. Most brands of sockets these days strap both holes (or are fully metallic anyway) so it is usually unnecessary.

Think it illegal in Scottish law for someone with no electrical training to carry out installation of sockets. Only replacement

Although the video is good and the issues you raise are real, as a competent DIY'r I find this overly patronising and insulting to title it as DIY mistakes.
It has been shown time and time again that so called professional electricians make every single one of those issues you have said on a regular basis.

They are just mistakes made when wiring a socket, nothing to do with DIY.

Learn a trade before preaching a trade. Some of us have been doing this since before you were a sperm.

You're a bit of a jobsworth, hey, born in the nineties by any chance?

In my house, UK 1978, most of the screws holding the sockets and switches to the boxes have had their threads mangled. One handyman said this is caused by inappropriate use of power screwdrivers.