2 ms·

Earths are to be connected to a single point, not multiple terminals of a Wago block or similar, in the UK at least. Twisting is not afaik a requirement, but it

by OJFord 3y ago

Earths are to be connected to a single point, not multiple terminals of a Wago block or similar, in the UK at least. Twisting is not afaik a requirement, but it's common, and adds to the security of it. (At least, as long as the solid core hasn't been twisted and untwisted repeatedly and near the point of breaking.) OP appears to be doing it to make a fatter gauge cable out of smaller ones though?

BrandoElFollito 3y ago
You mean that the earth cable should run uninterrupted as a single wire from the connector of the device to the power cabinet?
- OJFord 3y ago
  Take a ceiling rose light fitting for example; you have: - twin core & Earth line - twin core & Earth to next fitting (or back to cabinet to complete the ring) - live to switch & switched live return - flex live & neutral (+ Earth if not double insulated) to light fitting those 2-3 Earths obviously need to be electrically connected, and that is not supposed to be done with a multipoint terminal block. They are supposed to be under a single screw in the light fitting say, or twisted together & sleeved. I believe it's thought that it reduces the chance of failure - one connection to check vs. a terminal block of three 'connections' where it's easy with solid core to think that they're secure when actually the middle one isn't, it's just roughly prevented from slipping out by the stiffness of the others, and potentially isn't a good electrical connection.
  - Maxion 3y ago
    The UK electric code is wild. A ceiling rose light fixture in Finland has three wires: - Earth - Neutral - Live
    - OJFord 3y ago
      It can be like that, it's not a requirement, but once you know what's going on it's actually quite convenient to have the chaining. Not if you're trying to stuff it all in a small fitting that wasn't designed for it, but otherwise. I suspect Finnish spotlights are similar - they run in a chain not all individually to the switch? So only the last one has just the feed and nowhere to go? Difference is in the UK we have 'ring' circuits, where the 'end' as it were goes back to the consumer unit (power cabinet). It's mostly a post-war hangover: if the load is assumed fairly even then it means you can use half the wire diameter vs. not having the return, which was thought with typical and logical layout would mean less cable overall, since the 'end' would already be back around the other side close to the CU again. It has some safety advantage too, but AIUI it's slowly fading out of vogue for new installations and it will likely end eventually. (Some critique it that with modern patchy load distribution it actually now ironically requires more copper than the equivalent radial circuit, and probably not post-war level but copper's expensive again.)
zokier 3y ago
> Twisting is not afaik a requirement, but it's common, and adds to the security of it. Not clear what sort of connection you are referring to here? And how twisting improves it? But I'd be surprised if there wasn't better option available
- mauvehaus 3y ago
  Wire nuts, likely. The directions on the last box I bought say that twisting is allowed but not required. I would think the reason to twist is to improve the mechanical connection, not the electrical one. It should make it more resilient to grabbing two wires and pulling in opposite directions. Which shouldn't happen in practice anyway, but, you know. Regardless of how you feel about wire nuts, if you're in the US, your house is probably full of them.
  - OJFord 3y ago
    No, I've never seen them (not that I'm an electrician, but nor for sale) in the UK.
- OJFord 3y ago
  To a single point as I said, I'm not really sure how else to describe. Could be ring terminals crimped on and under a single screw, that would be better. But twisted cores under screw beats not twisted under screw - even just twisted and no screw (as is common especially in say light fittings that are double insulated/no metal to begin with, no Earth point) is probably better.
  - zokier 3y ago
    So screw/stud termination. Yes, ring or spade(/fork) lug would be much better than bare wires, twisted or not. As I understand it, crimping is almost always the preferred way to terminate/connect wires.
    - OJFord 3y ago
      Yep, there's often not a lug though, and they'll either be twisted and flapping about, or in the (same side of, if applicable) a single terminal; in the latter case I would think twisting is better than not, or better than separate straight crimps. Certainly not worse. It was just an example of when it's done, I was never trying to say it's the absolute best, no other way.
flipbrad 3y ago
My electrician (UK) was recently very upset at use of twisting in sockets - made uncoupling them (to bisect the ring and thereby find where a fault was occurring) very time consuming.

by OJFord 3y ago

BrandoElFollito 3y ago

You mean that the earth cable should run uninterrupted as a single wire from the connector of the device to the power cabinet?

OJFord 3y ago
Take a ceiling rose light fitting for example; you have: - twin core & Earth line - twin core & Earth to next fitting (or back to cabinet to complete the ring) - live to switch & switched live return - flex live & neutral (+ Earth if not double insulated) to light fitting those 2-3 Earths obviously need to be electrically connected, and that is not supposed to be done with a multipoint terminal block. They are supposed to be under a single screw in the light fitting say, or twisted together & sleeved. I believe it's thought that it reduces the chance of failure - one connection to check vs. a terminal block of three 'connections' where it's easy with solid core to think that they're secure when actually the middle one isn't, it's just roughly prevented from slipping out by the stiffness of the others, and potentially isn't a good electrical connection.
- Maxion 3y ago
  The UK electric code is wild. A ceiling rose light fixture in Finland has three wires: - Earth - Neutral - Live
  - OJFord 3y ago
    It can be like that, it's not a requirement, but once you know what's going on it's actually quite convenient to have the chaining. Not if you're trying to stuff it all in a small fitting that wasn't designed for it, but otherwise. I suspect Finnish spotlights are similar - they run in a chain not all individually to the switch? So only the last one has just the feed and nowhere to go? Difference is in the UK we have 'ring' circuits, where the 'end' as it were goes back to the consumer unit (power cabinet). It's mostly a post-war hangover: if the load is assumed fairly even then it means you can use half the wire diameter vs. not having the return, which was thought with typical and logical layout would mean less cable overall, since the 'end' would already be back around the other side close to the CU again. It has some safety advantage too, but AIUI it's slowly fading out of vogue for new installations and it will likely end eventually. (Some critique it that with modern patchy load distribution it actually now ironically requires more copper than the equivalent radial circuit, and probably not post-war level but copper's expensive again.)

zokier 3y ago

> Twisting is not afaik a requirement, but it's common, and adds to the security of it. Not clear what sort of connection you are referring to here? And how twisting improves it? But I'd be surprised if there wasn't better option available

mauvehaus 3y ago
Wire nuts, likely. The directions on the last box I bought say that twisting is allowed but not required. I would think the reason to twist is to improve the mechanical connection, not the electrical one. It should make it more resilient to grabbing two wires and pulling in opposite directions. Which shouldn't happen in practice anyway, but, you know. Regardless of how you feel about wire nuts, if you're in the US, your house is probably full of them.
- OJFord 3y ago
  No, I've never seen them (not that I'm an electrician, but nor for sale) in the UK.
OJFord 3y ago
To a single point as I said, I'm not really sure how else to describe. Could be ring terminals crimped on and under a single screw, that would be better. But twisted cores under screw beats not twisted under screw - even just twisted and no screw (as is common especially in say light fittings that are double insulated/no metal to begin with, no Earth point) is probably better.
- zokier 3y ago
  So screw/stud termination. Yes, ring or spade(/fork) lug would be much better than bare wires, twisted or not. As I understand it, crimping is almost always the preferred way to terminate/connect wires.
  - OJFord 3y ago
    Yep, there's often not a lug though, and they'll either be twisted and flapping about, or in the (same side of, if applicable) a single terminal; in the latter case I would think twisting is better than not, or better than separate straight crimps. Certainly not worse. It was just an example of when it's done, I was never trying to say it's the absolute best, no other way.

flipbrad 3y ago

My electrician (UK) was recently very upset at use of twisting in sockets - made uncoupling them (to bisect the ring and thereby find where a fault was occurring) very time consuming.