20A switch & 13A skt off ring

[John-SJW]

A final ring circuit. A 20A switch spur off the ring feeding a single 13A socket supplying a Modem in a large plastic Modem box. The spur is restricted to 13A and only one outlet, appearing to conform. Do regs say the fuse has to be at the tapping of the ring?

 

[loz2754]

No

 

[littlespark]

Think grid switches for kitchen appliances.
20A DP switch as spur point off the rfc.... each spur is unfused to one point. Be that a socket or whatever.

the spur only needs a fuse if it is then supplying more than one point.

 

[John-SJW]

Think grid switches for kitchen appliances.
20A DP switch as spur point off the rfc.... each spur is unfused to one point. Be that a socket or whatever.

the spur only needs a fuse if it is then supplying more than one point.

Yes, a fuse will be on the spur, being a 13A socket it has to be. Yes, gridswitching makes it clear the fuse can be downstream from the tapping on the ring, as long as the spur cable is protected. thx

 

[ipf]

You can spur once from RFC's at any point. Any outlet point, any cable (joint box) or at the circuit origin. Imagine FCU's at the side of sockets, under floorboards or inside consumer units, even, for every single spur point.

 

[John-SJW]

Appears people get confused at taking a spur from behind a socket. The terminals of a socket act as a junction box for the main current carrying spine of the ring. Theoretically, a socket is a spur off the main ring - look at the brass bits inside it to the three pin receivers, they spur off the terminals.

 

[ipf]

I’m not getting going again about busbars,? especially after the opening question.

 

[John-SJW]

The opening question was solved. As long as the spur is protected by a 13A fuse, at any point along it, then all is well. You can have as many switches on the spur as you like then.

Bus bars?

 

[ipf]

If more than one point, the spur has to be fused at its source, not any point along it.

 

[John-SJW]

The opening question was solved. As long as the spur is protected by a 13A fuse, at any point along it, then all is well. You can have as many switches on the spur as you like then.

If more than one point, the spur has to be fused at its source, not any point along it.

That conflicts with others here. Ref?

 

[ipf]

That conflicts with others here. Ref?

If you put individual FCU's for each point on an un fused spur, the additional points could lead to the load being too high for the spurred cable. With an existing spur, for example, all additional loads should be via one FCU.

 

[loz2754]

If you put individual FCU's for each point on an un fused spur, the additional points could lead to the load being too high for the spurred cable. With an existing spur, for example, all additional loads should be via one FCU.

I believe John said switches, not FCUs


Hang on a minute! I can't believe I'm defending the Wago busbar advocate! ?

 

[littlespark]

You wouldn’t have more than one FCU on on an unfused spur, as that would count as two points on the spur.

 

[ipf]

I believe John said switches, not FCUs

No difference, it's still load.

Bit of confusion spotted. It's the english. I've misconstrued 'at any point' as 'at any individual point', leading to thinking each fused unit being individual and local to the points.
Sorry.....but would maybe be better as 'the same 13A fuse at all points'.

The opening question was solved. As long as the spur is protected by a 13A fuse, at any point along it, then all is well. You can have as many switches on the spur as you like then.

Bus bars?

 

[loz2754]

No difference, it's still load

A switch is not a load. John, being John, is arguing that the line to the load can be switched by any number of switches. Not that there would be any point to that, of course.
I think that's what John, being John, is saying...?

 

[ipf]

A switch is not a load. John, being John, is arguing that the line to the load can be switched by any number of switches. Not that there would be any point to that, of course.
I think that's what John, being John, is saying...?

No, but it's purpose is to switch load. ?

I'm losing meself here. Look on U tube....someone'll prove something or other with a video.?

 

[John-SJW]

A switch is not a load. John, being John, is arguing that the line to the load can be switched by any number of switches. Not that there would be any point to that, of course.
I think that's what John, being John, is saying...?

The spur line to the load can have multiple switches, however you correctly gleened this would be pointless.

You are right in correcting others in that a switch is not a load.

 

[ipf]

The spur line to the load can have multiple switches, however you correctly gleened this would be pointless.

You are right in correcting others in that a switch is not a load.

'Others'?