Wagos on Final Ring Circuits

[pc1966]

That is my argument. Looking at the Wago, which has a mini bus bar inside, it is not an interpretation, it is multiple point connections from the ring, not a single point.

You are totally missing the whole point of why there are rules limiting spurs off a RFC.

Why is the RFC allowed to use 32A OCPD when the usual 2.5mm cable is 20-26A CCC limit?

Because of diversity in the type of loads and the assumption that the loading is distributed to a moderate degree over the length of the loop, so both 'legs' from the OCPD are sharing the current to a reasonable degree.

The same reason why the regs advise not to put large fixed loads on the RFC - it is not part of the overall strategy for allowing less copper to serve a much bigger area.

Running two spurs off a Wago joint (or any other joint) is NOT achieving that diversity of loading along the length of the ring. It is electrically indistinguishable from taking spurs off spurs as far as the load on either leg of the ring is concerned.

Your argument is like a lawyer looking for a loop-hole, not an engineer analysing the who and why that regulations have developed.

 

[John-SJW]

You are totally missing the whole point of why there are rules limiting spurs off a RFC.

Why is the RFC allowed to use 32A OCPD when the usual 2.5mm cable is 20-26A CCC limit?

Because of diversity in the type of loads and the assumption that the loading is distributed to a moderate degree over the length of the loop, so both 'legs' from the OCPD are sharing the current to a reasonable degree.

The same reason why the regs advise not to put large fixed loads on the RFC - it is not part of the overall strategy for allowing less copper to serve a much bigger area.

Running two spurs off a Wago joint (or any other joint) is NOT achieving that diversity of loading along the length of the ring. It is electrically indistinguishable from taking spurs off spurs as far as the load on either leg of the ring is concerned.

Your argument is like a lawyer looking for a loop-hole, not an engineer analysing the who and why that regulations have developed.

I know exactly what ring circuits are and how they work. You are mainly on about the design of the circuit, in not bunching heavy appliances on the ring. Good design would have a balanced ring - leg A to socket 1 (or FCU), then socket 3, 5, 7, etc, with leg B to socket 2, then socket 4, 6, 8, etc. So when adjacent w/machine and dryer are on, one is drawing off leg A and one leg B, balancing.

You are saying that having heavy appliances bunched off a ring, as in a kitchen is bad design. Of course it is, but legal. I have seen FCUs over worktops in twin boxes. That means the ring cable between the FCUs is inches long, then the sockets further along the worktop. When many appliances are on, w/machine, dryer, dishwasher, electric kettle, 3kW oven, toaster, etc, the ring is highly unbalanced - this is an issue. This setup is common. It is bad design. You are implying that in this situation it is no better than daisy chained spurs off a ring (daisy chained spurs are against regs). It isn't really, but your point is taken.

However, I have seen sockets all bunched off an upstairs ring, bedrooms converted to an office is common, but each one is drawing very low levels of current, via laptops, games consoles, printer, computers, etc. The ring is unbalanced, but the load is so low it is not an issue. On my ring I have a TV, computer, kitchen extract fan and a toaster. The ring is highly unbalanced when the toaster is on, but again the current draw is so low it is not an issue.

A 4 connector Wago with the ring in No.1 then out of No.4 (either ends of the Wago bus bar) with a spur off No. 2 and another off No. 3, is not daisy chaining spurs, as both are off the ring. If having spurs next to each other of course sensible design has to come in, in not having heavy current loads bunched, which of course a Wago can do. Having a Wago serving two spurs off an upstairs, lightly used, ring circuit would give no problems.

 

[DPG]

I give up.

 

[John-SJW]

?

 

[Lucien Nunes]

This is not the argument you were trying to advance earlier. You are now comparing the effects of bunched loads in different situations, and I am broadly in agreement with your analysis. Your original point, however, was that there was a fundamental difference in concept between the use of a Wago (with a specific in-line internal structure) and the use of another suitable connector of equal performance but different structure for the same purpose, namely connecting two spurs to a ring that may or may not represent a significant bunching of load.

Like DPG I am close to giving up but I would like to hear your opinion of the MK1132 junction box:

30A 3 Terminal Junction Box - White | MK (1132WHI)

 

[loz2754]

This has got to be a windup!
A Wago is a connector, not a busbar.
OP is almost religiously dogmatic in stating that the Wago is indeed a mini busbar. A totally ridiculous and unsupportable argument IMHO.

 

[John-SJW]

My original point was that a Wago has a bus bar inside. This bus bar is a part of the ring when the ring cables are connect at each end. Then a number of spurs can be taken off the bus bar - is not daisy chaining spurs, as some thing it is.

The j box below would do exactly the same if wired the same way as the Wago, as can be seen a bus bar is there.



The above j box is quite different to the normal one like below, where thers is no bus and all cables are into one terminal:

 

[John-SJW]

This has got to be a windup!
A Wago is a connector, not a busbar.
OP is almost religiously dogmatic in stating that the Wago is indeed a mini busbar. A totally ridiculous and unsupportable argument IMHO.

Look at one. Do not take my word for it.

 

[John-SJW]

This is not the argument you were trying to advance earlier. You are now comparing the effects of bunched loads in different situations, and I am broadly in agreement with your analysis.

I was responding to a poster.

I have not read of any limits of sizes of bus bars - can be 1/2" or 2 foot.

 

[MrMan1O1]

I know exactly what ring circuits are and how they work. You are mainly on about the design of the circuit, in not bunching heavy appliances on the ring. Good design would have a balanced ring - leg A to socket 1 (or FCU), then socket 3, 5, 7, etc, with leg B to socket 2, then socket 4, 6, 8, etc. So when adjacent w/machine and dryer are on, one is drawing off leg A and one leg B, balancing.

You are saying that having heavy appliances bunched off a ring, as in a kitchen is bad design. Of course it is, but legal. I have seen FCUs over worktops in twin boxes. That means the ring cable between the FCUs is inches long, then the sockets further along the worktop. When many appliances are on, w/machine, dryer, dishwasher, electric kettle, 3kW oven, toaster, etc, the ring is highly unbalanced - this is an issue. This setup is common. It is bad design. You are implying that in this situation it is no better than daisy chained spurs off a ring (daisy chained spurs are against regs). It isn't really, but your point is taken.

However, I have seen sockets all bunched off an upstairs ring, bedrooms converted to an office is common, but each one is drawing very low levels of current, via laptops, games consoles, printer, computers, etc. The ring is unbalanced, but the load is so low it is not an issue. On my ring I have a TV, computer, kitchen extract fan and a toaster. The ring is highly unbalanced when the toaster is on, but again the current draw is so low it is not an issue.

A 4 connector Wago with the ring in No.1 then out of No.4 (either ends of the Wago bus bar) with a spur off No. 2 and another off No. 3, is not daisy chaining spurs, as both are off the ring. If having spurs next to each other of course sensible design has to come in, in not having heavy current loads bunched, which of course a Wago can do. Having a Wago serving two spurs off an upstairs, lightly used, ring circuit would give no problems.

You mentioned in another post that wagos can be a get of jail free card, but if you're taking two spurs off one WAGO terminal then it's you that could be going straight to jail I'm afraid.
A WAGO is not a ring conductor, It's a terminal for goodness sake.
As for balancing loads on a ring circuit....er, hello, it's a ring....the two cables coming from the CU actually act as one, and each cable will carry half the current of the total load from all the outlets.....of course the load varies along the length of the cable but all that means is the point of "balance" (searching for a better word) of current flow will change accordingly.

 

[Lucien Nunes]

the two cables coming from the CU actually act as one, and each cable will carry half the current of the total load from all the outlets

I don't think this is quite what you meant to say. Either that, or you will have to haggle with Mr Ohm and get him to change his ideas about proportionality between V and I in metallic conductors.

 

[Pete999]

I give up.

Me an all

 

[Pete999]

My original point was that a Wago has a bus bar inside. This bus bar is a part of the ring when the ring cables are connect at each end. Then a number of spurs can be taken off the bus bar - is not daisy chaining spurs, as some thing it is.

The j box below would do exactly the same if wired the same way as the Wago, as can be seen a bus bar is there.

View attachment 63817

The above j box is quite different to the normal one like below, where thers is no bus and all cables are into one terminal:

View attachment 63818

But aint MF

 

[Lucien Nunes]

The above j box is quite different to the normal one like below, where thers is no bus and all cables are into one terminal:

Quite different indeed. In one, the cables are clamped by screw pressure against a piece of brass of negligible resistance, whereas in the other, they are clamped by screw pressure against a piece of brass of negligible resistance.

Having finished work now, I'm off home. Kat is still away visiting her family so I am going to have a mixed grill. I'll fry a couple of Wagos in case I need to spur off the onion rings, although there isn't mushroom in the back box.

TTFN

 

[John-SJW]

You mentioned in another post that wagos can be a get of jail free card, but if you're taking two spurs off one WAGO terminal then it's you that could be going straight to jail I'm afraid.
A WAGO is not a ring conductor, It's a terminal for goodness sake.
As for balancing loads on a ring circuit....er, hello, it's a ring....the two cables coming from the CU actually act as one, and each cable will carry half the current of the total load from all the outlets.....of course the load varies along the length of the cable but all that means is the point of "balance" (searching for a better word) of current flow will change accordingly.

That is totally incorrect. Here is a vid on the inbalance between the legs of a ring circuit:

"A WAGO is not a ring conductor, It's a terminal for goodness sake."

Mmmm No. Manufacturers at times design products that are used for different purposes for what they were intended. An e.g. is the transistor. Bell Labs designed it to make long distance telephone calls clearer. It was used by others to replace valves in radios - to Bell's surprise.