the wiring in my kitchen....

[ChrisRogers]

in my kitchen i have 4 mk gridmodules controling 4 single unswitched sockets for things like washing machines ect, these modules are rated at 20amps and are wired directly into the ring main. can i have your opinions on this? have just moved into a new house and am begining to rage war with the sparks.

 

[supersparks]

are you sure they are on ring and not radial? are they fused? is there one socket per switch? if there is one switch to a socket it wouldent make a difference because maximum load would be 13amps, but still not the best of practices

AR

 

[ChrisRogers]

they are on the ring, and are not fused before the switch, the only fuse for connected appliances is the one in the plug...

 

[supersparks]

and there is one switch per single socket?

 

[ChrisRogers]

yes, one switch per single socket,

i guess it is acceptable, I'm just not very happy with it

 

[ban-all-sheds]

It sounds like a neat solution to the requirement to provide a means of isolation for the appliances - why don't you like it?

My only concern is that you say there are no fuses, and I guess what you've got there are 4 spurs, with 20A isolation switches. Do you know what size cable has been used between the switch modules and the sockets?

If it's a single run of 2.5mm, then I think this would contravene the wiring regs, and therefore if it's a new house, be illegal. Which means you should be able to make them fix it (e.g. by replacing your 4 module gridplate with an 8-way, 4 switches and 4 fuses) FOC.

Did the house come with an electrical installation certificate?

 

[supersparks]

Sheds, one spur per switch, how does that break regs?

 

[ChrisRogers]

It sounds like a neat solution to the requirement to provide a means of isolation for the appliances - why don't you like it?

My only concern is that you say there are no fuses, and I guess what you've got there are 4 spurs, with 20A isolation switches. Do you know what size cable has been used between the switch modules and the sockets?

If it's a single run of 2.5mm, then I think this would contravene the wiring regs, and therefore if it's a new house, be illegal. Which means you should be able to make them fix it (e.g. by replacing your 4 module gridplate with an 8-way, 4 switches and 4 fuses) FOC.

Did the house come with an electrical installation certificate?

its 2.5 between the switches and sockets, and my concern is there are no fuses, can i ask what part of the regs its breaking?

 

[ban-all-sheds]

Sheds, one spur per switch, how does that break regs?

It's not a fused spur - it's a length of 2.5mm cable coming straight off a ring main, and therefore "protected" by a 30/32A breaker. If you promise not to label me as MB's long-lost brother, doesn't 433-02-01 say that

"the current carrying capacities Iz of the conductors of the circuit must be greater than or equal to the nominal current or current setting In of the overcurrent device"



And isn't the Iz of 2.5mm 27A at most?

I'll go away now and write out 100 times "I will not start quoting from the books Santa brought me"

 

[supersparks]

spurs dont HAVE to be fused....if you put a fuse inline of a spur it means you could have in infinate number of spurs off that spur
each switch would be looped off the ring, so each will be classed as a fitting, regs say you may have one spur per socket/fitting on ring.....

 

[ban-all-sheds]

Fair enough. It does seem odd though - is the assumption made that nobody would ever, without changing the cable size or adding a protective device, replace the single socket outlet with a double one?

It's all very well saying that the design current is less than Iz - I'm not sure it fits the safety principles of the regs though to allow a circuit where Iz < In just because Iz > Ib.

However - the good news is that Chris Rogers does not have to go to war with the builder over this.

I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist

 

[supersparks]

I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist
I will not become a reg fetishist[/quote]



keep em connin bas, i want 2 A4 sides!
your point is good though, common sence has been lost someware.....

 

[ban-all-sheds]

So which of these is OK:

1) Unfused 2.5mm spur from a 30/32A ring

2) Unfused 2.5mm leg from a 6mm 30/32A radial

3) Single outlet radial wired with 2.5mm coming from a 30/32A MCB

If the answer isn't the same to every one, why not?

 

[supersparks]

because, they assume that some loading will be on the ring, so say there is 10 amps of loading on the ring, it will be fine, this is also the reason you cant spur from a spur, like has been said countless times, the regs dont make sence,unfortunatly, people wont bother with rallying for change, for two simple reasons,
1) if they do it To regs, and there was a fire, it cant come back to you, you have abided, so people dont care,,,,

2) if you did it the common sence safe way it would likly mean a price increase, which means no firarri for everone

 

[breezer]

So which of these is OK:

1) Unfused 2.5mm spur from a 30/32A ring

2) Unfused 2.5mm leg from a 6mm 30/32A radial

3) Single outlet radial wired with 2.5mm coming from a 30/32A MCB

If the answer isn't the same to every one, why not?

1) 3) are ok

2 isnt because of the difference in cable size (you want to get 2 x 6mm cables AND a 2.5 mm cable into the back of a socket good luck)

I understand what you are asking 2 x 2.5 is 5mm so why is it ok, but not with the 6mm radial, some one may uprate the fuse and the fuse is there to protect the cable, guess which will go first if there is a short on the spur, it wont be the 6mm cable if some one uprates the fuse