MEM Gridwwitch 8000

[IMM]

You will finds that electrical and plumbing regs say the isolating switches/valve must be accessible. Once again, open to interpretation. Fitting a washing machine valve directly behind is a no, no. In new properties the valves, drain connections and electrical sockets are usually under the sink. It generally looks a mess down there, especially if the pipe/isolation valves are not fitted correctly. It is best to form a manifold fitted as high as possible, with the isolation valves facing downwards.

Fitting double pole switched sockets under a sink for all appliances would eliminate the need for a fused spur up top.

[Dave Plowman]

So you remove the plug from the appliance and hard wire it in? Bit of a pain if you need to move it for cleaning etc. If it's still plugged in but has a supplementary fuse in an FCU etc, you can bet your bottom dollar that it's still the fuse in the plug that goes...

FWIW, all that faffing around for the unlikely event of a fuse blowing - I've only ever had this happen once with kitchen appliances, and this required removal of the appliance from its 'housing' to fix the fault anyway, so being able to unplug it for servicing was far more of an advantage.

As regards being able to isolate kitchen appliances via a wall switch - again why bother? They all have off/on switches anyway. In the very unlikely event of this failing and the appliance had to be shut off at the same time urgently you could simply switch off the appropriate ring at the CU.

That's rather different. You need shut off valves, so you should situate them where they are easily accessible. And the same could be the case for the socket feeding the machine. It doesn't have to be behind the machine either.

[Christian McArdle]

You could use unfused 15A round pin sockets off a fused spur.

Myself, I agree that having the fuse in the plug isn't a problem. I used a

20A DP switch instead of an FCU to avoid having two fuses, and allowing a more pretty grid switch based solution that wouldn't take up too much space on the tiles.

Christian.

[Dave Plowman]

You don't need a switched socket at all. To isolate, simply unplug it.

[Dave Plowman]

So you cut off one plug merely to substitute another? Sounds like a solution to a problem that doesn't exist. Also, are suitable shuttered 15 amp sockets available, and at what cost?

That would make more sense if you really, really must have a separate switch for your appliances. But I think it's just making work for the sake of it - dedicated low situated sockets inside adjacent cupboards would be my way if a re-wire was undertaken.

[Jerry.]

We are back to placing the means of isolating in somewhere that is a/. not accessible and b/. only known to the property owner and the electrician who did the rewire and not to others - possibly even the lady of the house ! :~)

Also, in the case of washing machines etc. were there could be a fault involving leaking water would really want to either touch the unit before moving it or switch off a ring circuit rather than just a DP switch placed some where accessible ?

[Jerry.]

No, but it sounds like you are trying to ! Andy has interpreted the regs, correctly AIUI, how can you argue with the interpretation (Andy's interpretation) without arguing with Andy ?

[IMM]

You are jesting again!

[Dave Liquorice]

Cupboards have backs and sides and a services void at least a couple of inches deep behind the back panel. How do you mount/wire a socket to the, normally poorly supported, hardboard cupboard back?

When I get to doing the kitchen here It'll have below worktop unswitched sockets for appliances fed from a grid switch panel fitted with 20A DP switches in the room, fuses for each socket also mounted in the grid, I think not thought to hard about this yet...

[IMM]

In new properties the sockets are fixed to the side cupboard panels of the sink cupboard.

[Christian McArdle]

This is what I did, except there is no need for fuses in the grid switch. It is better to have only the fuse in the plug top. The grid switch is fed from a dedicated 32A 6mm radial and feeds only a w/m, d/w and t/d.

Christian.

[IMM]

So if the fuse blows you have to drag out an integrated appliance. If it is fitted correctly the socket should be accessible.

[Christian McArdle]

I'm not having both the switch AND an ugly socket with cable going through an ugly hole in the worktop. Generally speaking, if the fuse goes on an appliance, you want to drag it out to give at least a visual inspection for scorch marks before replacing the fuse.

Christian.

[Dave Plowman]

Wouldn't you anyway to fix the fault that caused the fuse to blow?

A fuse blowing for no reason is so rare as to be ignored in planning terms.

If you're going to the lengths of installing dedicated switches for appliances why not install new sockets in sensible positions too?

[Dave Plowman]

If you must mount it on the back, then a batten on to the wall wouldn't be too difficult?

Do you at the minute switch off *at the socket* (or unplug) all these appliances that you're going to provide this grid switch arrangement for? And have fuses blowing regularly enough to make it worthwhile?

If not, it seems like a lot of effort for something that is unlikely to be used - or needed.

[Dave Liquorice]

And 6mm from the gridswitch to the sockets? If you've dropped to 2.5mm from the gridswitch to socket that section is not properly protected by the 32A breaker...

[Christian McArdle]

Yes it is. It is protected from short circuit within the cable by having sufficiently low earth loop impedence. It is protected from overload by the

13A plug top fuse. It is no different from having unfused 2.5mm spurs from a ring main. You are permitted to assume that a single socket will only draw 13A and a double socket 20A, apparently, but must still provide short circuit protection, which is easy enough with a B32A MCB if the 2.5mm section is short.

Christian.

P.S. the 2.5mm actually runs from before the grid switch, as there is no way you can get two 6mm cables in one terminal.

2.5mm 2.5mm 6mm #--------SW-----SKT =======###-------SW-----SKT #--------SW-----SKT

## = junction box SW = 20A DP switch SKT = unswitched 13A single socket

The 2.5mm sections are kept short to reduce earth loop impedence at SKT to ensure that 160A can be reliably drawn on an earth fault at the furthest point.

Christian.

[IMM]

Does the MEM Gridswitch 8000 have trips or just rocker switches?

[Christian McArdle]

Not the fuses. However, I've often used isolating switches when funny things happen. Even simple events, like the washing machine making a funny noise the switches can be useful, particularly with modern appliances with software controlled switches that just ignore you, as they know "best".

I particularly hate those time delay door opening switches. I simply can't see the point of them. OK, so being locked when turned on, maybe. But having to wait 3 minutes for no discernable purpose, I cannot fathom. I frequently disconnect the lock when the machine gets well past warrantee.

Christian.

[Dave Liquorice]

But you also need a fing big hole to get the plug through into the cupboard. OK you can cut the supplied, moulded on jobbie off (invalidating any guarantee?) and thread the cable througha small hole. But if you need to move the machine out further than the length of cable you have to take the plug off...

Yes, young children, they fiddle. Even though ours know not to fiddle they occasionally forget. The washing machine is always switched off at the (above worktop) socket when not in use.