Could it be argued that 463.1.3 requires a separate switch for items like an oven, hob, refrigerator or washing machine etc. where the appliance has no means of external isolation/control except those on itself? Or are functional controls on the appliances adequate and sufficient?
Z.
I don't see it like that at all Z. It is simply saying that a power-using item must be able to be switched off. Appliances that are plugged in obviously have this, and a fridge built-in does not. It is not saying anything about an emergency (as you quote) or even isolation for cleaning or maintenance. Functional switching is simply turning something on or off. I rather hope the grid switch turning off every kitchen item has died the death, If you have a fire surely you want to turn off all the electricity so the CU or whatever is perfectly adequate as it provides 2 pole isolation. Then you can get the hose out or whatever. It is very wise to have a fire blanket in the kitchen, but that is not a BS7671 scope, it belongs in the BR.
What about a modern dish washer that I saw today that has controls on the top edge of the bottom hinged door. Once a cycle has started the door is locked shut until the end of the cycle. Access to the functional switching is then impossible until the cycle has ended and the door opened.
And...............the supply for the dish washer is from a cooker circuit protected by a B32 M.C.B. The dish washer has no local switch at all. If it is plugged into a socket, the socket must be behind the appliance and is inaccessible.
But the cooker switch does turn it off as well as the hob and oven. So we have three appliances connected to the cooker circuit where one is not obviously switched.
Would you expect a cooker switch to control a dishwasher?
In a panic, such as when an appliance catches fire or tries to flood the floor, can we be cool headed enough to turn off at the consumer unit? And what if that is situated say in the garage, and not conveniently situated. What if we accidently turn off the lights as well at night thus introducing an additional hazard during an emergency like an appliance fire or a flooding washing machine
Local isolation is important.
Z.
What about a modern dish washer that I saw today that has controls on the top edge of the bottom hinged door. Once a cycle has started the door is locked shut until the end of the cycle. Access to the functional switching is then impossible until the cycle has ended and the door opened.
And...............the supply for the dish washer is from a cooker circuit protected by a B32 M.C.B. The dish washer has no local switch at all. If it is plugged into a socket, the socket must be behind the appliance and is inaccessible.
But the cooker switch does turn it off as well as the hob and oven. So we have three appliances connected to the cooker circuit where one is not obviously switched.
Would you expect a cooker switch to control a dishwasher?
In a panic, such as when an appliance catches fire or tries to flood the floor, can we be cool headed enough to turn off at the consumer unit? And what if that is situated say in the garage, and not conveniently situated. What if we accidently turn off the lights as well at night thus introducing an additional hazard during an emergency like an appliance fire or a flooding washing machine
Local isolation is important.
Z.
Isolation is not functional switching Z, you are confusing the two. Whilst your kitchen in question is unusual, it is not contrary to BS7671, and I really cannot see that cooker switch being used for functional switching. It is used to isolate the connected appliances, and if you think it is not clear why not add a label saying what it does isolate? I'm sure you have a suitable label maker for CU circuit labels etc. I have a nice Dymo one that has modes to do just that. Others may note the diversified load!
What about a modern dish washer that I saw today that has controls on the top edge of the bottom hinged door. Once a cycle has started the door is locked shut until the end of the cycle.
You might find that if the supply is interrupted, the door remains locked shut. That certainly seems to be the case with clothes washing machines.
There really ought to be a means of terminating the programme early. If not, that seems to be v. poor design, but nothing to do with BS 7671.
What about a modern dish washer that I saw today that has controls on the top edge of the bottom hinged door. Once a cycle has started the door is locked shut until the end of the cycle. Access to the functional switching is then impossible until the cycle has ended and the door opened.
That's interesting. Which make & model if you don't mind me asking? Most dishwashers permit the door to be opened throughout the cycle, but that doesn't mean they all do of course.
What does the manufacturer recommend in terms of installation and user-accessible controls or means of isolation?
And...............the supply for the dish washer is from a cooker circuit protected by a B32 M.C.B. The dish washer has no local switch at all. If it is plugged into a socket, the socket must be behind the appliance and is inaccessible.
The socket-outlet does not have to be behind the appliance. In our kitchen (well in fact, house full stop), only one appliance has its fixed socket-outlet behind (and inaccessible), and that appliance is on its own circuit.
The socket outlet is not visible for the dish washer. It is hidden, and is not in an adjacent kitchen unit either.
I believe that the dish washer maker is Danish, I only had a quick look at it and got the info. from the home owner I will have more info. when I go back. I will have another look. The machine is made for European countries as it has both a 13 Amp plug and a European two pin plug as options illustrated on the instruction book.
Yes I am aware of the difference between isolation and functional switching David.
460 says it deals with; "Non-automatic LOCAL and remote isolation and switching measures for the PREVENTION OR REMOVAL OF DANGERS associated with electrical installations OR ELECTRICALLY POWERED EQUIPMENT."
So, if I find my washing machine is issuing smoke I would quickly like to isolate it by means of an obvious, convenient, local switch. This is best positioned close to the appliance. Also, visitors may be in need of turning off dangerous appliances, so they may not know where the consumer unit is located. A local isolating switch is essential for every appliance.
Z.
So, if I find my washing machine is issuing smoke I would quickly like to isolate it by means of an obvious, convenient, local switch.
Ah yes. A switch which is on the wall above, but behind the machine. Mind the flames when you try to reach it!
Sorry, Zoomy, I think that we all share your concern, but you are not winning this one. :-)
To the side of the appliance Chris, not necessarily above it. Just as we would not have a hob switch immediately above it for obvious reasons.
Z.
Here's a thing. With the hob, oven and dish washer all supplied by the same circuit, with just one switch, and say the dishwasher become faulty and trips off the circuit R.C.D. how can it be isolated on its own. It can not, so many circuits are lost as the consumer unit is a split load type. Much inconvenience....
Z.
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