Definition. "EMERGENCY SWITCHING OFF. Opening operation of a switching device intended to remove electric power from an electrical installation to avert or alleviate a hazardous situation."

The switch is normally manually operated. It will not be automatic. So the action must be simple and singular. A "single action only". 465.3.

"Too many people focussing on one single action, to me its not the single action of what your hand does its the single operating action of one electrical accessory that latches in the off position and isolates all forms of energy etc from the installation/equipment/machine."

The first sentence of 465.3  deals with the mechanics/electrics of the switching device. The second sentence deals with the human intervention to actually operate the switching device.

MCG 25A 2 Pole 230V Fireman's Switch IP65 (FMS 25/2) | CEF

Z.

I think a fire fighter's switch is acting more like an isolator than an emergency switch. A fire fighter will likely activate it as a precaution before squiring water everywhere. As opposed to "someone is getting an electric shock from this neon sign, quick turn it off!".

wallywombat said:

I think a fire fighter's switch is acting more like an isolator than an emergency switch.

In BS 7671, yes, but that's not the case where other standards refer to BS 7671, and specify the switch for other purposes. Which is, I think, where GTB is coming from?

Morning Graham,

Yes, You know how we use a physical " Fire Fighters" switch as an "Public Emergency Switching Device" so it is mounted at a height no greater than 2M from finished floor height. We fit a piece of red label material over the words "Fire Fighters Switch" to keep the pedantic inspectors happy so they are hidden, and have a large yellow back ground behind the physical switch so its red against yellow with the appropriate engraved words on that yellow background in large red font. The emergency switch is for use by the public hence the Max height its mounted at as they shouldnt have or need a firefighters axe on them to activate it.

Cheers GTB

Well the definition of 'emergency switching off' in Part 2 of BS7671 is quite broad and does not even require the hazardous situation to be electrical in nature - although the note to 537.3.3 seems to say that it does.  I'm not sure I get the subtlety of your distinction Graham.

'My consumer unit has started fizzing and smoking a bit and it seems to be getting worse'.  This would seem to fall under the definition of needing to be 'emergency switched off' to me.....

So it's not intended for use by very short people or the disabled then?

Z.

Camper van catches fire as driver is filling it up at Morrisons petrol station in Weymouth | Daily Mail Online

Z.

Zoomup, I said its for use by the public!,

There are other emergency stop devices provided elsewhere for suitabl;y trained and competent staff to operate, and if it is a self service facility the console staff will or should have operated the emergency stop they have rapid access to before a member of the public accesess the one for use by the public.

My wife, is only 4ft 11, and it would take a very brave man for fear of physical harm to call her anywhere near being short!

Also my words defined the switch at being no greater than 2M from finished ground/floor level.

Zoomup,

Dont believe everything you read in the papers!!, maybe the camper van was already on fire before it arrived in the filling station..........................

GTB

Im still waiting on that NICEIC inspector to draw me or show me an example of a lever operated device that you dont grab then push up or down?

When I was small, out shopping with my mum, I noticed that the on-off switch on bacon slicer (a long toggle swicth) was to my mind 'upside down' - the grocer pushed it up to start the machine and down to stop it. I asked my mum why it was upside down and she said she didn't know but perhaps I should ask the shopkeeper .... so I did ... and was told it was for safety  (1970s style) - because in an emergency it was quicker and easier just to slam a hand down at the swich, rater than position a hand underneath and lift, it was safer to have it down for off. So I reckon that's an example of a lever type actuator you can just hit down without having to specifically grip first.

   - Andy.