Ohh no not again - green box's

[lingmoor]

so are people saying that if it opens on actuation of fire alarm, fails safe to open in the event of power failure, there's a double pole red call point next to the fire exit door(so if the fire alarm fails it will still open)...it still needs a green box?

I wouldn't ask for it

edit...maybe I read the op's question wrong

[Wiz]

so are people saying that if it opens on actuation of fire alarm, fails safe to open in the event of power failure, there's a double pole red call point next to the fire exit door(so if the fire alarm fails it will still open)...it still needs a green box?

I wouldn't ask for it

edit...maybe I read the op's question wrong

Lingmoor, in a typical set-up, the operation of a fire alarm call point sends a signal back to the fire alarm control panel, the fire alarm control panel then sends a signal back to a relay which disconnects the power to a electromagnetic door lock causing the door lock to release. None of this is fail-safe, and can't easily be made fail-safe. the typical fire alarm call point has no direct interconnection with the electromagnetic door lock.

If you rely purely on the operation of the fire alarm system to release a locked door then you have a set-up with many potential failure points and no way of releasing the door in an emergency if the set-up does fail.

A correctly installed EDR switch (green box) is about as good as you can get in providing a system where you can always effect escape through an electromagnetically locked door (fitted with fail-safe lock).

[lingmoor]

Wiz

yes I mis-read the OP's post

I was talking about double pole fire alarm call points that have a direct connection with the electromagnet..same as a green box

[Wiz]

Wiz

yes I mis-read the OP's post

I was talking about double pole fire alarm call points that have a direct connection with the electromagnet..same as a green box

In my 30+ years in the business, I have not seen an installation using a fire alarm call point as also an Emergency Door Release switch. It sounds like it might be a good idea although the BS don't recognise such a set up. The switching of the the electromagnetic door lock would have to be double-pole to suit current BS, so that means the 'combined' switch would have to be triple-pole (at least) to also accommodate the signalling to the fire alarm system. And I wonder if there would be any confusion regarding people expecting to see a 'green box' EDR and only finding a fire alarm mcp?

[nearlythere]

Morning all and a great weekend for Irish rugby it has been. 100% success rate for the four provinces.

Anyway, following a comment in an engineers report that the operation of a green box should actuate the fire warning system I have looked through BS7273 Pt4 and take from what I have read, or not read, what I have always assumed, that this is not the case.

Am I still correct?

[Paul2886]

You are right. Have never heard of an green EDR activating the fire alarm system. Ask him where he accessed his information.

[nearlythere]

You are right. Have never heard of an green EDR activating the fire alarm system. Ask him where he accessed his information.

Knowing the outfit who reported it Paul I would think his information came from up the U bend. This "Registered" outfit wired a fire alarm system with flat T&E.

[Paul2886]

Well there you are NT....say no more

[AnthonyB]

It's an emergency door release not a fire door release, you might need to use the exit when sounding the alarm is not required or even counter productive - perhaps they were getting mixed up and meant that a fire warning system should release the door.


They will be saying next that a fire alarm break glass should set off all the sprinklers (because that's what happens on TV....)

[nearlythere]

perhaps they were getting mixed up and meant that a fire warning system should release the door.

No. It was the green box.