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Topic Title: Release of Secure Access Control Door
Topic Summary: What are the specific requirements to provide release of a secure access control door under fire conditions
Created On: 21 November 2017 12:10 PM
Status: Read Only
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 21 November 2017 12:10 PM
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skeltoa

Posts: 15
Joined: 28 October 2002

Trying to get a definite understanding of what is required for releasing an access control door on an escape route that is designed not to fail safe open on fire.

To maintain security it does not fail safe open under fire condition.

To egress there is a push-to-exit button and break glass. However, does it also need a mechanical means of overriding the lock (i.e handle) or is the break glass sufficient as this will cut the power to the lock?

 21 November 2017 01:40 PM
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alancapon

Posts: 6937
Joined: 27 December 2005

That will depend on whether the lock fails to the "open" position if you remove its power. My understanding of BS7273-4:2015 is that the door would need to be considered in the fire risk assessment for the building, especially if it remains locked when the fire alarm operates.

Reagrds,

Alan.
 21 November 2017 03:06 PM
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pww235

Posts: 198
Joined: 03 April 2014

AFAIK, if there's a mechanical means of overriding the electric lock (i.e. handle operation) then the green break glass and push to exit can be omitted as for egress the handle is used.
 21 November 2017 04:22 PM
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skeltoa

Posts: 15
Joined: 28 October 2002

The door would fail open on removal of supply.

With regard a door handle my question is if this is not included would this still be ok with break glass/p-t-e only.
 21 November 2017 05:16 PM
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OMS

Posts: 22428
Joined: 23 March 2004

I'd say that the break glass unit needs to act directly on the lock (ie not via a control module) and the lock must be a fail to safe type

If not then put a keyless door bar or push pad on the secure side for emergency egress purposes

Regards

OMS

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Let the wind blow you, across a big floor.
 21 November 2017 09:42 PM
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alancapon

Posts: 6937
Joined: 27 December 2005

Originally posted by: OMS
. . . I'd say that the break glass unit needs to act directly on the lock (ie not via a control module) and the lock must be a fail to safe type . .

I agree, and that is roughly as per section 11.2 of the standard I referenced earlier. It states that it should be connected in series with the power supply to the release mechanism.

Regards,

Alan.
 06 December 2017 02:04 PM
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skeltoa

Posts: 15
Joined: 28 October 2002

Thanks for the responses. So to clarify I don't need the door bar or push pad if the break glass acts directly on the lock.
 06 December 2017 02:47 PM
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OMS

Posts: 22428
Joined: 23 March 2004

Generally no - but you do need to have considered all possible failure modes of the lock and the associated system - if there is any risk of someone ending up locked in, then you need a means of opening that door without the use of a key or tool - ie a panic bar or push pad release

Regards

OMS

-------------------------
Let the wind blow you, across a big floor.
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