gas interface

[fireman22]

hi we are a firm of electricians, got a customer who has a solinoid gas valve fed via an emergency stop button near the exit to the kitchen, its a small club. He want us to link the fire alarm via this emergency stop which is not a problem to us as we thought of just picking up the 24 volt switched supply from the sounder circuit and just adding a 24 volt relay with 240 volt rated contacts job done. However i am sure i have seen on the market but dont know where a purpose made interface box with terminals for mains in, 240 volt solinoid valve out, fire alarm switch input and an emergency stop on the front of it???? any ideas where from.
paul

 

[RF Lighting]

Nope, sorry.

We always do like you say and fit a relay fed either of the panel aux contacts, or from the sounder circuit on conventional systems.

If the fire alarm system is an analogue addressable system them we would fit an interface unit, as there often is only loop driven sounders.

If you feed a relay off the sounder circuit of a conventional fire alarm system, don't forget you must polarise and supress the relay.

 

[breezer]

in4007 diodes work wonders

 

[Adam_151]

in4007 diodes work wonders

1N4007 ?

 

[breezer]

close enough

 

[croydoncorgi]

Presumably, the stop button is connected to a 'commercial kitchen gas control' which turns off the gas in the event of a ventilation system failure (part of BSwhatever requirements).

Just controlling the gas supply from the fire alarm MIGHT be leaving the job half-done (dunno- not a fire safety specialist). You might want to interlock the vent fan(s) with the fire alarm too, especially if there are INTAKE fans pushing air into the kitchen which might ventilate a fire and / or drive smoke out into the rest of the building. Seek proper professional advice! (Maybe the Fire Service would give it FoC). Or call Duomo, suppliers of gas controls.

 

[Agile]

I do hope that you are CORGI registered for commercial catering and pipework!

The slam shut solenoid gas valve is part of the gas safety system in the kitchen. Its a safety device!

Whilst I agree that interrupting the supply automatically sounds like a good idea on account of the function but I have not heard of any requirement within the gas Safety and Use Regulations.

If I was involved I would want to have CORGI approval in writing before doing that modification.

Tony

 

[fireman22]

agile
no we are niceic electrical firm, not doing any pipework or fitting any gas.
we have been asked to interlink the existing emergency stop button 240 volt in the fire alarm system so it will shut automatically as per my original post

 

[Spark123]

I am inclined to say run the 240v NC stop circuit to an interposing relay fed as RF lighting says above. Don't forget plenty of labels on the insterposing relay enclosure, voltages and supplies etc, also don't underestimate how big a shock you can get from a 24v bell circuit!!

 

[Job_n_knock]

I do a lot of work in Superstores, and they all have a system whereby in the event of a Fire Alarm, The gas shut-off valve operates and dampers shut the Air supply AND extract/return air ducts. Its standard procedure and also common sense.

 

[RF Lighting]

I do a lot of work in Superstores, and they all have a system whereby in the event of a Fire Alarm, The gas shut-off valve operates and dampers shut the Air supply AND extract/return air ducts. Its standard procedure and also common sense.

We do work in commercial kitchens, and have been advised by a fire officer to leave extract fans running, but kill intake fans, friers, and gas shut off valve(s) in the event of a fire alarm.

Apparently this is to try and clear the smoke without fueling the fire (too much)