E
Engineer54
Yeah, ...It's called wiring through a relay!!!
yeah i gathered that but not having fitted one before I need to know of a make/manufacture that I can contact and get one, do you have a manufacturer or model of one that will do the job please?
Here's what you are looking for... Products I think a lot of Electricians get quite annoyed on here when individuals join and message just a few times looking for information and tips or "tricks of the trade" then don't even click the thanks button before disappearing only to resurface a year later looking for more Trade information to save on the costs associated with hiring the services of a tradesman and do a "DIY" especially when it involves Industrial locations and uses...a lot of the time the person responding may spend a number of hours making telephone calls or reading up Data sheets etc and may not even get a response from the original enquirer after posting a solution.... this is why sometimes apparently rude or unhelpful comments may appear...
I can appreciate this and I appreciate the help that I receive on here but just to let you know that I am a fully qualified electrician and have been in the trade on and off for the last 20 years and I only need help occasionally when I get jobs that I know nothing about like this, I also thank the people that do help with the answer to the question that I ask and am fully appreciative of the time it takes for them to get the answer to me.
So thank you for taking the time to find me the answer.
S
Sintra
You may need to fit an interface to the FA system in the proximity of the solenoid valve. This will give you a set of NO / NC contacts to break the solenoid supply through.
Are there any other measures fitted to isolate the solenoid eg emergency gas shut offs etc.
I have no idea about this as I have no idea about the fire alarm panel, Basically I was talking to the guys who installed the fire alarm and they have a relay next to the gas shut off valve that operates when the fire alarm goes off but the output from the relay is only 24v, when I asked them how to connect this to the shut off valve all I got was "its not my problem mate" and "its not my job to connect someone else's equipment to the alarm"
just ask them to swap the interface at the gas shut off for a 230v one, then your more than half way there.
But having said that they say its not there job , they need to prove cause and effect, so its in there best interests to have a bit input into making sure it interfaces correctly. How can they have done the demo to the client and fire officer and issued certs if it hasnt shut the gas off.
Best stop now starting to go off on a tangent now, need to calm down, too much drink in me lol.
GLHF
But having said that they say its not there job , they need to prove cause and effect, so its in there best interests to have a bit input into making sure it interfaces correctly. How can they have done the demo to the client and fire officer and issued certs if it hasnt shut the gas off.
Best stop now starting to go off on a tangent now, need to calm down, too much drink in me lol.
GLHF
M
MDJ
As engineer54 mentioned a relay is the way, very straight forward, you want a 240 volt relay with a 24 volt dc coil, when the bells ring the relay coil is energised and the supply to the gas valve is broken, how you energise the coil is a matter of a couple of ways, via an alarm relay in the panel or by a sounder itself, the latter not so good as you may need a diode doing it this way to ensure the panel doesnt go into fault.
S
Sintra
The interface fitted will be fine as it will be the relay coil that is operated by the 24V from the FA panel. The switching contacts will be volt free and will more than likely be 10A rated. Use the C & NC terminals to break the solenoid supply.
At the moment all I have is the emergency gas shut off valve which I have energised through the means of a FCU (TEMPORARY) until I figure out the correct way of connecting it through the fire alarm.
There will be an Estop next to the valve once configured correctly
The interface that you talk of is what I am looking for, I'm thinking this should be simple once I find the correct piece of hardware to go between the two, just need a make and model, I have tried the link suggested above but can't get on their website.
I'm in work tomorrow so i'll get some photos of the exact setup and post on here
M
MDJ
no need to complecate it though bud, a relay is a very very easy way to get the job done and used a hell of a lot for this type of circuit control regarding gas valves.
This is what I am looking for, would you be able to direct me to a link that shows this please so I can get one ordered, many thanks
S
Sintra
Right ok what have the FA guys fitted that you are talking about in post #9 if it's not an interface.
what about this? looks like it'd do the job
774-306 PNOZ/X2.1/24V - PILZ - RELAY, SAFETY, 2NO, 24VAC/DC | Farnell United Kingdom
774-306 PNOZ/X2.1/24V - PILZ - RELAY, SAFETY, 2NO, 24VAC/DC | Farnell United Kingdom
S
Sintra
Just another pointer mate all cabling on a FA system has to be monitored for OC SC etc. using a non specific part can sometimes prove difficult.
You still haven't clarified what the FA guys fitted beside your solenoid.
I'll post some photos up tomorrow of exactly what is there, they didn't fit the solenoid the gas men did, the FA guys have just brought their cable next to it which comes from a 24v relay box
S
Sintra
Ok post pics as that is all you should need. The solenoid might even have an auxiliary connection. Please take pics of all parts of the puzzle and we will get you sorted.
T
tazz
Hopefully a diagram might help any 24v coiled relay with mains rated 10A contacts will do the job,
Perfect, thank you very much
T
tino1888
We wire this type if setup in all schools nowadays. Usually for boilerhouse, kitchens, classrooms. If you have a ventilation system ie: supply/ extract fans supplying the warehouse it may need coiled with a fan proven switch.
Failing that as previous post have said. Wire in a 24v relay, with 240v contacts..
There's a whole host of building control regulations regarding gas solenoids now.
Most units we fit/wire in the classrooms have a leak pressure switch on the gas solenoid as well. just in case the kids leave there Bunsen burners on
Failing that as previous post have said. Wire in a 24v relay, with 240v contacts..
There's a whole host of building control regulations regarding gas solenoids now.
Most units we fit/wire in the classrooms have a leak pressure switch on the gas solenoid as well. just in case the kids leave there Bunsen burners on
D
Darkwood
This suggested set-up isn't fail safe assuming the alarm is acting on a real fire situation then as soon as this cable looses supply and/or is damaged by fire the solenoid will open again letting gas through, although im unsure of codes of practices here i feel its not as simple as it sounds, if op has a output relay then volts free then an external power supply with independant battery back-up should be holding the relay open and the failure of the independant supply or alarm activation will close the valve ... any fire damage or general damage to the cable will then see the valve close.
Its possible dependant on the alarm panel to use the internal 24v supply to eliminate the need for a external relay and power source but this will be dependant on the size of the solenoid and the 24v output max current rating.
As already mentioned it may be the case that safety relays or specific interface boards should be used and another issue is the reset and indication system the gas valve shouldn't re-energise automatically IMHO without a operator reset been applied but il reserve this judgement for now as resetting the panel could be classed as a operator reset, also a test function should be implemented into the design and if done and an over-ride as you dont want to loose the gas and have to prime all the boilers and burners everytime you do a test on the alarm although it should be subject to its own testing routine.
Last edited by a moderator:
D
Darkwood
@ the OP ..... I suggest you wise up on fire alarm installation regs and i dont mean BS 7671, you need to purchase the relevant reg's, i would tread very carefully here as you could be putting yourself in a position of responsibilty if the system you fit fails, worse case lives could be lost and you need to proof the system you fitted was in full compliance with the relevent fire/safety regulations.
Im a little supprised at the ease of some members here to give many suggestions without considering they could be suggesting a system that falls far short of what is required, i believe tino1888 hit the preverbial nail on the head with his post #23 where as such hes the only one to warn of a whole host of regulations you may have to comply to.
My suggestion is Sub a Fire Alarm company in who will be knowledged in this area, if their are not its on their shoulders not yours.
Im a little supprised at the ease of some members here to give many suggestions without considering they could be suggesting a system that falls far short of what is required, i believe tino1888 hit the preverbial nail on the head with his post #23 where as such hes the only one to warn of a whole host of regulations you may have to comply to.
My suggestion is Sub a Fire Alarm company in who will be knowledged in this area, if their are not its on their shoulders not yours.
M
MDJ
your absolutely right fella on all points, the only thing I would actually add, is the first method fed from the fire relay in the panel wouldn't be an issue, the gas will not switch back on if the bells stop ringing by using the silence button, it would only switch back on if the panel was reset from alarm mode, and the alarm should never be reset unless everything checks out okay and the persons in the building in charge of this would know through training not to reset a system unless conformation it is safe to do so has been established.
T
tazz
The diagram i have drawn here is a stadard fail closed system as required by BS5839 part 1 (monitored control), if you take note on the wiring you can see the relay is energised. For any reason power is lost to the relay ie damaged cable the solenoid will close. In the event of a fire condition again the power is removed. Other methods of shutdown ie pressure will be down to the statury risk assessment undertaken, or local authority guidlines.
M
MDJ
a good diagram actually tazz, I have wired valves this way you have drawn many times hence my initial comment about the relay, cheers for the drawing bud.
T
tino1888
Sometimes a aux contact on solenoids are also added to indicate the position of the valve.
Wiring anything to do with Gas installations is always tricky.
I even had a call from my aunt tonight asking for a fcu for a new combi as the gas guy 'won't pass it'.. Even thou I know there will be no bonding, labelling, or electrical testing prior to me fitting a fcu.
Wiring anything to do with Gas installations is always tricky.
I even had a call from my aunt tonight asking for a fcu for a new combi as the gas guy 'won't pass it'.. Even thou I know there will be no bonding, labelling, or electrical testing prior to me fitting a fcu.
T
tazz
This is where designers, Architecs and local authorities all sit down and make a specifications. Once all specialist proffessions are sing from the same hyme sheet we design the fire alarm and switch gear to suit, as you can appreciate, this is usually not off the shelf gear so has to be designed and all metal work, and control panels made to order.
I'm surprised a 20 year experienced spark is asking this. Get a hold of the fire alarm guy on site and hand him a sheet of paper and a pen. He will sketch the circuit in minutes. Write back to [email protected] for a diagram.
Cheers
Les (ex-F/E Lecturer)
Cheers
Les (ex-F/E Lecturer)
Last edited:
OFFICIAL SPONSORS
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc
Advert
Thread starter
robbo777
-
- Joined
Thread Information
Advert
Thread statistics
Advert
TrueNAS JBOD Storage Server
-
-
Understanding TrueNAS JBOD Servers: A Comprehensive Guide- Started by Dan
- Replies: 8
-
