Help With Sound Limiting Equipment

[S-elect]

Hello all,

I've got too fit some sound limiting equipment for a friend to win some more work as a good gesture. The premises is a small village hall and I've never fitted sound limiting equipment. The equipment is made by electrovision part no G920a, cheapish looking at the pictures of the product. I've done lots of contractor controls for lighting and distribution power/emergency stop circuits. I'm going to break the ring so I've got two legs from the sockets on the output side of the contactor and the ring pair from the board on the input side of the contactor. The control circuit for the contactor is via a fused spur from the ring cables from the db before they get tithe contactor. A microphones comes with the equipment I'm wiring with cat 5 cable.

I will be putting each end of the ring in its own terminal, my question is though is it acceptable one the sound has gone above the set db level and opens the contactor to kill supply to the sockets, the ring in will be open end for 5 second in the equipment, would this class as a deviation?

Just wondered if anyone has experience in this or experienced, or any pointers would be great help

Many thanks

Sam

 

[Essex1]

I don't get it. If you are terminating all the line conductors into one contactor. Once the sound kills the power to the contactor all the line conductors will be disconnected at the same time, no?

 

[S-elect]

Yeah your right in what your saying but because it's 4 pole contactor I'm putting the two legs from the db into one side of the contactor which is permanently live and is making a continuous ring but when the equipment opens the contactor because the two ring cables from the board will be open because I've got them in individual terminals, I have tried uploading a quick sketch but can't for some reason. Which means all the time the equipment is healthy it's a continuous ring from db. I did think about putting the two live and neutral cores together so I would only be using to poles each side of the contactor but this would be incorrect I feel, interlinking the ring

Appreciate your help Essex 1, sorry can't be more clear but I'm just reading from the instructions which are poor.

Cheers

Sam

 

[Essex1]

So if you have a 4 pole contractor that is 2 lives and 2 neutrals in the top and 2 lives and neutrals in the bottom.

 

[Doc Hudson]

Why do you need to kill the whole ring, Can't the hall stipulate that certain socket(s) are used for any audio equipment and just kill those when if the sound is too loud. Also I would have thought it is only amplifier(s) you need to disconnect not any other associated equipment, such as lighting effects.

Doc H.  

 

[Lurch]

Usually I would try and just use these to just kill the outputs from the amps rather than just killing the power to them as this can shorten the lives of the amps and speakers pretty swiftly.

 

[Doc Hudson]

Usually I would try and just use these to just kill the outputs from the amps rather than just killing the power to them as this can shorten the lives of the amps and speakers pretty swiftly.

Which is what I was trying to say, there could be all sorts of equipment connect to the ring that is not designed to be repeatedly powered off and on. I cannot see any logical reason why you would want to kill a whole ring.

Doc H.

 

[chris_k]

Electrovision stuff is a bit nasty. Formula sound is the stuff to use. Anyway.

A 4 pole contactor is provided so you have various options. You can connect a 3p+n circuit, two single phase circuits where l+n are switched or 4 circuits where live is switched.

I usually just use the contactor to switch the stage socket(s) or where the dj will set up.

 

[S-elect]

I understand all the things you are saying but the hall has had a electrician previous to me put in 6no sockets dedicated to stage equipment only, my concern is their is a delay option and it suggests 5 seconds until unit re-energises, how much damage is this going to do to equipment repeated going on and off? And yes Essex 1 we are on the same wave length. I'm not too clued up on AV equipment but I'm sure it won't like beig switched on and off especially with djs! Apparently this equipment is suites towards this and the hall has required it this way, I will make sure my certificate states I did not design. I'm not very fond of these jobs to get jobs, the previous electrician walked away I think.

Thanks

Sam

 

[Doc Hudson]

I would have thought that providing the hall make it clear to all using the venue that any sound equipment must be connected via certain sockets, then when it has tripped off once, if the DJ his worried about his kit they will ensure that they keep the volume down to make sure it is not turned off again. Its not then the electrician or the halls problem if Mr DJ keeps playing his music too loud and thus has power repeatedly off and on.

Doc H.

 

[chris_k]

Sadly some of this kit is so badly set up (too sensitive) that just a crowd singing happy birthday to someone on stage can trigger it. Most use a traffic light system to indicate system state, place this where the dj can see it. Not behind the bar like i saw on one install!

On the higher end systems the audio signal is cut or attenuated to the amps (in nightclubs) but in your case it controls power to kit brought in.

Most decent amps have relays on the outputs so turning off  and on again shouldnt present an issue. Although repeatedly doing this aint good. However if the dj trips it out repeatedly and damages his kit its his own fault.

Set the delay to 7 secs. this is enough time to enable the dj / sound guy to mute the amps or desk and make it embarrassing for him when the crowd stares at him when it goes off.

They`ll just run an extension from the kitchen behind the stage after a bit anyway

 

[S-elect]

Thank you for all your help, I will mount the kit on stage sod just can see it, I will install as their design and label up accordingly on what socket is controlled by this equipment. I can see it being a pain having to go back up there and set the db limit so high it won't work anyway. Will set to 7 seconds thanks Chris k. I will let you know how I get on!

Thanks

Sam