Sound Board to Light Controls
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izak
Senior Member
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- Springfield, MO
Re: Sound Board to Light Controls
mmmmm... isolation transformer?
i was reading in a thread earlier today where someone described a setup that could work...
mmmmm... isolation transformer?
i was reading in a thread earlier today where someone described a setup that could work...
Re: Sound Board to Light Controls
Check this information out. It should help.
http://www.arx.com.au/FAQ_Hums.htm
Check this information out. It should help.
http://www.arx.com.au/FAQ_Hums.htm
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
Re: Sound Board to Light Controls
I wish you would have asked here first before doing that job.
The information in the link that Bob gives is absolutely correct. Dimmers should be far away from audio systems, should never share even a panel and the grounds should be completely serarate from the audio grounds. Keep all audio wiring far away from the lighting wiring and the lighting itself.
While on the subject of grounding, it doesn't sound like the sound system itself is done correctly either. I've said in the past that I'm not a fan of congregation members doing audio work. This seems to be standard procedure for some churches and while the intentions are good the results are usually a disaster like what you have.
Unless your education and experience includes sound systems I would refer the job to a qualified contractor.
-Hal
I wish you would have asked here first before doing that job.
The information in the link that Bob gives is absolutely correct. Dimmers should be far away from audio systems, should never share even a panel and the grounds should be completely serarate from the audio grounds. Keep all audio wiring far away from the lighting wiring and the lighting itself.
While on the subject of grounding, it doesn't sound like the sound system itself is done correctly either. I've said in the past that I'm not a fan of congregation members doing audio work. This seems to be standard procedure for some churches and while the intentions are good the results are usually a disaster like what you have.
Unless your education and experience includes sound systems I would refer the job to a qualified contractor.
-Hal
Re: Sound Board to Light Controls
Just read your article about humm and so forth.
If we used his recommendation we would rip out the electrical wiring in both churchs and import a second power supply from another city. Are you for real did you really believe what he or she stated.
He states half way down the article page 1 quote these mains should be drawn from from electrically seperate outlets ( Which they are)Usually in medium ( Ours is rather small 4 speakers period)will be iether seperatedeither on a different circuit ( ALL LIGHTING IS ON ITS OWN CIRCUITS)or in the ideal case,by completely seperated and isolated mains and earthing systems. Nonsense. I have been to massive stage functions where we just bust in to a 3 phase system run in temps for 3 days with no troubles with the lighting panel physically mounted over the lighting panels and vice versea
Just read your article about humm and so forth.
If we used his recommendation we would rip out the electrical wiring in both churchs and import a second power supply from another city. Are you for real did you really believe what he or she stated.
He states half way down the article page 1 quote these mains should be drawn from from electrically seperate outlets ( Which they are)Usually in medium ( Ours is rather small 4 speakers period)will be iether seperatedeither on a different circuit ( ALL LIGHTING IS ON ITS OWN CIRCUITS)or in the ideal case,by completely seperated and isolated mains and earthing systems. Nonsense. I have been to massive stage functions where we just bust in to a 3 phase system run in temps for 3 days with no troubles with the lighting panel physically mounted over the lighting panels and vice versea
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Sound Board to Light Controls
Straps what you don't understand is with professional lighting control systems the actual dimmers are in a rack or mounted up by the fixtures, and are controlled via a low voltage cable that does not have enough current to bleed over into the sound system. Plus these professional lighting systems will have filters in the dimmers that trap the noise the dimmers make. But using a common dimmer that is intended to be used to control regular lighting will not have these filters and will cause allot of noise in a sound system when the circuits are not kept separate. What I mean by this is the PA system must be fed from it's own circuits that do not have any other circuits on them and these circuits should be installed in a metal conduit that will help from getting any induced noise in them. Also what concerns me is when you said:
1. are the neutrals for each circuit also running with each circuit conductor?
2. are the neutrals for each switch leg running to the lights ran in the same conduit or cable Assembly from the dimmers?
You should run the power feed to the lights separate from the power feed to the sound equipment. audio cables must be kept a good distance from the power feeds also. I do install professional sound and lighting systems and have been certified by Electro-Voice for about 15 years to do there installs. But it doesn't matter how much we know as there is always something different in each installation that takes experience to know how to solve a problem.
But I think I see other problems with this installation too
What kind of wires did you use for these circuit conductors?
You stated:
You made the statement:
I think you need to seek some hands on help where someone can see what you have and apply the right corrections.
Good luck
Straps what you don't understand is with professional lighting control systems the actual dimmers are in a rack or mounted up by the fixtures, and are controlled via a low voltage cable that does not have enough current to bleed over into the sound system. Plus these professional lighting systems will have filters in the dimmers that trap the noise the dimmers make. But using a common dimmer that is intended to be used to control regular lighting will not have these filters and will cause allot of noise in a sound system when the circuits are not kept separate. What I mean by this is the PA system must be fed from it's own circuits that do not have any other circuits on them and these circuits should be installed in a metal conduit that will help from getting any induced noise in them. Also what concerns me is when you said:
If you mean that you have brought all the circuits down into the sound booth in one conduit and all the switch legs return to the lights through another pipe there are two things I must ask.
1. are the neutrals for each circuit also running with each circuit conductor?
2. are the neutrals for each switch leg running to the lights ran in the same conduit or cable Assembly from the dimmers?
You should run the power feed to the lights separate from the power feed to the sound equipment. audio cables must be kept a good distance from the power feeds also. I do install professional sound and lighting systems and have been certified by Electro-Voice for about 15 years to do there installs. But it doesn't matter how much we know as there is always something different in each installation that takes experience to know how to solve a problem.
But I think I see other problems with this installation too
What kind of wires did you use for these circuit conductors?
You stated:
Are these electrical nonmetallic conduits ran all the way to the panel? Are they kept behind a 15 minute fire rated finish?
You made the statement:
I think this was a little wrong as I know God would wan't the job done right and done safely. I don't think God would wan't to jeopardize the lives of people who worships him. Maybe if you ask around you could get some help from a contractor. I know if you were in this area I would help. some contractors would do it if just for the advertisement.
I think you need to seek some hands on help where someone can see what you have and apply the right corrections.
Good luck
Re: Sound Board to Light Controls
Hurk27To answer your questions
1. What I did was from the end of the building where the circuits are I ran 3 each 3/4" emt feeds to 2 large 10 x 10 boxes. All power circuits run to 1 box then down thru pvc to my gutter switching area then into the 6 gang boxes via terminal strips to allow changeing around. Then the switched circuit returns back to a area where it picks up its neutral and terminates in a 1900 box. From there I tap in with 12/2 romex to the first light and then on to the next and so forth each run of emt has a seperate #12 thhn green in color its full length includeing all 1900 boxes there is bonding everywhere that I pre-put in to prevent feed back.
2. The neutrals run thru a seperate 3/4" piece of emt and the 1900 boxes they are in are right alongside the feed emts and the return legs . all circuits are numbered so they done get out of correct circuits.
All sound circuits are on seperate circuits used only for the sound board, the computer tie ins, the vcrs the cd players and the amplifiers. All wiring is done to 1999 code as that is what the local people use there call not mine.
This is a Article 550 type builing with 4 each 150 amp services run off a common underground feed from the main church 500 yards away with no problems existed for the past 10 years.It is a factory manufactured building.It is about 40 foot square with the speakers at the power end of the Church and the sound booth is at the other end of the church. As far as other contractors they dont want to be bothered but my partner is a contractor as well as I am for a very long time and we bonded everything in site as well as grounded everything in sight when we started out we removed over 400 feet of extension cords and now the building is up to code every where. Its just this sound thing is driveing us nuts.
The remark about God is right now I am fed up up to my ears with the dooms day crowd in our country. Nobody wants to do nothing for anybody else unless its there way or with enngineered drawings.
I think removeing the dimmers will probably fix the problem cause the system I built was working okay and I tried to get too fancy putting dimmers on lighting circuits..
Wayne understand nothing against anyone but when you donate time, material, energy and the churcj people speak nothing but nice its great. Then you ask for a little advice and the code book warriors come out with off the wall stuff it gets very very frustrateing.
Thanks for your input it is appreciated
Hurk27To answer your questions
1. What I did was from the end of the building where the circuits are I ran 3 each 3/4" emt feeds to 2 large 10 x 10 boxes. All power circuits run to 1 box then down thru pvc to my gutter switching area then into the 6 gang boxes via terminal strips to allow changeing around. Then the switched circuit returns back to a area where it picks up its neutral and terminates in a 1900 box. From there I tap in with 12/2 romex to the first light and then on to the next and so forth each run of emt has a seperate #12 thhn green in color its full length includeing all 1900 boxes there is bonding everywhere that I pre-put in to prevent feed back.
2. The neutrals run thru a seperate 3/4" piece of emt and the 1900 boxes they are in are right alongside the feed emts and the return legs . all circuits are numbered so they done get out of correct circuits.
All sound circuits are on seperate circuits used only for the sound board, the computer tie ins, the vcrs the cd players and the amplifiers. All wiring is done to 1999 code as that is what the local people use there call not mine.
This is a Article 550 type builing with 4 each 150 amp services run off a common underground feed from the main church 500 yards away with no problems existed for the past 10 years.It is a factory manufactured building.It is about 40 foot square with the speakers at the power end of the Church and the sound booth is at the other end of the church. As far as other contractors they dont want to be bothered but my partner is a contractor as well as I am for a very long time and we bonded everything in site as well as grounded everything in sight when we started out we removed over 400 feet of extension cords and now the building is up to code every where. Its just this sound thing is driveing us nuts.
The remark about God is right now I am fed up up to my ears with the dooms day crowd in our country. Nobody wants to do nothing for anybody else unless its there way or with enngineered drawings.
I think removeing the dimmers will probably fix the problem cause the system I built was working okay and I tried to get too fancy putting dimmers on lighting circuits..
Wayne understand nothing against anyone but when you donate time, material, energy and the churcj people speak nothing but nice its great. Then you ask for a little advice and the code book warriors come out with off the wall stuff it gets very very frustrateing.
Thanks for your input it is appreciated
hbiss
EC, New York NEC: 2017
- Location
- Little Falls, New York NEC: 2017
- Occupation
- EC
Re: Sound Board to Light Controls
This is a Article 550 type builing with 4 each 150 amp services
I'm going to have to disagree with you there. Looks like a place of assembly (Art 518) to me. It's the use, NOT how it was manufactured. And a 600A service for a 40x40' single story building should indicate something also.
I know you may be fed up with regulations and codes but what makes you think you should be any different? We have these things to hopefully keep you from seeing God before your time.
-Hal
This is a Article 550 type builing with 4 each 150 amp services
I'm going to have to disagree with you there. Looks like a place of assembly (Art 518) to me. It's the use, NOT how it was manufactured. And a 600A service for a 40x40' single story building should indicate something also.
I know you may be fed up with regulations and codes but what makes you think you should be any different? We have these things to hopefully keep you from seeing God before your time.
-Hal
- Location
- Illinois
- Occupation
- retired electrician
Re: Sound Board to Light Controls
Don
[ November 22, 2004, 01:21 PM: Message edited by: don_resqcapt19 ]
You can't do that. You must have both sides of the circuit in the same raceway. The hot must be run with either the neutral or the switch leg. The switch leg must be run with either the hot or the neutral.
Don
[ November 22, 2004, 01:21 PM: Message edited by: don_resqcapt19 ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Sound Board to Light Controls
Straps what Don has described is most likely where your problem lies as any time you run a supply circuit in a separate conduit from the return conductor you have set up a very large magnetic field around this conductor. When the supply is ran with the return conductor each will cancel out this field because each is 180 deg. out of phase from each other. This magnetic field will act just like a transmitter signal (carrier) from the lighting circuits to the audio circuits and will have the noise produced by the dimmers as the modulation which will be received via the audio wires and or the circuits powering the audio equipment. The problem is you can't filter 60hz as this is the frequency that the equipment runs on. so the only alternative is to make sure that each complete circuit is run in the same raceway. Like Don said if you have a hot to a switch then the return (switch leg) has to return in that same conduit to the point of connection to the circuit. If a hot is run to a light then the neutral has to return back to the source where the hot was suppled with power. The other problem is the PVC. If this PVC is not behind a 15 minute fire rated surface it is a violation of 518.4(C)(1) This is because PVC produces a very toxic smoke when burned and is very dangerous in the event of a fire. this smoke can render anyone who breaths it incapacitated, and not allow them to escape a fire. This is also why NM type wiring methods can not be used in these types of buildings. It wont matter what the AHJ allows as he is most likely protected by law against law suits and or prosecution which can happen and has across the country. There is a post on this site where an electrician was sent to prison for 5 years for involuntary manslaughter for killing a 12 year old boy. This is why you must stick with the safety of doing the work by code. You must rethink they way you handle electrical wiring as it can kill and if we are found guilty of not following code that led up to the death we can go to prison. And your talking about a whole building of people.
I do hope you think about this.
Straps what Don has described is most likely where your problem lies as any time you run a supply circuit in a separate conduit from the return conductor you have set up a very large magnetic field around this conductor. When the supply is ran with the return conductor each will cancel out this field because each is 180 deg. out of phase from each other. This magnetic field will act just like a transmitter signal (carrier) from the lighting circuits to the audio circuits and will have the noise produced by the dimmers as the modulation which will be received via the audio wires and or the circuits powering the audio equipment. The problem is you can't filter 60hz as this is the frequency that the equipment runs on. so the only alternative is to make sure that each complete circuit is run in the same raceway. Like Don said if you have a hot to a switch then the return (switch leg) has to return in that same conduit to the point of connection to the circuit. If a hot is run to a light then the neutral has to return back to the source where the hot was suppled with power. The other problem is the PVC. If this PVC is not behind a 15 minute fire rated surface it is a violation of 518.4(C)(1) This is because PVC produces a very toxic smoke when burned and is very dangerous in the event of a fire. this smoke can render anyone who breaths it incapacitated, and not allow them to escape a fire. This is also why NM type wiring methods can not be used in these types of buildings. It wont matter what the AHJ allows as he is most likely protected by law against law suits and or prosecution which can happen and has across the country. There is a post on this site where an electrician was sent to prison for 5 years for involuntary manslaughter for killing a 12 year old boy. This is why you must stick with the safety of doing the work by code. You must rethink they way you handle electrical wiring as it can kill and if we are found guilty of not following code that led up to the death we can go to prison. And your talking about a whole building of people.
I do hope you think about this.
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