so i learned a lesson today!

nathanvacha · 4th November 2007, 05:56 AM

so... just got home from a gig tonight (an early one, so i get to go see a show for fun still tonight) and we had... well, we had an interesting experience that i've actually never come across before. It was just a live sound gig, and i was contracted by a local sound company i work for pretty often.
it was a two day art festival with us and pretty much everything else there fed by a pretty decent sized catterpillar generator. we had plenty of power for the show, four 20A's covered it really, and about two hours before show time, as i was bringing power to the amps (just on iec's from their distro) i got a bit of a surprise...
so the power cable hits the dublex and i hear a 'pop!' and see a little waft of smoke. litt waft, but still... when it's comin' from an amp, smoke is smoke!
so the guy from the power company is insisting over the phone that it's not their kit and it had to be a bad amp, so the guy i'm working under has me try another amp on another circuit.... 'pop!' and a funny whirring sort of noise.

he finally gets there (as we're getting crap because the show is supposed to be on by then) and after checking everything for twenty minutes or so, lets us know that inside the plug of one of their sub-distro feeders, a hot and the neutral were crossed, so they had in fact sent us 208 down the line instead of 110.
this day i had not brought along my voltage meter (didn't bring much, supposed to be an easy show)
so the moral of the story (which turned out to be way longer than i meant it to...) is always check the power before you plug in.

pro · 4th November 2007, 06:53 AM

What would you have done if you did read the voltage at 208 prior ?

**Remoteness** · 4th November 2007, 09:04 AM

You experienced an interesting encounter that I bet you will never address the same way again.

I’ve been there and understand everything you encountered.

IMO, just because the person you work for is not forward thinking does mean you have to follow their path.

Upfront I want to say, "I’m sorry if I’m being too heavy, but you ARE dealing with live power that can do much more damage than blowing up sound equipment".

If you don't think I'm being heavy, please read on!

One thing you have to remember is people make mistakes.
Even professionals can be off their game.
I understand the concept of trusting your fellow teammates, but you must verify especially if you never dealt with that person.

I don’t understand why you folks never metered the feed from the generator?
Even if you didn't have a meter, you should have asked the power company to meter your feed.
With that said, I cannot believe the power company didn't meter the distro themselves.
This is so un-cool to say the least.
It's the first thing you should do before you power up your rig.

I designed ASL’s AC isolation transformers have meters and pilot lights before the main breakers so you can see if you’re energized and you have the correct voltage before you flip the breakers. We always meter, so I though why not install a permanent meter and such. Elroy has meters and pilot lights plus banana plug test points to make sure the meters are on point and if they fail we still have a way to easily check the voltage coming to our truck power panel.

Click on the two links to view a couple of pictures of our portable ISO XFMR.
The analog meter and pilot light is wired after the input Cam-Loks and before the main breaker.
http://www.gearslutz.com/board/attac...lexfmr2299.jpg
http://www.gearslutz.com/board/attac...lexfmr2309.jpg

IMO, whether or not you’re using your own equipment you must always meter the feed before you turn power on. It’s simply the only way to deal with power, especially when you’re not familiar with the company supplying it.

Metering the feed (before energizing) should have been the standard method of operation for the sound company you work for. I mean whether or not the guy from the power company is insisting it’s not their fault you should have metered the feed.
A sound company without a multi-meter in their tool box is not a real sound company.

I’m trying to find the logic in all this. I cannot believe the guy you work for asked you to try another amp on another circuit before testing the voltage. This is simply insane behavior to say the least.

Next time if you don’t have a meter try a light bulb before you consider using a power amp and a test set.

Next time consider running to Radio Shack or a hardware store and buy a meter or a light bulb -- it's much cheaper than two power amps.

In any even I still dig you because you walked away learning something very iimportant.

**Remoteness** · 4th November 2007, 09:12 AM

Quote:

Originally Posted by pro

What would you have done if you did read the voltage at 208 prior ?

I would have not blown up two power amps

I would have call the power company rep and said, I have 208v on my 120v line

I would have checked to see if the hot and neutral was reversed

Besides checking for the correct voltage you should also check for ground potential.
Checking the voltage between ground and neutral would have found the problem on the spot.

I hope this hepled.

Jim vanBergen · 4th November 2007, 02:06 PM

This is the kind of lesson I learned watching a mentor (who had a VERY bad day) in the late 80's, and I think it's SO GREAT to know that the next generation of people can learn this the easy way, not the hard way!

I carry one of the cheap-o Rat Shack analog VU power meters as well as the home depot three-led lights that confirms when your hot, neutral and ground are correctly wired. Those are on a three-way AC plug, it's the first thing plugged in at a new venue or new outlet! I can't control when my gear has a bad day (had a Hafler amp blow and took my Dynaudio monitors with it!) but I can control what I plug in, and if the house power is safe!

nathanvacha · 5th November 2007, 02:18 AM

yeah. i'm always used to using the same generator/distro usually when i work for this company, but it was different this time. there were already other people up and running, but must have been on a different feed... there were i think three different distro's going. but yeah, felt like a stupid mistake, but i'd never encountered that before. i'll check out those links you posted too, steve. thanks.

**Remoteness** · 5th November 2007, 02:38 AM

The items JvB mentioned are excellent (sound engineer) tool box stuffers.
Pretty standard items for our kind of work.

Maybe we should start a thread or add it to my (sticky) beginners thread about items for the ultimate sound & audio survival kit...

Maybe even take a few pictures and stuff.

If any one wants to start a thread I'll merge it into that sticky thread.

nathanvacha · 5th November 2007, 09:51 PM

that's a really good idea too, to start a sticky like that. i usually carry the voltmeter along when i'm doing a job with any real setup, and i've been meaning to pick up one of those light up outlet testers too. i guess that's motivation to make a trip to the hardware store.

Testing123 · 5th November 2007, 11:13 PM

If you get stuck without a meter you could find an incandescent lamp (60W, 100W, watt-ever) to plug in. It will either:

a) not light
b) light
c) pop like a flashbulb

-Keith

**Remoteness** · 5th November 2007, 11:29 PM

Quote:

Originally Posted by Testing123

If you get stuck without a meter you could find an incandescent lamp (60W, 100W, watt-ever) to plug in. It will either:

a) not light
b) light
c) pop like a flashbulb

-Keith

Great suggestion Keith, especially about popping like a flash bulb!

I did mention this in post #3...

I stated:

Quote:

Next time if you don’t have a meter try a light bulb before you consider using a power amp and a test set.

Next time consider running to Radio Shack or a hardware store and buy a meter or a light bulb -- it's much cheaper than two power amps.

Testing123 · 6th November 2007, 12:38 AM

Quote:

Originally Posted by Remoteness

I did mention this in post #3...

Sorry - read right past that...

**Remoteness** · 6th November 2007, 05:33 AM

Quote:

Originally Posted by Testing123

Sorry - read right past that...

No worries, I like the way you broke it down.

Well said and thanks for posting it!

Nick_1234 · 3rd January 2008, 09:00 PM

Steve.

I would be real interested in seeing how that "tool kit" thread evolves. Could you provide me with the link? Or should the search cover it?

Respect.

bove · 4th January 2008, 01:45 AM

I always use one of those Home Depot "3 LED" outlet testers before I plug in, and last week I found my first mis-wired outlet... not as exciting as exploding amplifiers, but I did avoid using a non-grounded outlet!

peeder · 4th January 2008, 01:53 AM

Don't most power conditioners have voltage readouts? Active before you switch on the power conditioner?

I use a three-LED thing too. Amazing how often incompetent electric is out there.

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4th November 2007, 05:56 AM	#1
nathanvacha Lives for gear Join Date: Dec 2005 Location: Orlando Posts: 1,191	so i learned a lesson today! so... just got home from a gig tonight (an early one, so i get to go see a show for fun still tonight) and we had... well, we had an interesting experience that i've actually never come across before. It was just a live sound gig, and i was contracted by a local sound company i work for pretty often. it was a two day art festival with us and pretty much everything else there fed by a pretty decent sized catterpillar generator. we had plenty of power for the show, four 20A's covered it really, and about two hours before show time, as i was bringing power to the amps (just on iec's from their distro) i got a bit of a surprise... so the power cable hits the dublex and i hear a 'pop!' and see a little waft of smoke. litt waft, but still... when it's comin' from an amp, smoke is smoke! so the guy from the power company is insisting over the phone that it's not their kit and it had to be a bad amp, so the guy i'm working under has me try another amp on another circuit.... 'pop!' and a funny whirring sort of noise. he finally gets there (as we're getting crap because the show is supposed to be on by then) and after checking everything for twenty minutes or so, lets us know that inside the plug of one of their sub-distro feeders, a hot and the neutral were crossed, so they had in fact sent us 208 down the line instead of 110. this day i had not brought along my voltage meter (didn't bring much, supposed to be an easy show) so the moral of the story (which turned out to be way longer than i meant it to...) is always check the power before you plug in.

5th November 2007, 02:38 AM	#7
Remoteness Super Moderator Join Date: Aug 2002 Location: NYC Posts: 4,919	The items JvB mentioned are excellent (sound engineer) tool box stuffers. Pretty standard items for our kind of work. Maybe we should start a thread or add it to my (sticky) beginners thread about items for the ultimate sound & audio survival kit... Maybe even take a few pictures and stuff. If any one wants to start a thread I'll merge it into that sticky thread. __________________ Steve Remote AuraSonicLtd.com the home of ASL Mobile & Location Production Remoteness on the Linkedin Network Remoteness on Myspace

3rd January 2008, 09:00 PM	#13
Nick_1234 Gear Head Join Date: Apr 2006 Location: Everett, WA Posts: 68	Steve. I would be real interested in seeing how that "tool kit" thread evolves. Could you provide me with the link? Or should the search cover it? Respect. __________________ "Whenever notes that are correct affect men, a corresponding good spirit responds to them; and when this good spirit accomplishes its manifestations, sublime music is the result." -Confucius "I only act like I don't give a make love." -Atmosphere "Dreams don't hurt people, dreamers do."

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4th November 2007, 06:53 AM	#2
pro Gear nut Join Date: Nov 2005 Posts: 148	What would you have done if you did read the voltage at 208 prior ?

4th November 2007, 09:04 AM	#3
Remoteness Super Moderator Join Date: Aug 2002 Location: NYC Posts: 4,919	Radio Shack has cheap meters for sale!!! You experienced an interesting encounter that I bet you will never address the same way again. I’ve been there and understand everything you encountered. IMO, just because the person you work for is not forward thinking does mean you have to follow their path. Upfront I want to say, "I’m sorry if I’m being too heavy, but you ARE dealing with live power that can do much more damage than blowing up sound equipment". If you don't think I'm being heavy, please read on! One thing you have to remember is people make mistakes. Even professionals can be off their game. I understand the concept of trusting your fellow teammates, but you must verify especially if you never dealt with that person. I don’t understand why you folks never metered the feed from the generator? Even if you didn't have a meter, you should have asked the power company to meter your feed. With that said, I cannot believe the power company didn't meter the distro themselves. This is so un-cool to say the least. It's the first thing you should do before you power up your rig. I designed ASL’s AC isolation transformers have meters and pilot lights before the main breakers so you can see if you’re energized and you have the correct voltage before you flip the breakers. We always meter, so I though why not install a permanent meter and such. Elroy has meters and pilot lights plus banana plug test points to make sure the meters are on point and if they fail we still have a way to easily check the voltage coming to our truck power panel. Click on the two links to view a couple of pictures of our portable ISO XFMR. The analog meter and pilot light is wired after the input Cam-Loks and before the main breaker. http://www.gearslutz.com/board/attac...lexfmr2299.jpg http://www.gearslutz.com/board/attac...lexfmr2309.jpg IMO, whether or not you’re using your own equipment you must always meter the feed before you turn power on. It’s simply the only way to deal with power, especially when you’re not familiar with the company supplying it. Metering the feed (before energizing) should have been the standard method of operation for the sound company you work for. I mean whether or not the guy from the power company is insisting it’s not their fault you should have metered the feed. A sound company without a multi-meter in their tool box is not a real sound company. I’m trying to find the logic in all this. I cannot believe the guy you work for asked you to try another amp on another circuit before testing the voltage. This is simply insane behavior to say the least. Next time if you don’t have a meter try a light bulb before you consider using a power amp and a test set. Next time consider running to Radio Shack or a hardware store and buy a meter or a light bulb -- it's much cheaper than two power amps. In any even I still dig you because you walked away learning something very iimportant. __________________ Steve Remote AuraSonicLtd.com the home of ASL Mobile & Location Production Remoteness on the Linkedin Network Remoteness on Myspace

4th November 2007, 02:06 PM	#5
Jim vanBergen Lives for gear Join Date: Apr 2005 Location: New York Friggin' City Posts: 2,296	This is the kind of lesson I learned watching a mentor (who had a VERY bad day) in the late 80's, and I think it's SO GREAT to know that the next generation of people can learn this the easy way, not the hard way! I carry one of the cheap-o Rat Shack analog VU power meters as well as the home depot three-led lights that confirms when your hot, neutral and ground are correctly wired. Those are on a three-way AC plug, it's the first thing plugged in at a new venue or new outlet! I can't control when my gear has a bad day (had a Hafler amp blow and took my Dynaudio monitors with it!) but I can control what I plug in, and if the house power is safe!

5th November 2007, 02:18 AM	#6
nathanvacha Lives for gear Join Date: Dec 2005 Location: Orlando Posts: 1,191	yeah. i'm always used to using the same generator/distro usually when i work for this company, but it was different this time. there were already other people up and running, but must have been on a different feed... there were i think three different distro's going. but yeah, felt like a stupid mistake, but i'd never encountered that before. i'll check out those links you posted too, steve. thanks.

5th November 2007, 09:51 PM	#8
nathanvacha Lives for gear Join Date: Dec 2005 Location: Orlando Posts: 1,191	that's a really good idea too, to start a sticky like that. i usually carry the voltmeter along when i'm doing a job with any real setup, and i've been meaning to pick up one of those light up outlet testers too. i guess that's motivation to make a trip to the hardware store.

5th November 2007, 11:13 PM	#9
Testing123 Gear Head Join Date: Nov 2007 Location: CT, USA Posts: 62	If you get stuck without a meter you could find an incandescent lamp (60W, 100W, watt-ever) to plug in. It will either: a) not light b) light c) pop like a flashbulb -Keith

4th January 2008, 01:45 AM	#14
bove Gear maniac Join Date: Dec 2005 Location: New York, NY Posts: 203	I always use one of those Home Depot "3 LED" outlet testers before I plug in, and last week I found my first mis-wired outlet... not as exciting as exploding amplifiers, but I did avoid using a non-grounded outlet!

4th January 2008, 01:53 AM	#15
peeder Lives for gear Join Date: Aug 2006 Location: No longer participating here. Posts: 6,742	Don't most power conditioners have voltage readouts? Active before you switch on the power conditioner? I use a three-LED thing too. Amazing how often incompetent electric is out there.