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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => AC Power and Grounding => Topic started by: Tommy Peel on October 29, 2013, 11:34:51 pm

Title: Busted power strip....
Post by: Tommy Peel on October 29, 2013, 11:34:51 pm
Found this when I was setting up the PA for our Tuesday Night youth church service(we have to setup and tear down our rig every week). One of the band members had the thing hooked up with a couple of instrument amps plugged into it before I noticed..... :O

 (http://img.tapatalk.com/d/13/10/30/8aru9e4u.jpg)

Needless to say it's deep in the trash now.

Sent from my Nexus 4 using Tapatalk

Title: Re: Busted power strip....
Post by: Barry Singleton on October 29, 2013, 11:43:53 pm
On the bright side, at least it's the neutral side.
Title: Re: Busted power strip....
Post by: Kevin Graf on October 30, 2013, 10:37:37 am
"One of the band members"
Let me guess:  it was the bass player?
Title: Re: Busted power strip....
Post by: Tommy Peel on October 30, 2013, 12:43:52 pm
"One of the band members"
Let me guess:  it was the bass player?
Well he wasn't playing bass last night, but he does on occasion(along with electric guitar, drums, keys, and banjo). The bass amp was one of the things plugged into it when  I found it though. ;D

Sent from my Nexus 4 using Tapatalk

Title: Re: Busted power strip....
Post by: Jordan Wolf on October 30, 2013, 12:55:52 pm
Found this when I was setting up the PA for our Tuesday Night youth church service...
Ooh...what an appropriate thread!

 We found this at our corporate event just a few days ago.  Apparently someone doing overnight cleaning had an issue - the strip was still plugged in and the "ON" light glowing when we found it.  Oh, and the HOT pin was still stuck in the slot that had arced...

Needless to say, I cut the cord off of it and brought it home so I know it won't be used again.



Title: Re: Busted power strip....
Post by: Mike Sokol on October 30, 2013, 03:12:19 pm
Ooh...what an appropriate thread!

 We found this at our corporate event just a few days ago.  Apparently someone doing overnight cleaning had an issue - the strip was still plugged in and the "ON" light glowing when we found it.  Oh, and the HOT pin was still stuck in the slot that had arced...

Needless to say, I cut the cord off of it and brought it home so I know it won't be used again.

I've got one laying around in the junk bin somewhere that looks very similar. And I cut the cord off as well to prevent "emergency use". I think that space heaters are some of the worst offenders since they can easily draw 12 amps or so for a 1,500 watt heater, and that's a lot of receptacle contact heating going on for long periods of time. My local fire company chief (who happens to be the first drummer I ever played with in a band when I was 15 years old) told me they always get a bunch of electrical fires the first few cold nights of the season when the space heaters get plugged into power strips. 
Title: Re: Busted power strip....
Post by: RYAN LOUDMUSIC JENKINS on October 31, 2013, 08:33:45 am
Ooh...what an appropriate thread!

 We found this at our corporate event just a few days ago.  Apparently someone doing overnight cleaning had an issue - the strip was still plugged in and the "ON" light glowing when we found it.  Oh, and the HOT pin was still stuck in the slot that had arced...

Needless to say, I cut the cord off of it and brought it home so I know it won't be used again.

Corporate gig?    So they charged you $29.00 per day to rent the slower strip and then $179.00 to replace it since it got damaged, right?
Title: Re: Busted power strip....
Post by: Jordan Wolf on October 31, 2013, 10:44:29 pm
Corporate gig?    So they charged you $29.00 per day to rent the slower strip and then $179.00 to replace it since it got damaged, right?
At some places, maybe that would be the case, but...we're the in-house AV company here.  The hotel charges for power distro - tie-ins, tails, and distro boxes; we have our own dimmers and distros that we use for shows that use us instead of bringing in outside production.

That being said, we weren't using the power strip in any capacity (or ampacity), we just found it like that in the morning and decided to make the situation "safe".  If it came down to it, I'd pay that $179 for a new strip if it meant possibly saving someone's life - that's a small price to pay.
Title: Re: Busted power strip....
Post by: Jonathan Johnson on November 02, 2013, 04:07:30 pm
Needless to say, I cut the cord off of it and brought it home so I know it won't be used again.

Any time I discard a failed cord (whether power, audio, network, or anything else) I ALWAYS cut the ends off. Otherwise, someone WILL fish it out of the trash and try to reuse it.
Title: Re: Busted power strip....
Post by: Jordan Wolf on November 02, 2013, 06:54:54 pm
Any time I discard a failed cord (whether power, audio, network, or anything else) I ALWAYS cut the ends off. Otherwise, someone WILL fish it out of the trash and try to reuse it.
I have learned to never underestimate the power of stupidity.  It's a shame...and just one more thing we have to worry about and consider.
Title: Re: Busted power strip....
Post by: Greg_Cameron on November 08, 2013, 12:52:06 pm
One topic to maybe add to this forum for discussion would be so-called "surge protector" power strips. My understanding is that with the cheapies, the MOVs don't last long and can start leaking current into the neutral and ground buses which can cause noise and other problems. I also recall years ago reading that you're not supposed to daisy chain surge strips off of each other or off of UPSs. I make it a point to never do that and if I need more outlets split off of a UPS or another surge strip, I use "power tap" labeled power strips which means they don't contain MOVs or other components.  Any input on that topic Mike?
Title: Re: Busted power strip....
Post by: Mike Sokol on November 08, 2013, 02:11:00 pm
One topic to maybe add to this forum for discussion would be so-called "surge protector" power strips. My understanding is that with the cheapies, the MOVs don't last long and can start leaking current into the neutral and ground buses which can cause noise and other problems. I also recall years ago reading that you're not supposed to daisy chain surge strips off of each other or off of UPSs. I make it a point to never do that and if I need more outlets split off of a UPS or another surge strip, I use "power tap" labeled power strips which means they don't contain MOVs or other components.  Any input on that topic Mike?
I do know that standard MOV surge strips can leak up to 3 mA between hot and ground. So adding two MOV surge strips on a single GFCI circuit can easily cause it to nuisance trip at the 5mA threshold. Also, as you indicate, a MOV is a sacrificial element that will eventually "wear out" from absorbing multiple voltage spikes. The bad thing is that you really don't know if the MOV is still working or not. Some of the high-end surge protectors (not sure if they're MOV based) have an indicator light to tell you if the surge protector is still working. Not sure how they generate the signal for the indicator light, but that would be an interesting thing to know. I'll call a few of my EE buddies to see if any of them have a handle on it. I think that's a great idea for a topic.
Title: Re: Busted power strip....
Post by: Greg_Cameron on November 08, 2013, 04:21:45 pm
Years ago, I had two racks at FOH, both with Furman "power conditioner" rack units. I had one rack's Furman plugged into the other. I had my Mac laptop sitting on the one Rack that was chained to the other. When I rested my hand on the metal rack edge and touched my laptop, I got a mild but noticeable tingle on my fingers. I reconfigured my power so that that both racks were plugged into the quad box stringer coming from my main distro rather than a daisy chain and the issue subsided. I suspect there were some leaking MOVs causing noticeable ground voltage differential between the quad box and racks. Daisy chaining Furmans probably exacerbated the issue. I never do it anymore.