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Author Topic: Can Repeated Distro Trips Harm Audio Gear?  (Read 1177 times)

frank kayser

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #10 on: July 01, 2014, 02:55:57 pm »

... 3-4 times a year really probally means the generator isn't being run enough, they need to be run once a month in my opinion to keep the coils good. they also need a lot of up keep & maintenance.


I don't know about keeping the "coils" good - I'm not sure permanent magnets are part of a current "generator" design. 


But most engines don't really like to sit - condensation in the oil and fuel, battery maintenance, seals dry out, belts, hoses. 


FWIW...
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Ray Aberle

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #11 on: July 01, 2014, 02:57:55 pm »

You might call it BS but generators can lose their magnetivity and will properly generate power.

And this statement is confuddling, soooo...

Either way, everyone will have a different POV as to owning versus renting. As Tim Mc would say, Excess Capacity Is Infinitely Expensive.

But, the promoters have already purchased it, so discussing whether that's a good idea or not is futile. The decision was already made. So let's help Mike be a better resource for the people who hired him, and not question the wisdom of buying a generator! As long as it works reliably... And Mike always meters his power before connecting his gear to it. :)

-Ray
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Mike Sokol

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #12 on: July 01, 2014, 03:55:51 pm »

You might call it BS but generators can lose their magnetivity and will not properly generate power.

I think I know the answer to this, but can someone please reference re-flashing a generator? I don't think it's a big deal to do at all, and is generatlly only needed if the generator was disassembled or sat inoperative for a decade. But maybe I'm wrong.

However, gas engines need to have their fuel system drained for extended storage, and having a shutoff valve on the carb is an easy way to burn off the excess fuel at the end of every gig. That's what I do with my lawn-mower and house genny, and it works great. I throw in some Sta-Bil fuel additive if it won't be run for more than a month, burn-off the fuel out of the carb if I won't be running it the next day, and call it done. Or am I making this too simple? 

frank kayser

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #13 on: July 02, 2014, 07:20:57 pm »


However, gas engines need to have their fuel system drained for extended storage, and having a shutoff valve on the carb is an easy way to burn off the excess fuel at the end of every gig. That's what I do with my lawn-mower and house genny, and it works great. I throw in some Sta-Bil fuel additive if it won't be run for more than a month, burn-off the fuel out of the carb if I won't be running it the next day, and call it done. Or am I making this too simple?
I can reference only what multiple sources (oil distributor, motorcycle shop, riders) that when putting a motorcycle away for the winter, fuel should be drained, and run out (tank should be able to evaporate any condensation that will form) oil should be changed to get rid of any acids and other combustion byproducts from the oil, and battery put on a battery tender.  Taking it out of storage, oil should be changed AGAIN, as condensation during the winter months will have formed in the crankcase and contaminated the oil.  Fresh fuel, check running gear and fire it up.


I don't do that.  I don't buy into the oil change every 3K miles - owners manual doesn't require that.  Oil gets changed with tire changes (between 8K and 12K miles) fuel gets Stabil if it will sit more than a week (methanol in the fuel evaporates/breaks down very quickly), and try to park it with nearly a full fuel tank (my tank is plastic so condensation is less of an issue).  Same with the lawn mower (though the lube system on the engine is more primitive, and the tires that never wear out)


Seals will dry out when an engine is not used, and rust can form (in extreme cases seizing the engine) especially if exhaust or intake are subject to water penetration.  Hoses, belts, and other rubber parts will deteriorate at about the same rate whether the engine has been
run or not. 


Diesels are particularly sensitive to water in the fuel - diesel injectors / mechanical injector pumps operate at extreme pressures, and need ultra-tight tolerances to build that type of pressure.  What appears to be minor pitting in the surfaces result in non-operational or poorly operating injectors.  Watch for condensation, and service the fuel/water separator religiously.


Don't forget belts.  Our very big quasi-government business had an entire COOP (Continuity of Operations) drill ruined as the generator for the main management/IT site threw a belt in the first 10 minutes of the drill.  No com.  No computers. 


frank 

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Steve M Smith

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #14 on: July 03, 2014, 02:44:00 am »

Taking it out of storage, oil should be changed AGAIN, as condensation during the winter months will have formed in the crankcase and contaminated the oil.

If it's sitting in a garage and its temperature is matching the ambient temperature in the garage, there will be no condensation.


Steve.
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Steve Alves

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #15 on: July 03, 2014, 09:58:14 am »

The first problem seemed to be with the small (1.5 VA) APC UPS unit that was inline before the DR260 system processors and the FOH digital board.  Neither of those devices pulled much current so the UPS was in no way overloaded.  Yet that UPS would squeal with an alarm frequently which was sometimes followed by a shutdown of the UPS.  I am not sure what the alarm meant as it was a continuous squeal and historically the only alarm I have hear from it is the beeping sound it makes when mains power is not present and the battery is engaged.  After a couple of shutdowns that alarm noise became apparent and the battery backup was removed from the circuit.

Caused by the power going in not being clean and the UPS having to repeatedly switch to battery. Could have been caused by the same problem that was tripping the GFCI's or just voltage sag.
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Tim McCulloch

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #16 on: July 03, 2014, 10:42:27 am »

I was a subcontractor on a gig this weekend using  an undersized generator (Whisperwatt 25) and we had repeated losses of power for a variety of reasons.


First due to lack of timely delivery of the 6/4 feeder and spider box, we were running FOH, monitors, and backline off the two 20A convenience GFCI outlets.  Power was delivered through three 100 foot 12/3 SOOW cables.


The first problem seemed to be with the small (1.5 VA) APC UPS unit that was inline before the DR260 system processors and the FOH digital board.  Neither of those devices pulled much current so the UPS was in no way overloaded.  Yet that UPS would squeal with an alarm frequently which was sometimes followed by a shutdown of the UPS.  I am not sure what the alarm meant as it was a continuous squeal and historically the only alarm I have hear from it is the beeping sound it makes when mains power is not present and the battery is engaged.  After a couple of shutdowns that alarm noise became apparent and the battery backup was removed from the circuit.


Then it seemed there was just too much current draw for the GFCI outlets.  The breakers did not trip but the GFCI's did.  After three or four of those episodes the GFCI's seemed to be "fried" as they would no longer reset. 

Mike, if the GFCI were tripping there was an actual or perceived current leakage...  A GFCI will not trip due to over-current.  WILL.  NOT.  TRIP.  You had a bad device (maybe the MOVs in the surge-only side of the UPS) or cord somewhere.  On another site I have a blog post about a gig where the generator provider had to work on the sound genny and we had to fly the PA using power from the lighting genny.  The lighting guys were using the courtesy outlets to set DMX addresses and it didn't occur to me to meter the voltage.  Our 1 ton hoists are 120v single phase, so I took power from the same outlet the lighting guys had used.  Stage left went up without a problem, but stage right kept tripping the GFCI.  My boss was there and metered power, was convinced that the 150v he found was the problem (the lighting guys never metered, we found out).  I set the voltage back to 120v but the GFCI kept tripping.  Eventually the hoist stopped working, we got the fork lift to take the PA down and replaced the hoist.  The replacement worked flawlessly.  Upon inspection we determined that the failed hoist had a 1 strand hot wire short to the motor housing (the strain relief wasn't preventing twisting).  The GFCI was, in fact, doing its job correctly.  It would have been possible to energize the entire Apex mobile stage (like a Stageline) via the hoist chain.

NEVER simply assume that a GFCI is defective (although it might be), and never assume they trip due to load - they don't.

Quote
Fortunately about this time the feeder cable and spider box arrived but unfortunately it was a pretty beat up spider box and only 3 of the GFCI outlets actually worked.  When they tried to runs some lights as well (old parr cans)  there were tripping issues that seemed to involve GFCI trips rather than breaker trips.

Again, I'd assert that there was actual current leakage.  Old PAR cans?  Yeah, we find all kinds of dodgy stuff that comes from not keeping up on maintenance.

Quote
Anyway it goes on for a bit but the upshot is that the amps, processors, mixer, and powered monitors were subjected to numerous power resets.  I am wondering if that can be damaging to this equipment?

No.
« Last Edit: July 03, 2014, 12:29:43 pm by Tim McCulloch »
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Mike Sokol

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #17 on: July 03, 2014, 12:09:38 pm »

Mike, if the GFCI were tripping there was an actual ground fault.  A GFCI will not trip due to over-current.  WILL.  NOT.  TRIP. 

Tim, the rest of your explanation is spot-on, but your above statement is a bit misleading. I've done this experiment a bunch of times on my lab bench to get my head wrapped around GFCI tripping mechanisms. If you double-bond the neutral and ground wires together at both ends of the branch circuit, keeping the GFCI within that loop, then the neutral return current will be split between the ground AND neutral wires. Since a GFCI is looking for the same amount of current on the neutral and line wires, it will then trip with most any small load. So it's not only a hot-to-ground fault that will cause a GFCI to trip, but also a neutral-to-ground fault.  But yes, you are correct that a GFCI receptacle is NOT an over-current device, though a GFCI panel mounted circuit breaker certainly is. 

One thing that I've found that if the GFCI won't reset at all with no appliance/tool plugged into it, then the GFCI is likely at fault. If it holds with no appliance/tool plugged in but trips when the appliance/tool is plugged in, then it's likely there a hot-to-chassis/ground fault. However, if it holds with no appliance/tool plugged in, holds with the tool  plugged in but not turned on, but then trips when the appliance/tool is turned on and presents any kind of load to the circuit, then it's possible there could be a neutral-to-ground fault somewhere. Of course, your mileage will vary, but this is at least a starting point for GFCI troubleshooting which can be a real PITA at times.

Interesting stuff, isn't it?  ;D

Tim McCulloch

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #18 on: July 03, 2014, 12:30:08 pm »

Tim, the rest of your explanation is spot-on, but your above statement is a bit misleading. I've done this experiment a bunch of times on my lab bench to get my head wrapped around GFCI tripping mechanisms. If you double-bond the neutral and ground wires together at both ends of the branch circuit, keeping the GFCI within that loop, then the neutral return current will be split between the ground AND neutral wires. Since a GFCI is looking for the same amount of current on the neutral and line wires, it will then trip with most any small load. So it's not only a hot-to-ground fault that will cause a GFCI to trip, but also a neutral-to-ground fault.  But yes, you are correct that a GFCI receptacle is NOT an over-current device, though a GFCI panel mounted circuit breaker certainly is. 

One thing that I've found that if the GFCI won't reset at all with no appliance/tool plugged into it, then the GFCI is likely at fault. If it holds with no appliance/tool plugged in but trips when the appliance/tool is plugged in, then it's likely there a hot-to-chassis/ground fault. However, if it holds with no appliance/tool plugged in, holds with the tool  plugged in but not turned on, but then trips when the appliance/tool is turned on and presents any kind of load to the circuit, then it's possible there could be a neutral-to-ground fault somewhere. Of course, your mileage will vary, but this is at least a starting point for GFCI troubleshooting which can be a real PITA at times.

Interesting stuff, isn't it?  ;D

Fixed it to read "...actual or perceived current leakage."
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Mike Sokol

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Re: Can Repeated Distro Trips Harm Audio Gear?
« Reply #19 on: July 03, 2014, 12:42:45 pm »

Fixed it to read "...actual or perceived current leakage."

Perfect.... I hate to pick nits sometimes, but this stuff is tricky.

Mike
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