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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: Mike Sokol on June 18, 2014, 09:49:05 PM
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I'm not sure if I'm allowed to post this here, but my first eBook on RV Electrical Safety just published on Amazon/Kindle yesterday. What initially got me interested in starting No~Shock~Zone and researching vehicle grounding issues was a buddy of mine asking why he was getting shocked from a tour bus while plugged into shore power. It didn't take me long to realize that very little practical research had been done on this subject, so I dived in and started experimenting. See http://www.amazon.com/dp/B00L2DWBD8 for my first Kindle effort aimed at RV owners.
I'm now working on a second No~Shock~Zone eBook on electrical safety and shock/grounding issues for pro-sound venues and performers. Should be out by the end of the year and include everything I've been learning about ground loop and hum issues, plus other experiments I've been working on that affect sound quality in sound systems. Going to get even more interesting very soon.
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I'm not sure if I'm allowed to post this here, but my first eBook on RV Electrical Safety just published on Amazon/Kindle yesterday. What initially got me interested in starting No~Shock~Zone and researching vehicle grounding issues was a buddy of mine asking why he was getting shocked from a tour bus while plugged into shore power. It didn't take me long to realize that very little practical research had been done on this subject, so I dived in and started experimenting. See http://www.amazon.com/dp/B00L2DWBD8 for my first Kindle effort aimed at RV owners.
I'm now working on a second No~Shock~Zone eBook on electrical safety and shock/grounding issues for pro-sound venues and performers. Should be out by the end of the year and include everything I've been learning about ground loop and hum issues, plus other experiments I've been working on that affect sound quality in sound systems. Going to get even more interesting very soon.
You're a moderator, you can do anything. :D
But really, congrats on publishing!!
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Great book about tour buses and RVs. :-)
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If we buy the book, will you loan us a Kindle?
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I'm not sure if I'm allowed to post this here, but my first eBook on RV Electrical Safety just published on Amazon/Kindle yesterday. What initially got me interested in starting No~Shock~Zone and researching vehicle grounding issues was a buddy of mine asking why he was getting shocked from a tour bus while plugged into shore power. It didn't take me long to realize that very little practical research had been done on this subject, so I dived in and started experimenting. See http://www.amazon.com/dp/B00L2DWBD8 for my first Kindle effort aimed at RV owners.
Mike,
Excellent. Hopefully I'll get some bandwidth to read it. Is there any concern over PID damage of crystalline solar cells in the RV context, IOW how is the reference voltage plane handled for PV arrays in the RV/Bus context?
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If we buy the book, will you loan us a Kindle?
I doubt Mike would spring for that, but you try this: http://www.amazon.com/gp/feature.html?docId=1000493771
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If we buy the book, will you loan us a Kindle?
Kevin, you don't need a Kindle to read it. You can get a free Kindle Cloud reader from Amazon which works great. You can also download this it a Kindle app on your iPad which I've also tested and works well.
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I'm not sure if I'm allowed to post this here, but my first eBook on RV Electrical Safety just published on Amazon/Kindle yesterday. What initially got me interested in starting No~Shock~Zone and researching vehicle grounding issues was a buddy of mine asking why he was getting shocked from a tour bus while plugged into shore power. It didn't take me long to realize that very little practical research had been done on this subject, so I dived in and started experimenting. See http://www.amazon.com/dp/B00L2DWBD8 for my first Kindle effort aimed at RV owners.
I'm now working on a second No~Shock~Zone eBook on electrical safety and shock/grounding issues for pro-sound venues and performers. Should be out by the end of the year and include everything I've been learning about ground loop and hum issues, plus other experiments I've been working on that affect sound quality in sound systems. Going to get even more interesting very soon.
This would be very good for the industry. I have heard and seen some very questionable tour bus hookups in my time especially when the bus driver pulls out bare tails and says the white conductor is actually a hot leg. He definitely got some looks and questions on that. I bet that electrician did not want to burn a tour bus down.
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This would be very good for the industry. I have heard and seen some very questionable tour bus hookups in my time especially when the bus driver pulls out bare tails and says the white conductor is actually a hot leg. He definitely got some looks and questions on that. I bet that electrician did not want to burn a tour bus down.
I wonder if there's any Tour Bus organization or forums that would be interested? You're right, those buses are darn expensive. Burning up a guitar amp is one thing, but burning up the electrical system in a Prevost would be crazy expensive to fix.
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Don't forget the campgrounds and mobile home.
http://www.lakearrowheadcampground.com/
This is a family member that I have sent this link to for his work.
They may be starting to promote and review to ensure problems don't occur.
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I'm now beginning a review of the proposed 100-amp/240-volt hookups for RVs. The really scary thing is that retired folks will be hooking these things up. I'm not sure of the connector style yet, but I'll post here once I get more intel. As many of you know, the standard 50-amp RV and Tour Bus hookup in the US is a NEMA 14-50 (stove plug).
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I'm now beginning a review of the proposed 100-amp/240-volt hookups for RVs. The really scary thing is that retired folks will be hooking these things up. I'm not sure of the connector style yet, but I'll post here once I get more intel. As many of you know, the standard 50-amp RV and Tour Bus hookup in the US is a NEMA 14-50 (stove plug).
I have zero knowledge of this proposed standard except what you just wrote. But if I were dictator, I would specify an interlocking switch, whereby the receptacle cannot be energized until the plug is fully inserted, and the plug cannot be removed until the receptacle is de-energized by the interlocking switch. This would contain any arc flash to inside the switch body. But how can we expect such a switch to live long and prosper when just any old joe is flipping it on and off with a full RV load?
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I have zero knowledge of this proposed standard except what you just wrote. But if I were dictator, I would specify an interlocking switch, whereby the receptacle cannot be energized until the plug is fully inserted, and the plug cannot be removed until the receptacle is de-energized by the interlocking switch. This would contain any arc flash to inside the switch body. But how can we expect such a switch to live long and prosper when just any old joe is flipping it on and off with a full RV load?
I'm getting proposed code updates from a few RVIA members who are on an NEC subcommittee discussing the future of RV power. And yes, I'm with you that any connector for this application needs to have a dead-panel interlocking switch of some kind. But these committees are largely populated with manufacturer reps who are most interested in getting their own products on the code list. So we all know how that goes.... profit before logic sometimes.
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Camlocks. All the same colour. All reverse polarity.
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Camlocks. All the same colour. All reverse polarity.
Love it.... What are the odds of a correct hookup with four identical camlocks? Is it 1 in 16 (4 bits) or what? ;D
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Love it.... What are the odds of a correct hookup with four identical camlocks? Is it 1 in 16 (4 bits) or what? ;D
1:4! (that's mathematical notation for '4 factorial' -- 4*3*2*1=24) -- one in 24.
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IMO when working with the larger diesel generator I find that they come with a twist lock connector.
I would prefer a twist lock to help prevent people from pulling out when they trip in the power cord.
This would prevent the arc and flash hazard of the disconnect under power and prevent the exposed blades being available to fall upon.
Room for a new and larger Power con connector ? Now exposed touchable contacts ??
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1:4! (that's mathematical notation for '4 factorial' -- 4*3*2*1=24) -- one in 24.
I LOVE this forum...
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I'm now beginning a review of the proposed 100-amp/240-volt hookups for RVs. The really scary thing is that retired folks will be hooking these things up. I'm not sure of the connector style yet, but I'll post here once I get more intel. As many of you know, the standard 50-amp RV and Tour Bus hookup in the US is a NEMA 14-50 (stove plug).
Hasn't this already been hashed out in the marine industry?
My bet is that people are attempting to cheap out. It has been quite a while since I worked on big boats but I seem to remember a shore cable being in the $2500-$3000 range.
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Hasn't this already been hashed out in the marine industry?
They are talking about marine connectors for this, but other than that I'm still in the dark. This is pretty early inner sanctum stuff, so I'll have to keep sniffing around until I get some solid info. But the scuttlebutt is that it's definitely coming.
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A 100 amp plug/receptacle-especially one interlocked to prevent disconnecting under load won't be cheap. But my guess is that if you can afford an RV that needs a 100 amp service (especially given all the new low power LED stuff) you can probably afford the right plug/receptacle combo.
BTW-twistlocks will prevent unintentional disconnects under load-but they won't stop stupid disconnects under load.
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A 100 amp plug/receptacle-especially one interlocked to prevent disconnecting under load won't be cheap. But my guess is that if you can afford an RV that needs a 100 amp service (especially given all the new low power LED stuff) you can probably afford the right plug/receptacle combo.
BTW-twistlocks will prevent unintentional disconnects under load-but they won't stop stupid disconnects under load.
Mike has mentioned this before, I think, but I'll say this - some the cheapest, most clueless bastards on earth are driving Class A motor homes. "Can you make that noise stop?" "Which noise?" "That incessant beeping." "Uh... that's your propane leak detector. Excuse me while I move back 300 feet."
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A 100 amp plug/receptacle-especially one interlocked to prevent disconnecting under load won't be cheap. But my guess is that if you can afford an RV that needs a 100 amp service (especially given all the new low power LED stuff) you can probably afford the right plug/receptacle combo.
Remember, some of these people will slap down another $10,000 for a better grade of granite in their kitchens without batting an eye, but will whine about paying an extra $200 for spec-grade receptacles throughout the house instead of the 59 cent backstabs.
When it comes to electrical stuff, there is a perception that if they are allowed to sell it, then it's safe, so there's no difference between one item and another that costs three times as much. What they don't realize is that it's not safe when used outside of it's intended application and duty cycle. A 100A cord and plug connection may be safe for a welder where it's almost certain that it won't be under load when connected/disconnected, but not necessarily for an RV where there is no guarantee that the load will be removed first.
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1:4! (that's mathematical notation for '4 factorial' -- 4*3*2*1=24) -- one in 24.
Whoops, that should be one in 12 (2 in 24), since the two line poles can be safely interchanged (assuming 120/240V single phase service).
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Mike has mentioned this before, I think, but I'll say this - some the cheapest, most clueless bastards on earth are driving Class A motor homes. "Can you make that noise stop?" "Which noise?" "That incessant beeping." "Uh... that's your propane leak detector. Excuse me while I move back 300 feet."
Tim is right. I see a lot of $100K to $250K motor homes hooked up with a too-small orange extension cord from Home Depot. Or they'll be working on them while powered up with an ungrounded drop light. That's what killed one RV owner in this own front yard. I always advocate that RV owners use the best grade and heaviest power cables available, and never use a damaged cord. The exact same thing goes for sound system operators. A cheap and/or broken power cord can damage your gear and get you killed.
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Tim is right. I see a lot of $100K to $250K motor homes hooked up with a too-small orange extension cord from Home Depot. Or they'll be working on them while powered up with an ungrounded drop light. That's what killed one RV owner in this own front yard. I always advocate that RV owners use the best grade and heaviest power cables available, and never use a damaged cord. The exact same thing goes for sound system operators. A cheap and/or broken power cord can damage your gear and get you killed.
Only $100k? The clueless asshole with the propane leak was in a $700k+ Marathon conversion on a Prevost chassis. The story is true. His propane leak was in the "tailgate" bay with the BBQ grill. I met him because his 3 wire plug wouldn't mate with the NEMA 14-50 outlet provided on the power stand. His plug had the neutral and EGC double-lugged to the middle pin... He wanted me to disconnect "whatever is making that noise" when I was called to replace the cordset plug.
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Whoops, that should be one in 12 (2 in 24), since the two line poles can be safely interchanged (assuming 120/240V single phase service).
Why do I get so alert/nervous whenever I hear a sparky say "whoops"? :o Mark C.
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Only $100k?
I once was in a McDonalds getting a little breakfast when some old guy at the counter was ranting and raving that they wanted to charge him $1.39 for coffee when they advertized one-dollar coffee on the door. He stormed out without his coffee, then walked to his Prevost Motorhome pissing and moaning the whole way. I know they start at around half a million bucks, and he was mad about an extra 39 cents.
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Whoops, that should be one in 12 (2 in 24), since the two line poles can be safely interchanged (assuming 120/240V single phase service).
Why do I get so alert/nervous whenever I hear a sparky say "whoops"? :o Mark C.
Just to set the record straight, I am not a sparky. I just have a deep interest in electrical wiring AND in doing it correctly and safely. My dream job always was to be an electrician, but those stars never aligned. I can actually wire 3-way light switches without a diagram and have them work correctly the first try.
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Just to set the record straight, I am not a sparky. I just have a deep interest in electrical wiring AND in doing it correctly and safely. My dream job always was to be an electrician, but those stars never aligned. I can actually wire 3-way light switches without a diagram and have them work correctly the first try.
http://www.electrical-online.com/3wayswitch/
What is wong with their picture (aside from assuming you only use 15 amp circuits for lights)?
At least they didn't show other variations that could result in 2 hots on the socket.
Jeff Robinson
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As shown the light would be off. Flip one switch. Or reverse the travelers at one end.
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What is wong with their picture (aside from assuming you only use 15 amp circuits for lights)?
Well, for one thing, 3-way switches aren't marked "ON" (or "OFF" for that matter). And the wires don't actually make contact with the bulb, (which doesn't meet federal standards for efficiency) so it's glowing by some mysterious electrical force.
And if you really want to get picky, they don't show the EGC which should be bonded to the yoke of each switch, and connections and devices are not contained within boxes! But I must assume that the artist assumed that people would assume that those things are necessary and removed them from the drawing to avoid unnecessary complication.
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As shown the light would be off. Flip one switch. Or reverse the travelers at one end.
I like to wire them so when all switches are down the light is off. (Not sure what this has to do with tour buses, seems the topic veered.)
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I like to wire them so when all switches are down the light is off. (Not sure what this has to do with tour buses, seems the topic veered.)
+1. Unfortunately, that also means when all switches are UP, the light is also off.
Sometimes, you just can't win.
Tour Buses.... I worked with a group once, there were 3-way switches for the "common area" lights in the Prevost.
There ya go, back on topic (sorta)
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And surely there have been all kinda of 3-ways, not just switches, on tour buses....
Sent from my iPhone using Tapatalk
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Unfortunately, that also means when all switches are UP, the light is also off.
Sometimes, you just can't win.
If you add a 4-way switch and wire the three switches so that all down is off, the light will be on if they are all up.
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Back OT
If you want to see my new video series about RV power here's me debunking the myth that rubber tires on an RV or Tour Bus have nothing to do with protecting you from lightning: http://www.youtube.com/watch?v=abLUcHZx6OU&list=UUARpsGWj6MJ7JE78OcfWKWw (http://www.youtube.com/watch?v=abLUcHZx6OU&list=UUARpsGWj6MJ7JE78OcfWKWw)
And here's where I discuss why it's a good idea to unplug shore power from an RV while in a lightning storm. http://www.youtube.com/watch?v=ZBv7TCkea4A&index=4&list=UUARpsGWj6MJ7JE78OcfWKWw (http://www.youtube.com/watch?v=ZBv7TCkea4A&index=4&list=UUARpsGWj6MJ7JE78OcfWKWw)
Of course, I think that most (or all) of you should know this already. But RV owners often think their expensive Class-A Motorhomes somehow exempt them from the laws of physics.
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+1. Unfortunately, that also means when all switches are UP, the light is also off.
That works for me too. Light on when the switches differ.
Steve.