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Author Topic: Another bonding question  (Read 500 times)

Mark Cadwallader

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Another bonding question
« on: October 17, 2020, 04:04:06 am »

I'm trying to perform my due diligence while thinking (daydreaming?) about buying portable stage decks.  I'm considering the Wenger StageTek aluminum framed deck units, although there are a number of similar items from other companies.  There is a four inch (100 mm) aluminum extrusion that runs the perimeter of the individual deck units. There is probably some aluminum to aluminum contact between the individual deck units, but there is no hard mechanical connection (as would be the case with a coffin lock) deck to deck once the stage is assembled.

Assuming that I have set up the stage on the grass in a park, is it prudent that I modify the stage decks to run a stranded copper wire jumper (like 12 AWG) that connects a deck to an adjacent deck, so that all of the decks are bonded to one another, and then run a heavier wire (like 6 AWG) to bond to whatever electrical service I'm using?  I've read a couple of prior threads on the topic that seem to suggest that one should, but there has not been an explicit discussion saying it is appropriate to actually connect wire jumpers deck to deck.  Setting up a portable stage indoors I've never seen it done (or suggested), but outdoors seems like it might be a different situation to consider.  Am I over-thinking this, and just adding unnecessary work to my setup and strike?  I note that StageLine trailers have a specific lug to "ground" the trailer.

Along the same line of thought, how specifically do I go about actually making the bonding connection to the electrical service?  A common scenario is that there is 50 amp 240 volt service (via a NEMA 14-50 outlet) that I'm connecting to my distro. To what do I attach my 6 AWG stage bonding wire?  The service is run to a free-standing pedestal for plug and play connections.  I assume that a licensed electrician will not be standing by help me.

I can leave the issue of what to do if I'm using a small generator (under 5000 watts rated power) instead of plugging into the grid for another day.

I look forward to hearing the collective wisdom from the forum.  Even if I don't move forward with my idea, it is still probably worth my thinking about.

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Scott Holtzman

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Re: Another bonding question
« Reply #1 on: October 17, 2020, 06:40:06 pm »

I'm trying to perform my due diligence while thinking (daydreaming?) about buying portable stage decks.  I'm considering the Wenger StageTek aluminum framed deck units, although there are a number of similar items from other companies.  There is a four inch (100 mm) aluminum extrusion that runs the perimeter of the individual deck units. There is probably some aluminum to aluminum contact between the individual deck units, but there is no hard mechanical connection (as would be the case with a coffin lock) deck to deck once the stage is assembled.

Assuming that I have set up the stage on the grass in a park, is it prudent that I modify the stage decks to run a stranded copper wire jumper (like 12 AWG) that connects a deck to an adjacent deck, so that all of the decks are bonded to one another, and then run a heavier wire (like 6 AWG) to bond to whatever electrical service I'm using?  I've read a couple of prior threads on the topic that seem to suggest that one should, but there has not been an explicit discussion saying it is appropriate to actually connect wire jumpers deck to deck.  Setting up a portable stage indoors I've never seen it done (or suggested), but outdoors seems like it might be a different situation to consider.  Am I over-thinking this, and just adding unnecessary work to my setup and strike?  I note that StageLine trailers have a specific lug to "ground" the trailer.

Along the same line of thought, how specifically do I go about actually making the bonding connection to the electrical service?  A common scenario is that there is 50 amp 240 volt service (via a NEMA 14-50 outlet) that I'm connecting to my distro. To what do I attach my 6 AWG stage bonding wire?  The service is run to a free-standing pedestal for plug and play connections.  I assume that a licensed electrician will not be standing by help me.

I can leave the issue of what to do if I'm using a small generator (under 5000 watts rated power) instead of plugging into the grid for another day.

I look forward to hearing the collective wisdom from the forum.  Even if I don't move forward with my idea, it is still probably worth my thinking about.


Mark I would highly recommend getting Stageright decks.  It's what everyone wants and will open up cross renting opportunities like you can't believe.  We had Wegner deck for several years and even in this downturn the Stageright is still making money.  With Stageright the locator pins provide grounding between the deck frames. 

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Scott AKA "Skyking" Holtzman

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Mark Cadwallader

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Re: Another bonding question
« Reply #2 on: October 17, 2020, 08:57:09 pm »

Scott, thank you for your reply. I have only read the on-line material about the StageRight decks. IIRC, they are designed to "share" supports with adjacent decks, via non-metal locator pins attached to the base structure.  Does the construction or spacing of the locator pins force a mechanical (electrically bonded) connection between adjacent decks?

It looks to me that the StageRight decks are designed to be used in groups of three (two base units, with one deck spanning the gap between bases). Unless I've missed something (quite possible due to having 4 broken ribs and the pain from that), having a two-wide deck still requires two base structures. (Two adjacent 4' x 8' decks still requires two base units.)  At that point, doesn't my original concern come into play?

I will take your advice and look more closely at the StageRight system.  I know the local "big boys" provider 115 miles to the west has some StageRight decking.  I'm not sure about the other local guys (only 65 and 90 miles away) have for decking. I don't think there is any decking available closer than 65 miles away, so I'm pretty sure I'll be filling a local niche.  Am I correct that while different brands are not directly compatible, any 4' x 8' deck system can be used along side a different 4' x 8' (or 4' x 4') deck system?

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Scott Holtzman

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Re: Another bonding question
« Reply #3 on: October 17, 2020, 09:52:25 pm »

Scott, thank you for your reply. I have only read the on-line material about the StageRight decks. IIRC, they are designed to "share" supports with adjacent decks, via non-metal locator pins attached to the base structure.  Does the construction or spacing of the locator pins force a mechanical (electrically bonded) connection between adjacent decks?

It looks to me that the StageRight decks are designed to be used in groups of three (two base units, with one deck spanning the gap between bases). Unless I've missed something (quite possible due to having 4 broken ribs and the pain from that), having a two-wide deck still requires two base structures. (Two adjacent 4' x 8' decks still requires two base units.)  At that point, doesn't my original concern come into play?

I will take your advice and look more closely at the StageRight system.  I know the local "big boys" provider 115 miles to the west has some StageRight decking.  I'm not sure about the other local guys (only 65 and 90 miles away) have for decking. I don't think there is any decking available closer than 65 miles away, so I'm pretty sure I'll be filling a local niche.  Am I correct that while different brands are not directly compatible, any 4' x 8' deck system can be used along side a different 4' x 8' (or 4' x 4') deck system?


Even with two decks I would still use locators to keep them from sliding apart, and yes they provide the boding, and the contact of the edges.  The stage itself is fiberglass and insulated. 


Sure you can mix deck and fiddle to get it even.  That's a royal pain in the ass though.  Certainly if someone comes to town and needs more deck they are not going to want to do that.  We also have outdoor ME's the next step up from the z-braces.  They have basically integrated screw jacks for leveling on outdoor surfaces.  I can't imaging anyone putting bonding straps between deck, never seen that done.  There are people with far more experience than me here that can answer that.


As far as markets.  I am not a huge provider.  8 years ago when I wandered in here I barely had 3 usable rigs and was doing bar gigs and the occasional private.  While we have more audio gear that has never proved to be a huge money maker, though the QSC KW stuff is now 10 years old, we have a pile of it and it has paid for itself 10x.  The real high profit items that go out all the time is pipe and drape and stage.  It's just solid money.  Next is monitors and totems and then projectors, usually with a wireless and the aforementioned powered boxes.  If it wasn't for that business we could not do the bands we like and the stuff we enjoy.  I am in Cleveland so we get lots of tours, corporate, trade shows and sporting events.  All of those need staging, when the big guy runs out they call the second on the list and then us.  It's a nice niche.  The Wegner was a "getting our feet wet" purchase.  The Stageright was one of the best investments I ever made next to a trailer full of pipe and drape I bought from a major cosmetics company that wound down a road show.  I had to take a whole bunch of junk but there were 6 hampers with fire certs of Rose brand heavy velvet drape and a metric shit ton of bases, uprights and crossmembers.  Drape and stage pays the bills. 


Best of luck to you.
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Stephen Swaffer

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Re: Another bonding question
« Reply #4 on: October 19, 2020, 12:30:32 pm »

To address the bonding issue, I would use something like these:

https://www.cesco.com/Ilsco-TA-2-Ilsco-TA-2-Dual-Rated-Solderless-Mechanical-Lug-Connector-1-4-Inch-Bolt-Size-14-2-AWG-or-2-14-10-AWG-Copper-or-2-12-10-AWG-Aluminum-1-Hole-Mount-6061-T6-Aluminum-Alloy-Electro-Tin-Plated/p2154260

The key is they are "dual rated"-copper and aluminum so they should not have a problem with electrolytic corrosion.

As far as bonding to the service, to me the ideal place is to bond at the load end of the distro.  I would make a place to bolt a similar lug to the frame of the distro.  Your bonding is only required to be sized per the breaker feeding it-so that bond is the same throughout the application.  #6 for interconnections is not a bad idea as it is adequate for up to 100 amp services and is more mechanically robust than #10 (all that is required at 50 amps).
« Last Edit: October 19, 2020, 02:14:27 pm by Stephen Swaffer »
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Mark Cadwallader

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Re: Another bonding question
« Reply #5 on: October 19, 2020, 01:09:57 pm »

To address the bonding issue, I would use something like these:

https://www.cesco.com/Ilsco-TA-2-Ilsco-TA-2-Dual-Rated-Solderless-Mechanical-Lug-Connector-1-4-Inch-Bolt-Size-14-2-AWG-or-2-14-10-AWG-Copper-or-2-12-10-AWG-Aluminum-1-Hole-Mount-6061-T6-Aluminum-Alloy-Electro-Tin-Plated/p2154260

The key is they are "dual rated"-copper and aluminum so they should not have a problem with electrolytic corrosion.

As far as bonding to the service, to me the ideal place is to bond at the load end of the distro.  I would make a place to bolt a similar lug to the frame of the distro.  Your bonding is only required to be sized per the breaker feeding it-so that bond is the same throughout the application.  #6 for interconnections is not a bad idea as it is adequate for up to 100 amp services and is more mechanically than #10 (all that is required at 50 amps).

Thank you. That is all very helpful.  Mark C.
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frank kayser

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Re: Another bonding question
« Reply #6 on: October 21, 2020, 12:22:08 pm »

I'm trying to perform my due diligence while thinking (daydreaming?) about buying portable stage decks.  I'm considering the Wenger StageTek aluminum framed deck units, although there are a number of similar items from other companies.  There is a four inch (100 mm) aluminum extrusion that runs the perimeter of the individual deck units. There is probably some aluminum to aluminum contact between the individual deck units, but there is no hard mechanical connection (as would be the case with a coffin lock) deck to deck once the stage is assembled.

Assuming that I have set up the stage on the grass in a park, is it prudent that I modify the stage decks to run a stranded copper wire jumper (like 12 AWG) that connects a deck to an adjacent deck, so that all of the decks are bonded to one another, and then run a heavier wire (like 6 AWG) to bond to whatever electrical service I'm using?  I've read a couple of prior threads on the topic that seem to suggest that one should, but there has not been an explicit discussion saying it is appropriate to actually connect wire jumpers deck to deck.  Setting up a portable stage indoors I've never seen it done (or suggested), but outdoors seems like it might be a different situation to consider.  Am I over-thinking this, and just adding unnecessary work to my setup and strike?  I note that StageLine trailers have a specific lug to "ground" the trailer.

Along the same line of thought, how specifically do I go about actually making the bonding connection to the electrical service?  A common scenario is that there is 50 amp 240 volt service (via a NEMA 14-50 outlet) that I'm connecting to my distro. To what do I attach my 6 AWG stage bonding wire?  The service is run to a free-standing pedestal for plug and play connections.  I assume that a licensed electrician will not be standing by help me.

I can leave the issue of what to do if I'm using a small generator (under 5000 watts rated power) instead of plugging into the grid for another day.

I look forward to hearing the collective wisdom from the forum.  Even if I don't move forward with my idea, it is still probably worth my thinking about.


Hi Mark,
Back in 2014 I had similar concerns.  I'm not sure I really got the answer I was looking for, but lots of good info anyway.  In lieu of anything definitive or rated for use, liability exposure, and absolutely "I don't know nuthin' about no elektrictiy grounding of our stage decks" from the decking manufacturer, I went with GFCI in each box in my stringers, and any feeders to said stringers.  That and the city supplied electricity is from GFCI equipped outlets.  The GFCI of the city space are somewhat questionable operational status...  But that was neither here nor there...

Take a read on this thread to see if it answers any of your questions.

https://forums.prosoundweb.com/index.php/topic,148617.0.html


frank
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frank kayser

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Re: Another bonding question
« Reply #7 on: October 21, 2020, 01:07:38 pm »


Hi Mark,
Back in 2014 I had similar concerns.  I'm not sure I really got the answer I was looking for, but lots of good info anyway.  In lieu of anything definitive or rated for use, liability exposure, and absolutely "I don't know nuthin' about no elektrictiy grounding of our stage decks" from the decking manufacturer, I went with GFCI in each box in my stringers, and any feeders to said stringers.  That and the city supplied electricity is from GFCI equipped outlets.  The GFCI of the city space are somewhat questionable operational status...  But that was neither here nor there...

Take a read on this thread to see if it answers any of your questions.

https://forums.prosoundweb.com/index.php/topic,148617.0.html


frank

Another thread from 2014...

https://forums.prosoundweb.com/index.php/topic,150403.0.html

Mark, I believe you were a contributer on this thread, too.  Note particularly Jonathon Johnson's post about who should take on the bonding responsibilities and liability.  Food for thought.

frank
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Mark Cadwallader

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Re: Another bonding question
« Reply #8 on: October 21, 2020, 04:23:52 pm »

Another thread from 2014...

https://forums.prosoundweb.com/index.php/topic,150403.0.html

Mark, I believe you were a contributer on this thread, too.  Note particularly Jonathon Johnson's post about who should take on the bonding responsibilities and liability.  Food for thought.

frank


Frank, thank you for posting those links. I didn't find them on my first (only) try using the search feature.  I had a vague recollection of this concern being discussed before, somewhere, but you've found them for me.  I'll raise a libation in your honor, sir.

I bet if I looked back at my records I would notice that I bought a bunch of in-line GFCI devices around the time of this discussion, and that's (one of the reasons) why I have so many sitting on the shelves next to my Edison extension cords.
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frank kayser

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Re: Another bonding question
« Reply #9 on: October 21, 2020, 10:47:10 pm »

Frank, thank you for posting those links. I didn't find them on my first (only) try using the search feature.  I had a vague recollection of this concern being discussed before, somewhere, but you've found them for me.  I'll raise a libation in your honor, sir.

I bet if I looked back at my records I would notice that I bought a bunch of in-line GFCI devices around the time of this discussion, and that's (one of the reasons) why I have so many sitting on the shelves next to my Edison extension cords.


You're welcome, Mark.  Back then this was a real hot topic for me. I was having nightmares about the 12yo girl in Salinas Kansas... The electrocution of two folks at National Harbor happened around the same time.  I was spooked. I was (up to last year) doing about six shows during the summer months.  The city had me going nuts - stage sections were not attached to one another, no stairs, and of course the electrical.
 
Through accident, I hooked up with someone who not only know where the stage decks were stored, but had a key.  He discovered a set of stairs.  Folks in Public works swore the stairs did not belong to the city.  Really? They finally figured out the stairs really did belong to the city.  I researched deck locking devices and costed them out.  Oh, Public Works said they had a bag of them stored with the decks.  Really?  Someone wants us to use them?  It took about three years of nagging the city to ALWAYS use the stairs, and ALWAYS lock the stage sections together.  With this year off, I know I'll have to start again next year.  Maybe I should stencil the instructions on the decks...


I showed up one Sunday around 7AM, and found a city-owned GFCI inoperable - ants nest... I had the opportunity to talk with the city electrician - nice enough, had no idea of the NEC and stage ground bonding.   Seems electricians are getting as specialized as lawyers...

The Jonathan Johnson post talking about liability pretty much killed my curiosity, and my effort to provide a safer deck.  Trying to be better and safer is more dangerous in the courts than burying one's head in the sand.  That's so much against my makeup - but hey, I like my house and car.  So I went the multiple GFCI route, and have not looked back.  I did what I could without playing in someone else's pool.


So, thanks for the raised libation.  If you're in town, we can have something for real.


frank


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Re: Another bonding question
« Reply #9 on: October 21, 2020, 10:47:10 pm »


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