General Electrical Questions...

K

Kip Conner

Junior
Mar 13, 2011
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Athens, GA
I'm getting ready to upgrade some stuff for a much local sound company. I have a gig that i do yearly that requires me to very much walk the line when it comes to amperage. The outdoor venue has a 30amp service outlet and several 15amps and they will provide me with a distro that is loaded with 8 15amp circuits on GFI's that plugs into the 30amp. Even the band gear on it's own stringer will trip the GFI's. I'm thinking about building another small distro that is non GFI. It's your typical outdoor gig that needs more power than is available.

I'm going to request information from the city to assist in making this thing, what questions do I need to ask? I'm guessing I need to know the total amperage to point where this 30amp plug/ multi15amp is located. This distance from the outlet that I will be using to the distro will about 4 feet.

I can't really afford to buy a pre-made spider box so I'm going to just built a simple panel with a 4 wire input and hopefully 8 20 amp circuits.

I've installed circuits into a panel before and am quick with wiring electrical so I'm confident I can build one. I'm mostly concerned with no overloading the amperage that is available to me.
 
Re: General Electrical Questions...

1. GFCIs do not trip because of excessive current. If you're tripping GFCIs you either have a major wiring problem, one of the amps is old and has a wiring problem, or the GFCIs are bad (very common for GFCIs to go bad).

2. Once you build a custom spider box (correctly) you'll have spent as much as it would cost for the Ampshop or whoever to make one for you. Don't even bother to do it yourself, the liability isn't worth it anyway. A box from Ampshop to do this will be less than $200.

3. Have you ever tripped the breaker for the 30A receptacle? If not, you're not walking the current line.

4. Putting eight 20-amp circuits on a 30 amp 240V receptacle is legal, but pointless. Four 20A circuits make sense.
 
Re: General Electrical Questions...

Kip Conner said:
I'm getting ready to upgrade some stuff for a much local sound company. I have a gig that i do yearly that requires me to very much walk the line when it comes to amperage. The outdoor venue has a 30amp service outlet and several 15amps and they will provide me with a distro that is loaded with 8 15amp circuits on GFI's that plugs into the 30amp. Even the band gear on it's own stringer will trip the GFI's. I'm thinking about building another small distro that is non GFI. It's your typical outdoor gig that needs more power than is available.

I'm going to request information from the city to assist in making this thing, what questions do I need to ask? I'm guessing I need to know the total amperage to point where this 30amp plug/ multi15amp is located. This distance from the outlet that I will be using to the distro will about 4 feet.

I can't really afford to buy a pre-made spider box so I'm going to just built a simple panel with a 4 wire input and hopefully 8 20 amp circuits.

I've installed circuits into a panel before and am quick with wiring electrical so I'm confident I can build one. I'm mostly concerned with no overloading the amperage that is available to me.
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I would isolate the backline gear that is leaking. The GFCI is telling you something! This distro project might be a bad idea....

You may be required (by code) to have 'standard' outlets accessible to those who are not trained and authorized (and used outdoors) protected by GFCI.

If you want a cheap non GFCI distro, I've got 6-8 extra of these that will be cheaper than making something new. I might even have a 14-30 plug which I assume is they are using (it better have a neutral!!!!! - No RV plugs, etc).

2010-10-07 21.43.36.jpg2010-10-07 21.43.12.jpg
 
Re: General Electrical Questions...

Marlow- this is exactly what I am talking about building and I already have the 14-30 connector on hand. How much for one or two of your spares? And how much trouble is to get through customs?

I know the GFI's are bad but I can't convince the backwoods facility guy of that- they trip way before a 15amp pull on them. When I say I'm walking the line with power, it's these 15amp GFI's that are my problem. The 30amp service is mostly likely fine- I just have to get their make shift "distro on a dolly" thing out of the equation.

It's an odd situation because "no one else that does shows out here has this problem". The other shows don't require six mixes, double the FOH, a delay cluster, a rear fill and a side fill. It's a typical city event. They don't pay the artist very well because it's a not for profit. It just happens to support the downtown area of the town I live in so I give them a huge discount.
 
Re: General Electrical Questions...

Looking on the AmpShop page the very first thing is what I was looking to do. Not a "real" distro by any means- just a distributed power source.
 
Re: General Electrical Questions...

Kip Conner said:
Marlow- this is exactly what I am talking about building and I already have the 14-30 connector on hand. How much for one or two of your spares? And how much trouble is to get through customs?

I know the GFI's are bad but I can't convince the backwoods facility guy of that- they trip way before a 15amp pull on them. When I say I'm walking the line with power, it's these 15amp GFI's that are my problem. The 30amp service is mostly likely fine- I just have to get their make shift "distro on a dolly" thing out of the equation.

It's an odd situation because "no one else that does shows out here has this problem". The other shows don't require six mixes, double the FOH, a delay cluster, a rear fill and a side fill. It's a typical city event. They don't pay the artist very well because it's a not for profit. It just happens to support the downtown area of the town I live in so I give them a huge discount.
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PM sent regarding equipment. Thinking about it more, I'm surprised the Sound Co. doesn't have a little 14-50 distro for hotel ballrooms and the like. Anyways, some might call this heretical, but you can always make a little 14-30 male to 14-50 female adaptor (though not the other way around!). I'm not endorsing it as code compliant per say...
 
Re: General Electrical Questions...

Kip Conner said:
I know the GFI's are bad but I can't convince the backwoods facility guy of that- they trip way before a 15amp pull on them. When I say I'm walking the line with power, it's these 15amp GFI's that are my problem.
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Kip-

You need to read Silas' post. The GFI is tripping because you have a ground fault, or it's defective; GFIs *do not* trip because of load.

Do a google search for "how do GFCI work?"
 
Re: General Electrical Questions...

Tim McCulloch said:
Kip-

You need to read Silas' post. The GFI is tripping because you have a ground fault, or it's defective; GFIs *do not* trip because of load.

Do a google search for "how do GFCI work?"
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+1. Except I still think there is something to be said for owning a small distro/pdu/distributed power source/whatever. The problem here is if the the GFCI is faulty he can't fix it and if some faulty backline is the problem he can't fix it either. I'd much rather rely on whatever I bring over some of the scary shit I've seen. My go-to 'baby' distro lets me go safely from 50 amp (CS or 14-50) to a couple GFCI 20a outlets, a couple non-GCFI 20a outlets, and two L14-30's to feed amp racks or something else. In the grand scheme of things this was not expensive and there's some peace of mind knowing that I can handle most situations that might arise.
 
My distro is not gfci. However, I have stage stringers with powercon and in the event of an inspector wanting gfci protection, I have one box I put at the start of a string with gfci outlets in it and the output powercon connected to the load side of the gfci. Problem solved.
Of course, you really need to identify the gear that is tripping gfcis and fix it.



Sent from my iPhone
 
Re: General Electrical Questions...

Tim- I did read it and I understand his point and clarified that I know the circuit is good and the and the GFCI's are bad.
 
Re: General Electrical Questions...

Rob Spence said:
My distro is not gfci. However, I have stage stringers with powercon and in the event of an inspector wanting gfci protection, I have one box I put at the start of a string with gfci outlets in it and the output powercon connected to the load side of the gfci. Problem solved.
Of course, you really need to identify the gear that is tripping gfcis and fix it.
Sent from my iPhone
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That's a pretty slick way of doing it! The other thing I have (though I rarely use it) is a heavy duty 20a GFCI cordset from a defective portable hottub. It's much better than the Home Depot type things I've seen and let's me achieve the same thing of making non-GFCI power appropriate for outdoor use. That said, I still prefer the GFCI breakers, having been frustrated by some of the cheaper outlets and cordsets. The t-slot 20a GFCI outlets are now readily available and may be better than the older 15a ones. I know the two-pole GCFI breakers are falling out of favour for residential kitchens (due to cost) and the codes here allowing the 20a outlets instead now.

*Edit* Maybe semantics, but it's worth pointing out that a non-GFCI outlet that you plug your GFCI cordset into may still be enough to make you non-compliant. The exception, I think, is to make anything non-GFCI a twistlock (or maybe powercon, but I haven't gone that route). This will be especially true if the distro is accesible AND outdoors. My experience is usually running power from inside to outside. In either case you're getting into somewhat murky interpretative aspects that will vary from place to place. My experience is that the variation between Quebec and Ontario (I live right on the border) is often greater than between Quebec many US states. Advice will be to talk to the inspector, who invariably won't have any really obvious guidance or even be easily reached.

You might be better off calling a local generator company (maybe start with a local Sunbelt?) and find out what there experience is and what they have available to rent. Renting may be cheaper than trying to build something for a one-off.
 
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Re: General Electrical Questions...

Marlow Wilson said:
That's a pretty slick way of doing it! The other thing I have (though I rarely use it) is a heavy duty 20a GFCI cordset from a defective portable hottub. It's much better than the Home Depot type things I've seen and let's me achieve the same thing of making non-GFCI power appropriate for outdoor use. That said, I still prefer the GFCI breakers, having been frustrated by some of the cheaper outlets and cordsets. The t-slot 20a GFCI outlets are now readily available and may be better than the older 15a ones. I know the two-pole GCFI breakers are falling out of favour for residential kitchens (due to cost) and the codes here allowing the 20a outlets instead now.
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Whether a GFCI receptacle is 15A or 20A has little relevance to its maximum current capacity, since 15A receptacles are allowed on 20A circuits, and the load side of even a 15A GFCI is still rated for 20A.
 
Re: General Electrical Questions...

Silas Pradetto said:
Whether a GFCI receptacle is 15A or 20A has little relevance to its maximum current capacity, since 15A receptacles are allowed on 20A circuits, and the load side of even a 15A GFCI is still rated for 20A.
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It's not a current thing. The Home Depot 15a outlets I've seen on some distros are just not designed for the use they are subjected to. Some are cracked, some are faulty, some don't work at all. It's a build quality issue more than anything.
 
Re: General Electrical Questions...

Marlow Wilson said:
It's not a current thing. The Home Depot 15a outlets I've seen on some distros are just not designed for the use they are subjected to. Some are cracked, some are faulty, some don't work at all. It's a build quality issue more than anything.
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Could be. Buying industrial vs residential is likely going to offer a bigger jump in quality. Everything at Home Depot, 20A or not, is homeowner crap.
 
Re: General Electrical Questions...

Silas Pradetto said:
Could be. Buying industrial vs residential is likely going to offer a bigger jump in quality. Everything at Home Depot, 20A or not, is homeowner crap.
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My point is that when I see GFCI outlets, I'm reminded of the crap. The US adopted 20amp t-slot stuff WAY before Canada. Until quite recently, in Canada 20 amp = industrial for the most part. I think the distinction is still in my mind, though perhaps increasingly in error.
 
Re: General Electrical Questions...

Marlow Wilson said:
My point is that when I see GFCI outlets, I'm reminded of the crap. The US adopted 20amp t-slot stuff WAY before Canada. Until quite recently, in Canada 20 amp = industrial for the most part. I think the distinction is still in my mind, though perhaps increasingly in error.
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I see. Yes, Home Depot has plenty of 20A stuff, and it's all homeowner grade.

Code here has required 20A circuits in kitchens and bathrooms for quite a while...
 
Re: General Electrical Questions...

All I can add to this GFCI debate is that we send thousands......thousands....back every year to the manufactures as defective right out of the box.
It is our single biggest defective product that we sell in Electrical Distribution (Besides combination Smoke/Co detectors).
And that is from EVERY major manufacturer.
Leviton, Hubbell, Arrow Hart (Cooper.....which includes P&S)..
 
Re: General Electrical Questions...

Hi Marlow-

Your point about using twist lock or PowerCon is something to be considered. In the USA, Code most often refers to "outlets for use by personnel" in discussions of GFIs (along with outdoors, garages, within 6' of water, etc). Our local inspector explains "for use by personnel" as to mean that the outlet uses a common, everyday connector (Edison 15 or 20 amp) and that it is accessible for use by any person regardless of qualifications.

Keeping that in mind, anything that uses a non-Edison connector; or an Edison that is not generally accessible to non-qualified persons (back line techs, the public, etc) *probably* meets that standard. Use of twist locks or PowerCon would meet that requirement, as would Edison outlets that are not for use by, or generally accessible to, non-qualified persons (back of an amp rack, on the front of a distro or rack pack).

Every inspector sees things a little (or a lot) differently than the next guy in the inspection office. We've only been questioned once about this, and when I was able to tell the inspector who we talked to previously, he said, "Oh, if Bob said it's good I'll let you go this time." Not sure if "Bob" is higher ranking or just internally seen as the go-to guy for entertainment compliance or if the events we work are no longer on their list of things to pay extra attention to, but it's not come up again.

There are also Code exceptions to GFI requirement for certain "sensitive" electronic devices, but I've yet to meet any inspector who considered a Fender Twin to be "sensitive."
 
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