UL Who?

Steve Milner

Steve Milner

Junior
Jan 10, 2011
298
0
16
Washington, dc
www.dcsoundop.com
Just saw this posted for sale in the marketplace here. . . I'm not trying to call out anyone for doing anything intentionally wrong... but this could be a potentially dangerous situation being passed along to an unsuspecting buyer.

I love a good DIY project... but power is not the place to make mistakes. This is pretty scary looking to me... especially if it's intended to be riding around in a rack all the time.

attachment.php


Again, no disrespect intended to the owner... I hope this is taken in the spirit of these forums and with the intent that we can all learn from our individual mistakes.
 
Re: UL Who?

Adrian, you're fired. HA!

However that should be enclosed, UL isn't the right regulating authority to be calling out on this one. Most distros are NOT UL listed, except maybe Motion Labs. For example, nothing AmpShop makes is UL listed, but electrical inspectors usually look for what looks 'legit' versus what looks 'custom' and therefore most anything AmpShop makes would pass.

And, there might even be a line that once that panel is in the rack, it is enclosed.

Steve, besides enclosing the back of the panel, what else would you change? Let's make this a learning experience.

I can see that there should be a bushing or some sort of cord grip for the THHN rather than a Romex connector.

Edit: The panel above uses the correct connectors and correct size wire for the Powercon on the other side. I can vouch that internally, it is properly pigtailed and assembled with crimped connectors on the screw terminals. There is no 'push' wiring in there, like most consumer receptacles.

The difference between average Joe doing a custom panel like this, and someone that knows code and proper conventions, is that even though that panel looks ugly, it's not going to catch on fire/electrocute anyone/fail. Whereas, if average Joe did one and it was enclosed, but all wrong internally, the potential for failure would be far higher.
 
Last edited:
Re: UL Who?

That would be hard to get away with here (Ontario), where the government hydro authority is all over having anything to do with electrical inspected and stickered to show it complys.
It can be a pain when the inspector shows up and you have a bunch of gear that shipped to you on tour direct from the US or Uk, but it is done for everyone's safety.

The entire assembly would need to be enclosed in a grounded metal back box without holes and have a breaker on the incoming line.
The same internal wiring would probably be ok, a picky inspector might want black for the hot leads.
 
Re: UL Who?

A non-exhaustive list of what's wrong:
THHN wire used outside an approved enclosure
Exposed Powercon terminals outside an approved enclosure
THHN wire in a cable clamp.

It's up to the inspector to determine what's legal (or close enough) or not in any situation, but generally speaking, the inside of a rack case does not qualify as an enclosure. This is true for several reasons - no mechanical protection of the mains wires, no barrier between mains voltage systems and low-voltage wire, and a flammable enclosure.

There is a boundary between premise wiring and appliance wiring. If this device is considered an appliance, it's likely that there would be need for a circuit breaker, among many other UL-mandated changes since they aren't governed by the NEC. If this is considered by the inspector du-jour as temporary power distribution, the rules may be closer to what the NEC requires.

Silas - I'm not entirely sure what your last paragraph means, but if you are considering this as something done by someone that knows code and conventions, I would suggest that this is pretty dangerous with two obvious shock hazards - the exposed Powercon terminals, and the metalic clamp on the THHN wire. Hopefully such a "knowledgeable" person would do a better job.
 
Re: UL Who?

I'm fairly certain that having exposed wire nuts is a no-no as well. It doesn't take too much to knock them loose and then you have exposed hot wire knuckles. "Hmm, that quad went dead. I'll just reach around behind this rack and wiggle the wires..." Bzzt.
 
Re: UL Who?

Silas;
T.J. beat me to responding... and I am not an electrician, but the exposed backside of the powercon connectors along with the amount of tension that is on the wires going between the powercons and the wire nuts looks a bit risky. I leave the electrical work to the pros, and most of my experience professionally is with UL listed devices such as those offered by Motion Labs.

In my experience, electrical work that looks sloppy, generally has more issues hiding below the surface mess. You can say that a sloppy wiring job can still be safe and work properly, but tidy and well planned out work is always going to be safer in the long run when being expected to stand up to real world use in our industry. One big bump in the trailer to jar a wire nut loose or one unsuspecting stage tech reaching into that rack to plug something in... and you could have a life threatening situation on your hands.

Also, I am not even remotely informed on this topic, but I do believe the scope of UL 1640 [Portable Power Distribution Equipment] would indeed cover this type of device. I hope someone who is more informed can comment on the different governing bodies in here in the US and how they pertain to such devices. Everyone seems to have good info on getting approval stickers in Canada... but I haven't heard much about the process in here in the States.
 
Last edited:
Re: UL Who?

"The difference between average Joe doing a custom panel like this, and someone that knows code and proper conventions, is that even though that panel looks ugly, it's not going to catch on fire/electrocute anyone/fail"

unless the THHN shorts to the metal components, shocking the shit out of someone

HUGE liability. Think people. Think.
 
Re: UL Who?

Steve Tarak said:
"The difference between average Joe doing a custom panel like this, and someone that knows code and proper conventions, is that even though that panel looks ugly, it's not going to catch on fire/electrocute anyone/fail"

unless the THHN shorts to the metal components, shocking the shit out of someone

HUGE liability. Think people. Think.
Click to expand...


The rack that this was in had rack blanks in the back, closing it off from people reaching in the back, that gets rid of the human element. And the ground was tied to the blank, so if anything shorted, the breaker would have tripped.
 
Re: UL Who?

For UL approval they don't just consider "as used" or "recommended practice". They look at the unit, and if the chassis has holes in they stick metal probes through those holes looking for a shock hazard.

I would draw a large distinction between the things people make to use themselves, that mainly put themselves at risk, and things that are sold to others, who may not appreciate the importance of protecting the back from probing fingers or whatever.

While even the stuff we build for our own use should be safe.

JR
 
Re: UL Who?

There really should not be any exposed wire nuts. All those connections should have been in a box (and one is handy).

The wires should all have been secured so they can not flop around and should enter the box through a bushing.

A metal cover over all the exposed wiring and Powercon rear would go a long way to improve things.
 
Re: UL Who?

Yes. Junctions go in boxes, unequivocally. You could probably make a reasonable argument that the road case was the "box," but that's not how this is being sold.

Does anyone know.. for commercial use, do all boxes need to be ground-bonded metal enclosures?
 
Re: UL Who?

Lee Dickinson said:
Yes. Junctions go in boxes, unequivocally. You could probably make a reasonable argument that the road case was the "box," but that's not how this is being sold.

Does anyone know.. for commercial use, do all boxes need to be ground-bonded metal enclosures?
Click to expand...

I think that if it is metal, it needs to be grounded. I have seen plastic boxes used too.
 
Re: UL Who?

Lee Dickinson said:
I just wasn't sure if plastic boxes are even allowed in our industry. Say, plastic stage drop boxes, for example. (Drifting off topic a bit, I know.)
Click to expand...

I'm almost 100% sure they are, since all the weatherproof stuff made for such a purpose isn't metal. In fact, using any sort of metal boxes with knockouts (that always get pushed in) is strongly frowned on.

I'm a huge fan of the heavy-duty PVC weatherproof boxes since they're easy to drill and work with for custom connectors (powercon).

Everyone has seen the stage stringers made from 4" square boxes using Romex connectors and a slew of Home Depot parts, where it's all loose and falling apart, and the guy using it just doesn't realize the problem.
 
Top Bottom