Attaching a 50', 14 AWG extension cord to a wall
- Thread starterturtle7896
- Start date
STEVETERRY
Well-Known Member
My original fault current statement was not directed at fully-evaluated Listed products, but to discourage the use of unlisted constant power "solutions" that create a potential safety issue. The issue of fault current coordination is often overlooked by end-users in our industry.
ST
STEVETERRY
Well-Known Member
Did UL (or ETL) test your modification in a high power lab? What portion of the I-squared-R loss and resulting fault current limitation came from the power cube and what part from the choke? If there is no third-party testing, your home-made bypass is relegated to a hobby effort.
Who will know?
Only the investigating insurance company when life or property is lost as a result of an incident.
Don't do it.
ST
Leaving the choke defeats the whole purpose of eliminating the dimmer. LED lights use switching power supplies. Switching power supplies draw current in short bursts, hence the name. Doing that through an inductor doesn't work at all the way the power supply designer intended. All of the fuss about not powering LED lights through dimmers is caused as much by the inductor as the SSR, probably more so.
turtle7896
Member
Alright. So, based on what @STEVETERRY has said, among everyone else, what is my best way to approach all of this? We need to change out 4 separate dimmers due to very, very inefficient power and horrible wiring done 30 years ago.
STEVETERRY
Well-Known Member
You have provided us with some new information that needs unpacking by someone in the field. "We need to change out 4 separate dimmers due to very, very inefficient power and horrible wiring done 30 years ago." What does this mean? This thread started out with getting constant power to some LED luminaires. If that is the presenting problem, I suggest that you get a licensed electrician to quote on extracting those circuits from your dimmer rack and connecting them to a new or existing breaker panel to provide constant power.
If "inefficient power and horrible wiring" (whatever that means) are also part of this project, the licensed electrician may be able to help on this as well.
Much as we would like to help further, I believe we have reached the safe limits of a productive online discussion. That's just my two cents.
Signing off now.
ST
RickR
Well-Known Member
If your system is so bad it might be time for an overhaul.
My 3rd cent is to recommend an independent consultant. A non-sales person, with broad experience can help you create a master plan for improvements. LEDs have altered the possibilities. Power, data, rigging, fixtures might all warrant review of their usefulness and safety. Step one might well be getting new circuits. But what happens then?
My 3rd cent is to recommend an independent consultant. A non-sales person, with broad experience can help you create a master plan for improvements. LEDs have altered the possibilities. Power, data, rigging, fixtures might all warrant review of their usefulness and safety. Step one might well be getting new circuits. But what happens then?
turtle7896
Member
Gonna be entirely honest because I don't think I have fully explained it. I'm literally a high-schooler in a significantly underfunded, under-supported, and understaffed stage crew. Half the time I have no clue what I am talking about, and somehow I know more than our IT person, which is the only person who helps me. We have no budget, and I am very thankful for all the help, because I have learned things from reading everyone's answers. As for what you said @STEVETERRY , I am just going to hope that I can convince my school to just get an electrician to come out to hopefully give us some help, thank you for everything. @RickR , I have been hoping that we will be getting a new system for 2+ years, and I have been told it will be at least 10+ years till we get something that is fully functional.
RickR
Well-Known Member
I've seen 2 things move an administration. A grant of funds and a safety risk. If you can get someone else to pay for it you can probably do what you want. If you can show a clear risk it will get handled, maybe by shutting everything down. Basically the risk of having to pay off law suits can make system upgrades look cheap.
There is an educational argument, but lack of funds makes it difficult to push forward. And such discussions fall into the realm of politics, a most adult pastime! So getting some adult backing is critical!
There is an educational argument, but lack of funds makes it difficult to push forward. And such discussions fall into the realm of politics, a most adult pastime! So getting some adult backing is critical!
turtle7896
Member
Unfortunately since I also attend a private school with absolutely no tax money, they divert all alumni or other money to sports, e-sports, and what ever else is "needed" because nobody really gives a crap about our auditorium besides me and like 2 others students. One of our eplisodals started smoking when I plugged it in. Although, I will try to get some more adult backing.
jtweigandt
Well-Known Member
Photos of the burn marks or shorted wiring inside that elipsoidal might go a long way to pique some adult interest. Asbestos gets attention too.
microstar
Well-Known Member
I am still trying to process the thinking regarding non-dim/constant modules and fault current thing. Here are top and bottom photos of a very recent non-dim module from a very reputable manufacturer.
No fuse, just the circuit breakers wired to the in/out connectors. What factors would lead to this being acceptable?
No fuse, just the circuit breakers wired to the in/out connectors. What factors would lead to this being acceptable?
STEVETERRY
Well-Known Member
Possibilities for this module:
1. The "reputable manufacturer" achieved only a low original fault current rating for the rack equal to the AIC fault current rating of the branch breakers. A typical rating would be 5,000 or 10,000 amps RMS symmetrical. Original Installers of such a rack would have had to limit the available fault current to not exceed the low rating of the rack. This might have been relatively simple on small feeders and very difficult on large feeders. In such a case, the pictured module would not be reducing the rack fault current rating, since the rack rating is already as low as it can get.
2. The "reputable manufacturer" might have ignored the fact that the breaker-only module would reduce the original fault current rating of the rack, if the original rating was above the native rating of the branch breakers. Putting it politely, this module might be an effort of the uninformed. A careful study of the manufacturer's Listing data would be required to determine:
A. Is the pictured module even Listed?
B. If it is Listed, are there associated instructions or labels that warn of a reduction in original rack fault current rating to the native rating of the module breaker? Are there other conditions of use that explain why it is OK?
If you identify the manufacturer and model number of the module, more details might be possible.
ST
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