LED Christmas Lights on a dimmer
- Thread starterCBR372
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shiben
Well-Known Member
What!?IMHO, the attraction is totally incongruous with Frontier Trail, which in my day
was lit with gaslamps, IIRC. No really, gaslight. And before a smart aleck asks, NO, it wasn't because the incandescent bulb had not yet been invented.
Well if you had electrical lights why didnt you use them? Did they not have electricity up there while you were there? I know it took a couple dozen years to get all that "national grid" stuff done...
From History of OSHA, the NEC and NFPA Training :
Like most NFPA documents, 70E is on a three-year revision cycle. Current Edition: 2012 Next Edition: 2015.
Thanks for all the wonderful responses guys. One quick question though. i was already planning on putty a dummy load on them, however you use the term "inline" and I was wondering if you could elaborate. What I translate that is have a cable run from the circuit to a twofer with one tail going to the LED's and the second to an incandescent fixture offstage. Am I correct? If not a clarification would be great!
shiben
Well-Known Member
Well that explains why I found a 2009 site and a 2012 site?
Morte615
Active Member
Yep that's it exactly! Also if you are worried about extra light leakage you can use an LED Snubber instead and it will work the same without throwing anymore light. At some point today when I get to a real computer, and not my phone, I will update the wiki and give some instructions on how to build one, or some places that they can be purchased.
shiben
Well-Known Member
Re: Arc Flash and hot swap dimmer modules
Are the arc flash suits like the bomb disposal suits, in that they just make you easier to ship home in a box (rather than a lot of them), or do you actually make it thru? Either way it seems like something I dont really want happening to me
And either way, what the dude was doing in the video looks like something that was indeed unsafe but something that I would guess most of us have done at some point or other...
Are the arc flash suits like the bomb disposal suits, in that they just make you easier to ship home in a box (rather than a lot of them), or do you actually make it thru? Either way it seems like something I dont really want happening to me
And either way, what the dude was doing in the video looks like something that was indeed unsafe but something that I would guess most of us have done at some point or other...
Re: Arc Flash and hot swap dimmer modules
DISCLAIMER: I am not an expert on arc flash.
Arc flash is nothing to screw with. I know a fellow that had a 480 V motor center explode in his face. He spent weeks in a burn ward and is permanently scarred. He wasn't even touching live parts at the time. All he did is open the access door and press the start button. The arc wasn't extinguished until a fuse on the power line feeder opened, taking out power to the whole neighborhood.
The protective clothing amounts to pants, long sleeve shirt, and gloves made up of cloth that doesn't burn or melt for the duration and temperature typical of arc faults. (Fabrics melted onto burned skin make the wounds very difficult to treat.) You can buy shirts and jeans that look like normal ones, but are tested to offer protection. A full-face shield and hard hat is normally worn, too.
Let me put it simply: There is no excuse, N-O-N-E, to work inside a live piece of equipment. No amount of protective clothing makes it really safe.
There is some ongoing discussion as to whether 208 V is a high enough potential to cause an arc flash. Regardless, even 120 V can easily kill you, so it deserves full respect.
DISCLAIMER: I am not an expert on arc flash.
Arc flash is nothing to screw with. I know a fellow that had a 480 V motor center explode in his face. He spent weeks in a burn ward and is permanently scarred. He wasn't even touching live parts at the time. All he did is open the access door and press the start button. The arc wasn't extinguished until a fuse on the power line feeder opened, taking out power to the whole neighborhood.
The protective clothing amounts to pants, long sleeve shirt, and gloves made up of cloth that doesn't burn or melt for the duration and temperature typical of arc faults. (Fabrics melted onto burned skin make the wounds very difficult to treat.) You can buy shirts and jeans that look like normal ones, but are tested to offer protection. A full-face shield and hard hat is normally worn, too.
Let me put it simply: There is no excuse, N-O-N-E, to work inside a live piece of equipment. No amount of protective clothing makes it really safe.
There is some ongoing discussion as to whether 208 V is a high enough potential to cause an arc flash. Regardless, even 120 V can easily kill you, so it deserves full respect.
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tjrobb
Well-Known Member
Two things, and yes, I am a member of NFPA. First, the larger suits, class three and four, provide roughly enough protection to limit injuries to a survivable amount of second-degree burns. Second, technically any voltage can arc, but DC is more prone to sustaining an arc. IIRC, 277 volts is the lowest common AC voltage that can create a self-sustaining arc, the lower voltages extinguish themselves on the polarity reversal.
A snubber is used to control mechanical or electrical vibrations. In dimmers it is part of the dimmer circuit around the TRIAC or SCRs, When the waveform is switched on and off it produces harmonics of the 60Hz. The amplitude and frequecies produced depends upon the phase angle. The problem with the harmonics is they can cause vibration in transformers and inductors wound on metal formers - heard as noise and they can also produce interference with other electronic equipment. The interference may be at harmonic frequencies where the wiring acts as an antenna radiating energy or simply conducted through to other equipment over the supply cables. The snubber acts to filter these harmonics by providing a low impedance path to the return wire. Usually implemented as a resistor, capacitor and inductor network but can be realised using other components. Also limit the transient response which also produces harmonics. The design of an effective snubber circuit requires detailed information re the rest of the circuit design and its operating conditions.
An example of mechanical snubbers include shock absorbers or dampers
