I'm doing an arc Flash evaluation of my bldg distribution system, and I'm trying to understand why the calories vary so much under certain circumstances.
My example is I have 2 identical 480V power circuit breakers with 600 amp trips, one breaker feeds a 400kva 480-208/120 transformer, the...
Actually, Starline is the only manufacturer that makes anything similar in a 100 amp size. No one else does that I can find online. The problem with Starline is the attachment is similar to track lighting where you insert and twist to lock-in. I'm not that comfortable with that arrangement, so...
I work in a large research lab with many individual lab spaces. For the last 50 years, we have used GE DH bus duct rated at 3 phase, 208 volt, 100 amps. That product is no longer available and parts are getting harder to find, so I was wondering what others might be doing for bringing similar...
We have been using an EPO circuit for 25 years for laboratory rooms, invented by someone back in the day. It's not good but it works, usually. Sometimes it doesn't.
I attached a diagram of the circuit. Basically, diodes are used to allow for indicating lights when power is ON or when the...
I'm looking at this one right now, which is supposedly all purpose, and the only one of its kind on the market in that it works with or without ballast,any electronic or magnetic(some) but I just tested it with 30 year old T12 magnetic ballast and it did not work.
http://msissl.com/#!/t8
I am looking at replacing the 250 watt metal halide lighting in my parking lot. It appears that the new style of fixture(Cree ARE-EDR-5M-R5) that consists of an array of LED's is not intended to have a field replaceable bulb. Cost of new fixture is about $1200. Retrofit bulbs are now available...
That's why I'm asking whether it can be done energized. I only want to reduce the arc flash hazard for the 2 or 3 hours it takes to do the work. Then the settings would be returned to where they were.
I have switchgear with GE AK breakers. In doing calculations(SKM Software), I have determined that if I reduce the instantaneous setting to 1.5 I can limit the arc flash exposure. My question is if I can turn the dial while the breaker is energized.
After re-reading the code section several times, and finding some Mike Holt comments on the subject, it looks like you are correct. I do need that protective device before I go to any receptacle. Thanks for the input.
I have a situation where I have an existing 100 amp 3 phase service out of a panelboard. I would like to split the service in a junction box by terminating on a power distribution block and then feeding 3 individual 2 pole 30 amp receptacles mounted in the side of the jbox. There are #1AWG...
Some further info. This is the bulb I am looking at.
http://www.ledglobalsupply.com/led-commercial-bulbs/250-watt-hid-led-retrofit/
I'm thinking this lamp requires airflow around it and may not be suitable with a sealed parking area fixture.
I have some existing parking lot 250 watt and 400 watt metal Halide fixtures. They are Lithonia Polestars. The latest searches I do seem to indicate that there are LED equivalent bulbs, but they are expensive $200- $300. Has anyone tried to do this and had any issues with overheating. The...
I have an area that is classified Class 1 - Div 2. It is for hazardous material storage, and the classification is only should leakage of vapors occur. If I need to run an analyzer and print a report to a printer via plugging standard 6' 120VAC cords into haz location receptacles, am I...
