I concur with the wire color problem. * My current employer pays big bucks to a low voltage guy who wires up our sites. His work is absolutely beautiful. It's like friggin artwork. He uses black for return (+) and green for ground. Then since most of our equipment has dual power supplies he uses red and blue for the "A" hot and "B" hot. I assume his employer trained him that way for a reason and that's probably common.
* I was taught in childhood that red is positive, so that's what I have always done. I'm not philosophically opposed to the idea that red is "hot", but that's just now how I learned it. * https://ztlabels.com/blogs/news/dc-power-circuit-wiring-color-codes This site advises that for 2-wire DC with positive ground is white for positive and black for negative. Someone apparently thinks that's the right way. The same site points out that the only color called out specifically in the NEC is green or green/yellow for ground. Everything else is just the convention people landed on. Out in the wild you might see anything so there is and will always be a multi-meter in my everyday toolkit. -Adam -----Original Message----- From: AF <[email protected]> On Behalf Of Ken Hohhof Sent: Monday, January 08, 2024 12:01 PM To: 'AnimalFarm Microwave Users Group' <[email protected]> Subject: Re: [AFMUG] -48V kicking the dead horse What I can never decide on is wire colors. Especially when using red/black zipcord or tray cable. People expect red to be +, but they also expect black to be ground (except electricians who expect black to be hot and white to be neutral and green or green/yellow to be ground). And how to differentiate battery wiring from load wiring. I have not found an ideal solution other than labels. -----Original Message----- From: AF <[email protected]> On Behalf Of Bill Prince Sent: Monday, January 8, 2024 10:45 AM To: [email protected] Subject: Re: [AFMUG] -48V kicking the dead horse Yes. -48VDC means the negative side is hot, and the positive side is ground (or return). You can mix +48VDC and -48VDC if you know what you're doing. It helps a bunch if the equipment floats logic ground. You need to check to see if your equipment isolates logic from the supply voltage. Yes. Batteries can be grounded either way. They don't care. bp <part15sbs{at}gmail{dot}com> On 1/8/2024 8:25 AM, Mark - Myakka Technologies wrote: > I know we have been though this many times and I thought I understood it. > > -48VDC is the Negative side being HOT, correct? > > It is BAD to try to mix -48VDC and 48VDC > > There is no such thing as a -48V battery. A battery is a battery, correct? > > How about the ICT Platinum power supplies. They show as 48VDC, can > they be used on -48VDC equipment? > > I remember Check saying something about a way to test to see if a > piece of equipment that is Neg 48VDC is truly grounded as Neg 48VDC. > > > -- > > Thanks, > Mark mailto:[email protected] > > Myakka Communications > www.Myakka.com > > -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com
