Re: [AFMUG] DC/DC converter question
ha! +1 electricity is colorblind On Wed, Apr 10, 2019 at 6:16 PM Chuck McCown wrote: > Metallic conductor = electricity > Non conducting insulator = no electricity > > -Original Message- > From: Bill Prince > Sent: Wednesday, April 10, 2019 6:11 PM > To: af@af.afmug.com > Subject: Re: [AFMUG] DC/DC converter question > > That's NEC for household wiring. DC stuff is a whole nuther ballgame, > and there have been numerous "standards". > > bp > > > On 4/10/2019 4:10 PM, Ken Hohhof wrote: > > White=neutral, green=ground, black=hot, red=hot, blue=hot, yellow=hot, > > everything except white and green = hot. > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
Metallic conductor = electricity Non conducting insulator = no electricity -Original Message- From: Bill Prince Sent: Wednesday, April 10, 2019 6:11 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question That's NEC for household wiring. DC stuff is a whole nuther ballgame, and there have been numerous "standards". bp On 4/10/2019 4:10 PM, Ken Hohhof wrote: White=neutral, green=ground, black=hot, red=hot, blue=hot, yellow=hot, everything except white and green = hot. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
That's NEC for household wiring. DC stuff is a whole nuther ballgame, and there have been numerous "standards". bp On 4/10/2019 4:10 PM, Ken Hohhof wrote: White=neutral, green=ground, black=hot, red=hot, blue=hot, yellow=hot, everything except white and green = hot. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
White=neutral, green=ground, black=hot, red=hot, blue=hot, yellow=hot, everything except white and green = hot. -Original Message- From: AF On Behalf Of Robert Andrews Sent: Wednesday, April 10, 2019 4:20 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question And then you run into the electrician that looks at black and thinks "LOAD"... and white "NEUTRAL"... ARGGGHHH!!! On 04/10/2019 02:12 PM, ch...@wbmfg.com wrote: > This I like. > *From:* Carl Peterson > *Sent:* Wednesday, April 10, 2019 2:57 PM > *To:* AnimalFarm Microwave Users Group > *Subject:* Re: [AFMUG] DC/DC converter question My rule for -48 plants > is we label the - side -48 and the + side RET. > Then I get a hammer and beat "positive is positive and negative is > negative" into my techs heads. I also like to do Black for RET and > white for -48. > On Wed, Apr 10, 2019 at 3:49 PM Adam Moffett wrote: > > There's an IEC standard where you use +blue and -gray for a -V DC > system. > I'm sure we can find a document somewhere saying -Red for a -V DC > system. > I read a book when I was around 10 or 11 that said red was positive, > and > that stuck with me forever. > Then I learned about AC where red was a second hot when you need 2 > phases or a 3-way circuit. > > When you get multiple DC circuits in one box it seems more dangerous to > follow "standard" colors than not to. > > So I'm not gonna bag on anybody for preferring one way or another as > long as they're self consistent. Some future generation might thank > you > for putting a label somewhere that says "+" or "-". > When you get into someone else's box, Red is just a color, and you > better get your multimeter out and check. Assume makes an ass out of u > and me. Mostly me. It also blows up your equipment and trips > breakers. I guess if someone labeled a wire as "+" I'd be more likely > to believe it, but you never know who came after and thought it was > wrong and decided to "fix" it. > > I'm not trying to lecture the EE about electricity. Just shouting at > the wind I guess. > > > On 4/10/2019 4:16 PM, Ken Hohhof wrote: > > I have a couple sites where I used purple or blue for -48, but I > have spools > > of red/black zipcord that I use a lot, and I assign red to voltage > > independent of polarity, so that black is ground. Then even if I > use single > > wires, I make red voltage and black return in order to be consistent. > > > > I think it would be even more confusing to have red be ground and > black > > be-48V. Especially at mixed voltage sites that also have +24V. > > > > > > -Original Message- > > From: AF On Behalf Of Adam Moffett > > Sent: Wednesday, April 10, 2019 3:08 PM > > To: af@af.afmug.com > > Subject: Re: [AFMUG] DC/DC converter question > > > > Some people use red for negative on -48V systems. > > I've got a -48V Alvarion Wimax thingamabob with a red and black > pigtail > > coming out the back and the red is clearly labeled negative. > > > > So yeah, can't go by color unless you put that color there. > > > > > > On 4/8/2019 3:31 PM, Christopher Tyler wrote: > >> Turns out the whole shelter's bus was wired backwards when we > got it. Red > > is negative and black is positive. Not sure what the ground is > relative to, > > not sure it really matters at this point but I'll check that out > when I go > > out there later myself. > > > > -- > > AF mailing list > > AF@af.afmug.com > > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > > > > > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > -- > > Carl Peterson > > *PORT NETWORKS* > > 401 E Pratt St, Ste 2553 > > Baltimore, MD 21202 > > (410) 637-3707 > > -- > -- > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
And then you run into the electrician that looks at black and thinks "LOAD"... and white "NEUTRAL"... ARGGGHHH!!! On 04/10/2019 02:12 PM, ch...@wbmfg.com wrote: This I like. *From:* Carl Peterson *Sent:* Wednesday, April 10, 2019 2:57 PM *To:* AnimalFarm Microwave Users Group *Subject:* Re: [AFMUG] DC/DC converter question My rule for -48 plants is we label the - side -48 and the + side RET. Then I get a hammer and beat "positive is positive and negative is negative" into my techs heads. I also like to do Black for RET and white for -48. On Wed, Apr 10, 2019 at 3:49 PM Adam Moffett wrote: There's an IEC standard where you use +blue and -gray for a -V DC system. I'm sure we can find a document somewhere saying -Red for a -V DC system. I read a book when I was around 10 or 11 that said red was positive, and that stuck with me forever. Then I learned about AC where red was a second hot when you need 2 phases or a 3-way circuit. When you get multiple DC circuits in one box it seems more dangerous to follow "standard" colors than not to. So I'm not gonna bag on anybody for preferring one way or another as long as they're self consistent. Some future generation might thank you for putting a label somewhere that says "+" or "-". When you get into someone else's box, Red is just a color, and you better get your multimeter out and check. Assume makes an ass out of u and me. Mostly me. It also blows up your equipment and trips breakers. I guess if someone labeled a wire as "+" I'd be more likely to believe it, but you never know who came after and thought it was wrong and decided to "fix" it. I'm not trying to lecture the EE about electricity. Just shouting at the wind I guess. On 4/10/2019 4:16 PM, Ken Hohhof wrote: > I have a couple sites where I used purple or blue for -48, but I have spools > of red/black zipcord that I use a lot, and I assign red to voltage > independent of polarity, so that black is ground. Then even if I use single > wires, I make red voltage and black return in order to be consistent. > > I think it would be even more confusing to have red be ground and black > be-48V. Especially at mixed voltage sites that also have +24V. > > > -Original Message- > From: AF On Behalf Of Adam Moffett > Sent: Wednesday, April 10, 2019 3:08 PM > To: af@af.afmug.com > Subject: Re: [AFMUG] DC/DC converter question > > Some people use red for negative on -48V systems. > I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail > coming out the back and the red is clearly labeled negative. > > So yeah, can't go by color unless you put that color there. > > > On 4/8/2019 3:31 PM, Christopher Tyler wrote: >> Turns out the whole shelter's bus was wired backwards when we got it. Red > is negative and black is positive. Not sure what the ground is relative to, > not sure it really matters at this point but I'll check that out when I go > out there later myself. > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- Carl Peterson *PORT NETWORKS* 401 E Pratt St, Ste 2553 Baltimore, MD 21202 (410) 637-3707 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
This I like. From: Carl Peterson Sent: Wednesday, April 10, 2019 2:57 PM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] DC/DC converter question My rule for -48 plants is we label the - side -48 and the + side RET. Then I get a hammer and beat "positive is positive and negative is negative" into my techs heads. I also like to do Black for RET and white for -48. On Wed, Apr 10, 2019 at 3:49 PM Adam Moffett wrote: There's an IEC standard where you use +blue and -gray for a -V DC system. I'm sure we can find a document somewhere saying -Red for a -V DC system. I read a book when I was around 10 or 11 that said red was positive, and that stuck with me forever. Then I learned about AC where red was a second hot when you need 2 phases or a 3-way circuit. When you get multiple DC circuits in one box it seems more dangerous to follow "standard" colors than not to. So I'm not gonna bag on anybody for preferring one way or another as long as they're self consistent. Some future generation might thank you for putting a label somewhere that says "+" or "-". When you get into someone else's box, Red is just a color, and you better get your multimeter out and check. Assume makes an ass out of u and me. Mostly me. It also blows up your equipment and trips breakers. I guess if someone labeled a wire as "+" I'd be more likely to believe it, but you never know who came after and thought it was wrong and decided to "fix" it. I'm not trying to lecture the EE about electricity. Just shouting at the wind I guess. On 4/10/2019 4:16 PM, Ken Hohhof wrote: > I have a couple sites where I used purple or blue for -48, but I have spools > of red/black zipcord that I use a lot, and I assign red to voltage > independent of polarity, so that black is ground. Then even if I use single > wires, I make red voltage and black return in order to be consistent. > > I think it would be even more confusing to have red be ground and black > be-48V. Especially at mixed voltage sites that also have +24V. > > > -Original Message- > From: AF On Behalf Of Adam Moffett > Sent: Wednesday, April 10, 2019 3:08 PM > To: af@af.afmug.com > Subject: Re: [AFMUG] DC/DC converter question > > Some people use red for negative on -48V systems. > I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail > coming out the back and the red is clearly labeled negative. > > So yeah, can't go by color unless you put that color there. > > > On 4/8/2019 3:31 PM, Christopher Tyler wrote: >> Turns out the whole shelter's bus was wired backwards when we got it. Red > is negative and black is positive. Not sure what the ground is relative to, > not sure it really matters at this point but I'll check that out when I go > out there later myself. > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- Carl Peterson PORT NETWORKS 401 E Pratt St, Ste 2553 Baltimore, MD 21202 (410) 637-3707 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
My rule for -48 plants is we label the - side -48 and the + side RET. Then I get a hammer and beat "positive is positive and negative is negative" into my techs heads. I also like to do Black for RET and white for -48. On Wed, Apr 10, 2019 at 3:49 PM Adam Moffett wrote: > There's an IEC standard where you use +blue and -gray for a -V DC system. > I'm sure we can find a document somewhere saying -Red for a -V DC system. > I read a book when I was around 10 or 11 that said red was positive, and > that stuck with me forever. > Then I learned about AC where red was a second hot when you need 2 > phases or a 3-way circuit. > > When you get multiple DC circuits in one box it seems more dangerous to > follow "standard" colors than not to. > > So I'm not gonna bag on anybody for preferring one way or another as > long as they're self consistent. Some future generation might thank you > for putting a label somewhere that says "+" or "-". > When you get into someone else's box, Red is just a color, and you > better get your multimeter out and check. Assume makes an ass out of u > and me. Mostly me. It also blows up your equipment and trips > breakers. I guess if someone labeled a wire as "+" I'd be more likely > to believe it, but you never know who came after and thought it was > wrong and decided to "fix" it. > > I'm not trying to lecture the EE about electricity. Just shouting at > the wind I guess. > > > On 4/10/2019 4:16 PM, Ken Hohhof wrote: > > I have a couple sites where I used purple or blue for -48, but I have > spools > > of red/black zipcord that I use a lot, and I assign red to voltage > > independent of polarity, so that black is ground. Then even if I use > single > > wires, I make red voltage and black return in order to be consistent. > > > > I think it would be even more confusing to have red be ground and black > > be-48V. Especially at mixed voltage sites that also have +24V. > > > > > > -Original Message- > > From: AF On Behalf Of Adam Moffett > > Sent: Wednesday, April 10, 2019 3:08 PM > > To: af@af.afmug.com > > Subject: Re: [AFMUG] DC/DC converter question > > > > Some people use red for negative on -48V systems. > > I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail > > coming out the back and the red is clearly labeled negative. > > > > So yeah, can't go by color unless you put that color there. > > > > > > On 4/8/2019 3:31 PM, Christopher Tyler wrote: > >> Turns out the whole shelter's bus was wired backwards when we got it. > Red > > is negative and black is positive. Not sure what the ground is relative > to, > > not sure it really matters at this point but I'll check that out when I > go > > out there later myself. > > > > -- > > AF mailing list > > AF@af.afmug.com > > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > > > > > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- Carl Peterson *PORT NETWORKS* 401 E Pratt St, Ste 2553 Baltimore, MD 21202 (410) 637-3707 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
There's an IEC standard where you use +blue and -gray for a -V DC system. I'm sure we can find a document somewhere saying -Red for a -V DC system. I read a book when I was around 10 or 11 that said red was positive, and that stuck with me forever. Then I learned about AC where red was a second hot when you need 2 phases or a 3-way circuit. When you get multiple DC circuits in one box it seems more dangerous to follow "standard" colors than not to. So I'm not gonna bag on anybody for preferring one way or another as long as they're self consistent. Some future generation might thank you for putting a label somewhere that says "+" or "-". When you get into someone else's box, Red is just a color, and you better get your multimeter out and check. Assume makes an ass out of u and me. Mostly me. It also blows up your equipment and trips breakers. I guess if someone labeled a wire as "+" I'd be more likely to believe it, but you never know who came after and thought it was wrong and decided to "fix" it. I'm not trying to lecture the EE about electricity. Just shouting at the wind I guess. On 4/10/2019 4:16 PM, Ken Hohhof wrote: I have a couple sites where I used purple or blue for -48, but I have spools of red/black zipcord that I use a lot, and I assign red to voltage independent of polarity, so that black is ground. Then even if I use single wires, I make red voltage and black return in order to be consistent. I think it would be even more confusing to have red be ground and black be-48V. Especially at mixed voltage sites that also have +24V. -Original Message- From: AF On Behalf Of Adam Moffett Sent: Wednesday, April 10, 2019 3:08 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question Some people use red for negative on -48V systems. I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail coming out the back and the red is clearly labeled negative. So yeah, can't go by color unless you put that color there. On 4/8/2019 3:31 PM, Christopher Tyler wrote: Turns out the whole shelter's bus was wired backwards when we got it. Red is negative and black is positive. Not sure what the ground is relative to, not sure it really matters at this point but I'll check that out when I go out there later myself. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
First step switch I had to maintain used Blue for hot -48 and Black for ground/return/+48 -Original Message- From: Ken Hohhof Sent: Wednesday, April 10, 2019 2:16 PM To: 'AnimalFarm Microwave Users Group' Subject: Re: [AFMUG] DC/DC converter question I have a couple sites where I used purple or blue for -48, but I have spools of red/black zipcord that I use a lot, and I assign red to voltage independent of polarity, so that black is ground. Then even if I use single wires, I make red voltage and black return in order to be consistent. I think it would be even more confusing to have red be ground and black be-48V. Especially at mixed voltage sites that also have +24V. -Original Message- From: AF On Behalf Of Adam Moffett Sent: Wednesday, April 10, 2019 3:08 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question Some people use red for negative on -48V systems. I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail coming out the back and the red is clearly labeled negative. So yeah, can't go by color unless you put that color there. On 4/8/2019 3:31 PM, Christopher Tyler wrote: Turns out the whole shelter's bus was wired backwards when we got it. Red is negative and black is positive. Not sure what the ground is relative to, not sure it really matters at this point but I'll check that out when I go out there later myself. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
I am accustom to: Red +48 Black GND White -48 But you can never trust installations to be correct. I propose a new standard. +V purple/grey stripe gnd yellow pokadot On 4/10/19, 4:18 PM, "AF on behalf of Ken Hohhof" wrote: I have a couple sites where I used purple or blue for -48, but I have spools of red/black zipcord that I use a lot, and I assign red to voltage independent of polarity, so that black is ground. Then even if I use single wires, I make red voltage and black return in order to be consistent. I think it would be even more confusing to have red be ground and black be-48V. Especially at mixed voltage sites that also have +24V. -Original Message- From: AF On Behalf Of Adam Moffett Sent: Wednesday, April 10, 2019 3:08 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question Some people use red for negative on -48V systems. I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail coming out the back and the red is clearly labeled negative. So yeah, can't go by color unless you put that color there. On 4/8/2019 3:31 PM, Christopher Tyler wrote: > Turns out the whole shelter's bus was wired backwards when we got it. Red is negative and black is positive. Not sure what the ground is relative to, not sure it really matters at this point but I'll check that out when I go out there later myself. > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
I have a couple sites where I used purple or blue for -48, but I have spools of red/black zipcord that I use a lot, and I assign red to voltage independent of polarity, so that black is ground. Then even if I use single wires, I make red voltage and black return in order to be consistent. I think it would be even more confusing to have red be ground and black be-48V. Especially at mixed voltage sites that also have +24V. -Original Message- From: AF On Behalf Of Adam Moffett Sent: Wednesday, April 10, 2019 3:08 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question Some people use red for negative on -48V systems. I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail coming out the back and the red is clearly labeled negative. So yeah, can't go by color unless you put that color there. On 4/8/2019 3:31 PM, Christopher Tyler wrote: > Turns out the whole shelter's bus was wired backwards when we got it. Red is negative and black is positive. Not sure what the ground is relative to, not sure it really matters at this point but I'll check that out when I go out there later myself. > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
Some people use red for negative on -48V systems. I've got a -48V Alvarion Wimax thingamabob with a red and black pigtail coming out the back and the red is clearly labeled negative. So yeah, can't go by color unless you put that color there. On 4/8/2019 3:31 PM, Christopher Tyler wrote: Turns out the whole shelter's bus was wired backwards when we got it. Red is negative and black is positive. Not sure what the ground is relative to, not sure it really matters at this point but I'll check that out when I go out there later myself. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
He would bring the wax bottle ( had to be more than wax but he always called it just wax ) out at the beginning of the school year and set it on the desk and tell us about how nasty it was. I think it was this talk that kept any of the wanna be bad boys from making off with it. Yes there was a lock on the door but anyone could have picked it. Isn't lye what the "cleaner" used in Pulp Fiction? I wonder what the relative effective times would be..? i.e. how long till everything was down the drain... On 4/8/19 12:37 PM, ch...@wbmfg.com wrote: HF is certainly nothing to mess with, but still they use it in arts and crafts do etch glass. If you have ever read the safety material on it, makes you want to never be with 100' of the stuff. Is that what Walter White used in the bathtub scene? Funny thing is that sodium hydroxide (lye) heated up aqueous solution would have done a much better job. They could have rinsed the guy down the drain. -Original Message- From: Robert Sent: Monday, April 8, 2019 1:32 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question My H.S. chemistry professor, Dr. Welch ( yes that Dr. Welch ) worked for Standard Oil of California and had the patent with them for putting a small voltage on the oil pipelines throughout the US. He taught for the fun of it as his royalty money from that one patent set him up for life. He was in his 70's in 1970 so he had see some things. He also kept a vial of hydrofloric acid under his lab sink. When he passed, they found it there and brought out the bomb squad to remove it. On 4/8/19 12:17 PM, ch...@wbmfg.com wrote: -V or what I prefer to say Positive earth ground systems came from two sources. My preferred story is that buried and underground telephone cables. When they get damaged, the positive ground, negative on the telephone line cause ions in the soil to move toward the telephone line. Thus plating various metals onto the wire at the spot of the fault. If it was reversed it would move all the copper from the wire into the soil. The other story has to do with electric trollies. Same reason, track corrosion. Not sure which came first. Or really whether either is true. Chemically the telephone cable story is true. *From:* Steve Jones *Sent:* Monday, April 8, 2019 1:08 PM *To:* AnimalFarm Microwave Users Group *Subject:* Re: [AFMUG] DC/DC converter question I still have a hard time grasping the -/+ thing, im half moron and 50 percent idiot though. But am I correct that -v keeps devices from corroding as much? On Mon, Apr 8, 2019 at 1:53 PM Bill Prince wrote: +1. Just had a discussion with someone talking 12V power in RVs, and he insisted that red was negative and black was "hot". I walked away from the discussion before we resorted to fisticuffs. bp On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote: > Never trust colors. > > -Original Message- From: Christopher Tyler > Sent: Monday, April 8, 2019 11:23 AM > To: AnimalFarm Microwave Users Group > Subject: Re: [AFMUG] DC/DC converter question > > That was what I thought, thank you all for confirming. > However, with it connected red+/black-, when our tech flipped the > breaker it blew out the DC/DC converter. In fantastic order, I was told. > So I'm going to have them put a voltmeter to the wires and see what we > are getting from the power supply, maybe the output wiring is wrong. > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
HF is certainly nothing to mess with, but still they use it in arts and
crafts do etch glass.
If you have ever read the safety material on it, makes you want to never be
with 100' of the stuff.
Is that what Walter White used in the bathtub scene? Funny thing is that
sodium hydroxide (lye) heated up aqueous solution would have done a much
better job. They could have rinsed the guy down the drain.
-Original Message-
From: Robert
Sent: Monday, April 8, 2019 1:32 PM
To: af@af.afmug.com
Subject: Re: [AFMUG] DC/DC converter question
My H.S. chemistry professor, Dr. Welch ( yes that Dr. Welch ) worked for
Standard Oil of California and had the patent with them for putting a
small voltage on the oil pipelines throughout the US. He taught for
the fun of it as his royalty money from that one patent set him up for
life. He was in his 70's in 1970 so he had see some things. He also
kept a vial of hydrofloric acid under his lab sink. When he passed,
they found it there and brought out the bomb squad to remove it.
On 4/8/19 12:17 PM, ch...@wbmfg.com wrote:
-V or what I prefer to say Positive earth ground systems came from two
sources.
My preferred story is that buried and underground telephone cables. When
they get damaged, the positive ground, negative on the telephone line
cause ions in the soil to move toward the telephone line. Thus plating
various metals onto the wire at the spot of the fault. If it was reversed
it would move all the copper from the wire into the soil.
The other story has to do with electric trollies. Same reason, track
corrosion. Not sure which came first. Or really whether either is true.
Chemically the telephone cable story is true.
*From:* Steve Jones
*Sent:* Monday, April 8, 2019 1:08 PM
*To:* AnimalFarm Microwave Users Group
*Subject:* Re: [AFMUG] DC/DC converter question
I still have a hard time grasping the -/+ thing, im half moron and 50
percent idiot though. But am I correct that -v keeps devices from
corroding as much?
On Mon, Apr 8, 2019 at 1:53 PM Bill Prince wrote:
+1.
Just had a discussion with someone talking 12V power in RVs, and he
insisted that red was negative and black was "hot". I walked away from
the discussion before we resorted to fisticuffs.
bp
On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote:
> Never trust colors.
>
> -Original Message- From: Christopher Tyler
> Sent: Monday, April 8, 2019 11:23 AM
> To: AnimalFarm Microwave Users Group
> Subject: Re: [AFMUG] DC/DC converter question
>
> That was what I thought, thank you all for confirming.
> However, with it connected red+/black-, when our tech flipped the
> breaker it blew out the DC/DC converter. In fantastic order, I
was told.
> So I'm going to have them put a voltmeter to the wires and see
what we
> are getting from the power supply, maybe the output wiring is
wrong.
>
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Re: [AFMUG] DC/DC converter question
In college the professor spoke about this for about 30 seconds on the first day and said "Now, for purposes of your education, current moves from positive to negative." And we really never and an issue with it. Made the homework nice and simple without thinking about electrons or holes or anything else. The only guys that seemed to care were physics majors, vacuum tube guys and device physics/semiconductor design guys. -Original Message- From: Bill Prince Sent: Monday, April 8, 2019 1:29 PM To: af@af.afmug.com Subject: Re: [AFMUG] DC/DC converter question It probably doesn't help that Electricity is actually electron flow, which comes from the negative terminal. It all would have been so much easier if they had called electrons positive, so that the actual flow matched the theoretical flow. Instead, some probably think of electricity flowing from the positive terminal, when in fact it is the sink, not the source. bp On 4/8/2019 10:23 AM, Christopher Tyler wrote: That was what I thought, thank you all for confirming. However, with it connected red+/black-, when our tech flipped the breaker it blew out the DC/DC converter. In fantastic order, I was told. So I'm going to have them put a voltmeter to the wires and see what we are getting from the power supply, maybe the output wiring is wrong. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
My H.S. chemistry professor, Dr. Welch ( yes that Dr. Welch ) worked for
Standard Oil of California and had the patent with them for putting a
small voltage on the oil pipelines throughout the US. He taught for
the fun of it as his royalty money from that one patent set him up for
life. He was in his 70's in 1970 so he had see some things. He also
kept a vial of hydrofloric acid under his lab sink. When he passed,
they found it there and brought out the bomb squad to remove it.
On 4/8/19 12:17 PM, ch...@wbmfg.com wrote:
-V or what I prefer to say Positive earth ground systems came from two
sources.
My preferred story is that buried and underground telephone cables. When
they get damaged, the positive ground, negative on the telephone line
cause ions in the soil to move toward the telephone line. Thus plating
various metals onto the wire at the spot of the fault. If it was
reversed it would move all the copper from the wire into the soil.
The other story has to do with electric trollies. Same reason, track
corrosion. Not sure which came first. Or really whether either is
true. Chemically the telephone cable story is true.
*From:* Steve Jones
*Sent:* Monday, April 8, 2019 1:08 PM
*To:* AnimalFarm Microwave Users Group
*Subject:* Re: [AFMUG] DC/DC converter question
I still have a hard time grasping the -/+ thing, im half moron and 50
percent idiot though. But am I correct that -v keeps devices from
corroding as much?
On Mon, Apr 8, 2019 at 1:53 PM Bill Prince wrote:
+1.
Just had a discussion with someone talking 12V power in RVs, and he
insisted that red was negative and black was "hot". I walked away from
the discussion before we resorted to fisticuffs.
bp
On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote:
> Never trust colors.
>
> -Original Message- From: Christopher Tyler
> Sent: Monday, April 8, 2019 11:23 AM
> To: AnimalFarm Microwave Users Group
> Subject: Re: [AFMUG] DC/DC converter question
>
> That was what I thought, thank you all for confirming.
> However, with it connected red+/black-, when our tech flipped the
> breaker it blew out the DC/DC converter. In fantastic order, I
was told.
> So I'm going to have them put a voltmeter to the wires and see
what we
> are getting from the power supply, maybe the output wiring is wrong.
>
--
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Re: [AFMUG] DC/DC converter question
Turns out the whole shelter's bus was wired backwards when we got it. Red is negative and black is positive. Not sure what the ground is relative to, not sure it really matters at this point but I'll check that out when I go out there later myself. -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 - Original Message - From: "Robert" To: af@af.afmug.com Sent: Monday, April 8, 2019 2:25:45 PM Subject: Re: [AFMUG] DC/DC converter question What Polarity do they apply to pipelines to get iron to stick to them instead of eroding away? On 4/8/19 12:08 PM, Steve Jones wrote: > I still have a hard time grasping the -/+ thing, im half moron and 50 > percent idiot though. But am I correct that -v keeps devices from > corroding as much? > > On Mon, Apr 8, 2019 at 1:53 PM Bill Prince <mailto:part15...@gmail.com>> wrote: > > +1. > > Just had a discussion with someone talking 12V power in RVs, and he > insisted that red was negative and black was "hot". I walked away from > the discussion before we resorted to fisticuffs. > > > bp > > > On 4/8/2019 10:35 AM, ch...@wbmfg.com <mailto:ch...@wbmfg.com> wrote: > > Never trust colors. > > > > -Original Message- From: Christopher Tyler > > Sent: Monday, April 8, 2019 11:23 AM > > To: AnimalFarm Microwave Users Group > > Subject: Re: [AFMUG] DC/DC converter question > > > > That was what I thought, thank you all for confirming. > > However, with it connected red+/black-, when our tech flipped the > > breaker it blew out the DC/DC converter. In fantastic order, I > was told. > > So I'm going to have them put a voltmeter to the wires and see > what we > > are getting from the power supply, maybe the output wiring is wrong. > > > > -- > AF mailing list > AF@af.afmug.com <mailto:AF@af.afmug.com> > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
It probably doesn't help that Electricity is actually electron flow, which comes from the negative terminal. It all would have been so much easier if they had called electrons positive, so that the actual flow matched the theoretical flow. Instead, some probably think of electricity flowing from the positive terminal, when in fact it is the sink, not the source. bp On 4/8/2019 10:23 AM, Christopher Tyler wrote: That was what I thought, thank you all for confirming. However, with it connected red+/black-, when our tech flipped the breaker it blew out the DC/DC converter. In fantastic order, I was told. So I'm going to have them put a voltmeter to the wires and see what we are getting from the power supply, maybe the output wiring is wrong. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
They call it cathodic protection. They put negative on the pipe and + on
the sacrificial anode.
-Original Message-
From: Robert
Sent: Monday, April 8, 2019 1:25 PM
To: af@af.afmug.com
Subject: Re: [AFMUG] DC/DC converter question
What Polarity do they apply to pipelines to get iron to stick to them
instead of eroding away?
On 4/8/19 12:08 PM, Steve Jones wrote:
I still have a hard time grasping the -/+ thing, im half moron and 50
percent idiot though. But am I correct that -v keeps devices from
corroding as much?
On Mon, Apr 8, 2019 at 1:53 PM Bill Prince <mailto:part15...@gmail.com>> wrote:
+1.
Just had a discussion with someone talking 12V power in RVs, and he
insisted that red was negative and black was "hot". I walked away from
the discussion before we resorted to fisticuffs.
bp
On 4/8/2019 10:35 AM, ch...@wbmfg.com <mailto:ch...@wbmfg.com> wrote:
> Never trust colors.
>
> -Original Message- From: Christopher Tyler
> Sent: Monday, April 8, 2019 11:23 AM
> To: AnimalFarm Microwave Users Group
> Subject: Re: [AFMUG] DC/DC converter question
>
> That was what I thought, thank you all for confirming.
> However, with it connected red+/black-, when our tech flipped the
> breaker it blew out the DC/DC converter. In fantastic order, I
was told.
> So I'm going to have them put a voltmeter to the wires and see
what we
> are getting from the power supply, maybe the output wiring is
wrong.
>
--
AF mailing list
AF@af.afmug.com <mailto:AF@af.afmug.com>
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
--
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AF@af.afmug.com
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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AF@af.afmug.com
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Re: [AFMUG] DC/DC converter question
What Polarity do they apply to pipelines to get iron to stick to them
instead of eroding away?
On 4/8/19 12:08 PM, Steve Jones wrote:
I still have a hard time grasping the -/+ thing, im half moron and 50
percent idiot though. But am I correct that -v keeps devices from
corroding as much?
On Mon, Apr 8, 2019 at 1:53 PM Bill Prince <mailto:part15...@gmail.com>> wrote:
+1.
Just had a discussion with someone talking 12V power in RVs, and he
insisted that red was negative and black was "hot". I walked away from
the discussion before we resorted to fisticuffs.
bp
On 4/8/2019 10:35 AM, ch...@wbmfg.com <mailto:ch...@wbmfg.com> wrote:
> Never trust colors.
>
> -Original Message- From: Christopher Tyler
> Sent: Monday, April 8, 2019 11:23 AM
> To: AnimalFarm Microwave Users Group
> Subject: Re: [AFMUG] DC/DC converter question
>
> That was what I thought, thank you all for confirming.
> However, with it connected red+/black-, when our tech flipped the
> breaker it blew out the DC/DC converter. In fantastic order, I
was told.
> So I'm going to have them put a voltmeter to the wires and see
what we
> are getting from the power supply, maybe the output wiring is wrong.
>
--
AF mailing list
AF@af.afmug.com <mailto:AF@af.afmug.com>
http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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AF@af.afmug.com
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Re: [AFMUG] DC/DC converter question
Oh that would be a fun thing to watch... Ok so you are so positive (pun intended) Here, let's hook this ( whatever you don't care about that is polarity sensitive ) up... On 4/8/19 11:51 AM, Bill Prince wrote: +1. Just had a discussion with someone talking 12V power in RVs, and he insisted that red was negative and black was "hot". I walked away from the discussion before we resorted to fisticuffs. bp On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote: Never trust colors. -Original Message- From: Christopher Tyler Sent: Monday, April 8, 2019 11:23 AM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] DC/DC converter question That was what I thought, thank you all for confirming. However, with it connected red+/black-, when our tech flipped the breaker it blew out the DC/DC converter. In fantastic order, I was told. So I'm going to have them put a voltmeter to the wires and see what we are getting from the power supply, maybe the output wiring is wrong. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
-V or what I prefer to say Positive earth ground systems came from two sources. My preferred story is that buried and underground telephone cables. When they get damaged, the positive ground, negative on the telephone line cause ions in the soil to move toward the telephone line. Thus plating various metals onto the wire at the spot of the fault. If it was reversed it would move all the copper from the wire into the soil. The other story has to do with electric trollies. Same reason, track corrosion. Not sure which came first. Or really whether either is true. Chemically the telephone cable story is true. From: Steve Jones Sent: Monday, April 8, 2019 1:08 PM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] DC/DC converter question I still have a hard time grasping the -/+ thing, im half moron and 50 percent idiot though. But am I correct that -v keeps devices from corroding as much? On Mon, Apr 8, 2019 at 1:53 PM Bill Prince wrote: +1. Just had a discussion with someone talking 12V power in RVs, and he insisted that red was negative and black was "hot". I walked away from the discussion before we resorted to fisticuffs. bp On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote: > Never trust colors. > > -Original Message- From: Christopher Tyler > Sent: Monday, April 8, 2019 11:23 AM > To: AnimalFarm Microwave Users Group > Subject: Re: [AFMUG] DC/DC converter question > > That was what I thought, thank you all for confirming. > However, with it connected red+/black-, when our tech flipped the > breaker it blew out the DC/DC converter. In fantastic order, I was told. > So I'm going to have them put a voltmeter to the wires and see what we > are getting from the power supply, maybe the output wiring is wrong. > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
I still have a hard time grasping the -/+ thing, im half moron and 50 percent idiot though. But am I correct that -v keeps devices from corroding as much? On Mon, Apr 8, 2019 at 1:53 PM Bill Prince wrote: > +1. > > Just had a discussion with someone talking 12V power in RVs, and he > insisted that red was negative and black was "hot". I walked away from > the discussion before we resorted to fisticuffs. > > > bp > > > On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote: > > Never trust colors. > > > > -Original Message- From: Christopher Tyler > > Sent: Monday, April 8, 2019 11:23 AM > > To: AnimalFarm Microwave Users Group > > Subject: Re: [AFMUG] DC/DC converter question > > > > That was what I thought, thank you all for confirming. > > However, with it connected red+/black-, when our tech flipped the > > breaker it blew out the DC/DC converter. In fantastic order, I was told. > > So I'm going to have them put a voltmeter to the wires and see what we > > are getting from the power supply, maybe the output wiring is wrong. > > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
+1. Just had a discussion with someone talking 12V power in RVs, and he insisted that red was negative and black was "hot". I walked away from the discussion before we resorted to fisticuffs. bp On 4/8/2019 10:35 AM, ch...@wbmfg.com wrote: Never trust colors. -Original Message- From: Christopher Tyler Sent: Monday, April 8, 2019 11:23 AM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] DC/DC converter question That was what I thought, thank you all for confirming. However, with it connected red+/black-, when our tech flipped the breaker it blew out the DC/DC converter. In fantastic order, I was told. So I'm going to have them put a voltmeter to the wires and see what we are getting from the power supply, maybe the output wiring is wrong. -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
Never trust colors. -Original Message- From: Christopher Tyler Sent: Monday, April 8, 2019 11:23 AM To: AnimalFarm Microwave Users Group Subject: Re: [AFMUG] DC/DC converter question That was what I thought, thank you all for confirming. However, with it connected red+/black-, when our tech flipped the breaker it blew out the DC/DC converter. In fantastic order, I was told. So I'm going to have them put a voltmeter to the wires and see what we are getting from the power supply, maybe the output wiring is wrong. -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 - Original Message - From: ch...@wbmfg.com To: "AnimalFarm Microwave Users Group" Sent: Monday, April 8, 2019 11:59:47 AM Subject: Re: [AFMUG] DC/DC converter question What Ken said. Positive is always positive. Neg is always neg. 48 volts is 48 volts. If someone wants to say a load or source is -48 or +48 it just means the opposite polarity is tied to earth or chassis ground. If they say a load needs -48, it could mean that the load has the positive power wire also connected to the case. If a source says it is a -48 source, it could mean that the source has the positive lead connected to ground. You can always test a source. Ground to the wire. If you measure 48 volts between ground and one of the power wires, then it is referenced to ground. If you are on the positive wire to ground and you see 48 volts, then it is a neg ground system. If you are on the neg wire to ground and you see 48 volts then you are on a positive ground system. Positive Ground System == -48 or whatever volt system Neg Ground System == +48 or whatever BUT many sources and loads are floating where neither power lead is connected to chassis/earth/ground Sometimes they will call those 48 VDC system. But sometimes they will call them a +48 VDC system when really it is simply a 48 VDC system. Anytime -48 is printed on something, time to take it seriously. They probably mean it. -Original Message- From: Christopher Tyler Sent: Monday, April 8, 2019 9:54 AM To: AnimalFarm Microwave Users Group Subject: [AFMUG] DC/DC converter question I have a Meanwell SD-350C-24 DC/DC converter for +48v in to +24v out. I just learned that our DC plant at this site is -48vdc. I'm assuming that I can't just plug it in backwards. But we've never had to deal with -48vdc before, am I wrong in this assumption? -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
That was what I thought, thank you all for confirming. However, with it connected red+/black-, when our tech flipped the breaker it blew out the DC/DC converter. In fantastic order, I was told. So I'm going to have them put a voltmeter to the wires and see what we are getting from the power supply, maybe the output wiring is wrong. -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 - Original Message - From: ch...@wbmfg.com To: "AnimalFarm Microwave Users Group" Sent: Monday, April 8, 2019 11:59:47 AM Subject: Re: [AFMUG] DC/DC converter question What Ken said. Positive is always positive. Neg is always neg. 48 volts is 48 volts. If someone wants to say a load or source is -48 or +48 it just means the opposite polarity is tied to earth or chassis ground. If they say a load needs -48, it could mean that the load has the positive power wire also connected to the case. If a source says it is a -48 source, it could mean that the source has the positive lead connected to ground. You can always test a source. Ground to the wire. If you measure 48 volts between ground and one of the power wires, then it is referenced to ground. If you are on the positive wire to ground and you see 48 volts, then it is a neg ground system. If you are on the neg wire to ground and you see 48 volts then you are on a positive ground system. Positive Ground System == -48 or whatever volt system Neg Ground System == +48 or whatever BUT many sources and loads are floating where neither power lead is connected to chassis/earth/ground Sometimes they will call those 48 VDC system. But sometimes they will call them a +48 VDC system when really it is simply a 48 VDC system. Anytime -48 is printed on something, time to take it seriously. They probably mean it. -Original Message- From: Christopher Tyler Sent: Monday, April 8, 2019 9:54 AM To: AnimalFarm Microwave Users Group Subject: [AFMUG] DC/DC converter question I have a Meanwell SD-350C-24 DC/DC converter for +48v in to +24v out. I just learned that our DC plant at this site is -48vdc. I'm assuming that I can't just plug it in backwards. But we've never had to deal with -48vdc before, am I wrong in this assumption? -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
What Ken said. Positive is always positive. Neg is always neg. 48 volts is 48 volts. If someone wants to say a load or source is -48 or +48 it just means the opposite polarity is tied to earth or chassis ground. If they say a load needs -48, it could mean that the load has the positive power wire also connected to the case. If a source says it is a -48 source, it could mean that the source has the positive lead connected to ground. You can always test a source. Ground to the wire. If you measure 48 volts between ground and one of the power wires, then it is referenced to ground. If you are on the positive wire to ground and you see 48 volts, then it is a neg ground system. If you are on the neg wire to ground and you see 48 volts then you are on a positive ground system. Positive Ground System == -48 or whatever volt system Neg Ground System == +48 or whatever BUT many sources and loads are floating where neither power lead is connected to chassis/earth/ground Sometimes they will call those 48 VDC system. But sometimes they will call them a +48 VDC system when really it is simply a 48 VDC system. Anytime -48 is printed on something, time to take it seriously. They probably mean it. -Original Message- From: Christopher Tyler Sent: Monday, April 8, 2019 9:54 AM To: AnimalFarm Microwave Users Group Subject: [AFMUG] DC/DC converter question I have a Meanwell SD-350C-24 DC/DC converter for +48v in to +24v out. I just learned that our DC plant at this site is -48vdc. I'm assuming that I can't just plug it in backwards. But we've never had to deal with -48vdc before, am I wrong in this assumption? -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
Re: [AFMUG] DC/DC converter question
I don't see anything in the spec sheet that indicates the input and output care about which side you connect to ground. I know I have used the RSD series to go from 24 to 48 and the input and output were isolated from each other and floating with respect to ground. I suspect the SD series is also. Don't plug it in "backwards". + should always go to +, and - should always go to -. When you say +48 or -48 or +24, that refers to which side is connected to ground. I have never used that exact model, I believe the RSD series is preferred because it won't lock up due to load inrush current. Also there are more options for turning 48V into 24V than the other way around. -Original Message- From: AF On Behalf Of Christopher Tyler Sent: Monday, April 8, 2019 10:54 AM To: AnimalFarm Microwave Users Group Subject: [AFMUG] DC/DC converter question I have a Meanwell SD-350C-24 DC/DC converter for +48v in to +24v out. I just learned that our DC plant at this site is -48vdc. I'm assuming that I can't just plug it in backwards. But we've never had to deal with -48vdc before, am I wrong in this assumption? -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
[AFMUG] DC/DC converter question
I have a Meanwell SD-350C-24 DC/DC converter for +48v in to +24v out. I just learned that our DC plant at this site is -48vdc. I'm assuming that I can't just plug it in backwards. But we've never had to deal with -48vdc before, am I wrong in this assumption? -- Christopher Tyler MTCRE/MTCNA/MTCTCE/MTCWE Total Highspeed Internet Services 417.851.1107 ext 9002 -- AF mailing list AF@af.afmug.com http://af.afmug.com/mailman/listinfo/af_af.afmug.com
