But what about Low voltage cable... Is smooth hot or cold or ridged hot
or cold? So many choices... LOL..
On 1/8/24 9:39 AM, dmmoff...@gmail.com wrote:
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
480 is 277 to ground/neutral and you can find lots of 277 stuff. Even 277-120
control transformers are pretty common. I would not be surprised to see Mean
Wells and Tracos having models that will take up to 277.
Best Regards,
Chuck McCown
McCown Technology Corporation
8401 N Commerce Dr
We run into this at farms and grain elevators that often have 240 or 480
3-phase. We are on the grain leg at one farm where there is only the 3 legs no
neutral. We checked with Phoenix Contact and the power supply we used can
accept L1 and L2 on the terminals labeled L and N (actually a Trio
Another option, 208 Y but 32 volt boost transformers on devices that need 240.
Have done that before too. I always consider boost and buck a slick trick.
From: Chuck McCown via AF
Sent: Monday, January 8, 2024 2:43 PM
To: AnimalFarm Microwave Users Group
Cc: ch...@go-mtc.com
Subject: Re:
You a few choices for 3 phase mixed with 120 single phase. Stinger center
tapped winding on a Delta lets you have single phase 120/240 between two legs
of the delta.
But this also means you have 240 three phase all the way around where many 3
phase loads are nominally spec’d at 208.
> On Jan 8, 2024, at 1:54 PM, Ken Hohhof wrote:
>
> What I always have a hard time wrapping my head around is 240/120/208 wild
> leg delta.
>
I don’t think that one is hard to understand, other then the ‘why the hell did
someone center tap a delta let anyway?Ok, I have designed
My rule for DC plants is BLACK == Ground Referenced side.
On Mon, Jan 8, 2024 at 11:02 AM Ken Hohhof wrote:
> 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
Have to have a chalk board to show the wild leg thing. I got my 3 phase down
pretty cold now.
Had an electrician wire up a receptacle to the wild leg once.
Blew up a transformer. That was my first exposure to a wild leg.
From: Ken Hohhof
Sent: Monday, January 8, 2024 11:54 AM
To:
I would think many of us have both 24V and 48V in the same rack or cabinet. We
started out 24V, then mixed, now able to do most sites all 48V, but lots of
mixed 24 and 48 out there. I think of -48 as just another voltage to keep
straight. If I power a radio or router with 48-56 volts that is
The ICT shelves come in both +48v and -48v flavors. Usually the positive
version has a P on the end of the model. An ICT-2U4 would be negative, and
an ICT-2U4P is positive. You can mix both -48 and +48 loads at one site,
but you need an isolated DC-DC converter such as a Meanwell RSD-500C-48.
The issue is if the power supply or any of the equipment connected to it has
positive tied to ground and then you take another device with negative tied
to ground and put that on the same power supply. Then you have + and - of
the power supply dead shorted through the ground connections and
I would be more than happy with that scheme.
Look up at a fuse or CB panel, see red and blue and you immediately know
what you are working with.
-Original Message-
From: dmmoff...@gmail.com
Sent: Monday, January 8, 2024 10:39 AM
To: 'AnimalFarm Microwave Users Group'
Subject: Re:
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
I literally smoked a digital COE switch due to this one time.
I have seen Blue for hot and Red for return -48
I have seen Blue for hot and Black for return -48
Black for hot and Red for return in a -48 system.
Which would make that one Red+ and Black - but positive ground.
Red for hot and
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
I mixed + and - 48 in a off grid solar system. I had one battery bank with
the positive to the common point/ ground. The other battery bank was
negative to the common point. From one battery to the other it was 96 volts
when went to the load.
But I had two 48 volt solar systems and charge
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.
Most AC/DC and DC/DC power supplies have input/output isolation and neither
side of the output grounded unless/until you ground one side. If you ground
the - side, then it's referred to as +48V. If you ground the + side, then
it's -48V.
Fancier equipment with stuff like management interfaces
>It is BAD to try to mix -48VDC and 48VDC
Very
>There is no such thing as a -48V battery. A battery is a battery, correct?
Correct. You still wire + to + and - to -
>How about the ICT Platinum power supplies. They show as 48VDC, can they
be used on -48VDC equipment?
Pretty confident, this
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
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