3 Phase Single Phase Wiring

[nehog]

I live east of the Mississippi, and have dealt with :

345,000
138,000
69,000
34,500
13,800
12,470/7200
6600
4160
2400
480/277
240/120
208/120

But I've never heard of 240/416.

Actually only used by the military, IIRC... It is one of the settings on my generator set.

For anyone willing to search for it, I did post an explanation why 120/208 exists with a graph showing why it is not 120/240. I remember that a few did complement the post saying it cleared up why it was that way.

BTW, with a wye configuration, you get two voltages with a neutral. With a pure delta, you get one voltage with no neutral. With a high-leg delta you get two voltages, with a neutral, but the neutral's relationship is to only one phase, not all three. A high-leg delta is not (usually) practical for a generator set as it is inherently unbalanced. The power company can do it because they typically have multiple customers using the configuration across the different phases.

 

[Nelson58]

I have been researching 3 phase for awhile and I my head is spinning. I don't have the electrical know how to totally understand it so I want to just try and get the basics down. I know that some tools / equipment have to have 3 phase and some have it as an option. I know that you either need to get 3 phase from the street or have a converter. Correct me if I am wrong on any of this.

What I want to know, how does the wiring differ? Budgets being budgets I will end up doing all of my wiring well before having all the tools I will be using and won't really know where I want them. Most likely I would end up moving things around even if I did know where I want them the first time. So would the same wiring be used if I was doing a 3 phase outlet or a 220 outlet? Idea being I can run some wiring to different locations and then wire the outlet for the tool as needed.

Hope that made sense.

In the exact same position as you are Schwalby. I want to power up the machines in my shop. i have a lathe, 2 mills and a grinder, all of which are 3 phase motored, and want to use VFDs (variable frequency drives) to allow them to accept single phase power to power up their 3-phase motors.

I am going to have a licensed electrician install the 220 single phase outlets for me. I will have him upgrade my basement panel if need be, (have only 100 amp), or, if necessary install a sub-panel. I bought a couple of books on 3 phase motors, but it still is kinda remote to me.

This section has some good threads on panel wiring.


Nelson

 

[Grinder Bill]

What I want to know, how does the wiring differ?

Back to the original question; the color of the conductors is the only difference. Single phase is Red/Black/White and 3 phase is Red/Black/Blue.

I ran 3 phase teck cable to my last shop, but the feed was only single phase; the inspector was ok with wraping the exposed Blue ends with white tape to indicate neutral.

 

[mrb]

Back to the original question; the color of the conductors is the only difference. Single phase is Red/Black/White and 3 phase is Red/Black/Blue.

I ran 3 phase teck cable to my last shop, but the feed was only single phase; the inspector was ok with wraping the exposed Blue ends with white tape to indicate neutral.

uh there's a heck of alot more to it than the color of the wires.

 

[Grinder Bill]

uh there's a heck of alot more to it than the color of the wires.

Not from the pole to the panel.

 

[mrb]

Not from the pole to the panel.

delta or wye?

 

[Grinder Bill]

Not a consideration yet; the OP has yet to decide on whether he's going 1 or 3 phase.

Commit to single phase but wire the shop for 3 phase and use white phase tape on the blue conductor. Panel and disconnects can be swapped out later to accomodate an upgrade to 3 phase. And remove the white tape...

 

[mrb]

Not a consideration yet; the OP has yet to decide on whether he's going 1 or 3 phase.

Commit to single phase but wire the shop for 3 phase and use white phase tape on the blue conductor. Panel and disconnects can be swapped out later to accomodate an upgrade to 3 phase. And remove the white tape...

youre missing the point. there are three possible 3ph service types, only one of which would be available to him. 120/208 WYE is going to need 4 wires not three. 240 Delta is three hots, but you cant get 120v from that (without a transformer which brings up a bunch more issues), or 240 center tapped delta which does get you 120v but also needs 4 wires from the pole.

he needs to decide what he's going to install now and install it. If that is single phase and he may add 3ph later then add the 3ph later. Any attempt to 'wire the shop for 3 phase now' will most likely not result in much (if any) savings later.

 

[foolishpride]

youre missing the point. there are three possible 3ph service types, only one of which would be available to him. 120/208 WYE is going to need 4 wires not three. 240 Delta is three hots, but you cant get 120v from that (without a transformer which brings up a bunch more issues), or 240 center tapped delta which does get you 120v but also needs 4 wires from the pole.

he needs to decide what he's going to install now and install it. If that is single phase and he may add 3ph later then add the 3ph later. Any attempt to 'wire the shop for 3 phase now' will most likely not result in much (if any) savings later.

MRB, you're making it way too complicated. If you got the correct wire colors, you're good to go!

No, seriously. Lately, I've been reading the Lighting & Electrical section, and I've got to say that some of these people that are giving advice about electrical problems and solutions, have no business doing it. I can tell they know just enough about electrical to be dangerous. If you don't know what you're talking about, please don't give advice. Or please say "I'm not sure, but I think it's this way or that way".

 

[kursplat]

I live east of the Mississippi, and have dealt with :

345,000
138,000
34,500
7200
4160
2400
480/277
240/120
208/120

we have all those along with straight 480 and straight 240 power. no neutral.
we also have 500,000 ac and 1,000,000 dc transmission lines here in l.a.

MRB, you're making it way too complicated. If you got the correct wire colors, you're good to go!

at first i thought WTF...but then i noticed the
which made me think "ya, that makes it easy"
easyer still is add the colored tape after you pull the wire and land it. that way you always get r/w/b left to right

 

[Norcal]

Aw, you forgot 240/416!

It's 415/240, BTW & it's variants (380/220, & 400/230V) are used in most of the world, the current standard is 400/230V & it is also 50 hertz.....

Edit: I am at relatives in Germany ATM & where I am staying has a 400V 3Ø circuit for the range....