Electrical question

[CobyRupert]

So on a Y, the centre is neutral? And at 600, any outer point to neutral is 347?

I built a 600 rotary converter wired in Delta and wondered how to get a ground reference?

"So on a Y, the centre is neutral?" Yes, (but in U.S. it's the center that is neutral. :laughing: -Canadian joke)).

"And at 600, any outer point to neutral is 347?" - On a 600V, 3 phase (wye) system (3 phase, 4 wire), the phase-to neutral voltage will be 347V. I think this is what your asking.

"I built a 600 rotary converter wired in Delta and wondered how to get a ground reference? " It's important to know the difference between ground and neutral. You cant get a neutral reference from a delta. On a delta system, when you talk about 600 volts, that's between phases, period. You can't speak of, or reference, this voltage to the voltage you would measure to "ground" (earth) if you had a voltmeter between the phase and earth. This voltage could be anything (600 volts, 50 volts, 300 volts, etc..). This is because it's not like a "Y" wye connection where the center neutral is grounded to earth.

Why do you need a ground reference?

 

[Industrial Toys]

The more I think about it. The more confused I get. Not a big fan of 600 volts. So the thought of not having a system where if a live 600 volt leg touches a (grounded) metal cabinet, or conduit and a breaker trips, troubled me.

 

[joeu235]

If code requires 10 gauge and you are certain you are right (since without details we have no idea), what was the purpose of this thread?

I was confused thinking about how a load draws half the amps when its converted from 120 to 240.

 

[LD1]

Loads as most think of them are typically measured in watts.

And doubling the voltage does indeed cut the amps in half.

A 100w 120v light bulb will draw twice the amps as a 100w 240v bulb.

A 2 hp 120v motor will draw twice the amps as a 2hp 240v motor.

 

[mbohuntr]

I am getting a notion that the difference between short circuit protection and thermal protection is not well understood by most members here.
I would assume that googling Canadian electrical code and table D16 may show the chart. A picture is worth a thousand words .

I am quite aware of thermal overloads, They are listed as a 49 type device, and we test them frequently. I was fishing because there is a world of difference between a 240v table saw, and a motor on a 480-600V MCC with overload protection. I.E..."HEATERS"


I believe the OP was talking about residential single phase wiring. Does the 240V 100 amp breaker circuit you describe offer the homeowner thermal protection? Or should you fall back to the "Size the conductor to the FLA expected, and the breaker to protect the conductor?

Not trying to pick a fight Buickanddeere, but I believe your info is more for a business than a homeowner.

 

[mbohuntr]

I was confused thinking about how a load draws half the amps when its converted from 120 to 240.

Watts is a unit of measurement that in it's simplest form equals Volts x Amps... 2000 watts / 240 volts = 8.33 amps used. 2000 watts/120 volts = 16.67amps.

Less amps = lower electric bill..

 

[mbohuntr]

The more I think about it. The more confused I get. Not a big fan of 600 volts. So the thought of not having a system where if a live 600 volt leg touches a (grounded) metal cabinet, or conduit and a breaker trips, troubled me.

If a conductor touches the inside of the conduit, it will trip. Those systems are required to be grounded and the breakers have "instatrip" functions where the huge momentary current will trip the breaker in thousandths of a second. A lot different than your house breakers which are mostly thermal.

 

[buickanddeere]

The more I think about it. The more confused I get. Not a big fan of 600 volts. So the thought of not having a system where if a live 600 volt leg touches a (grounded) metal cabinet, or conduit and a breaker trips, troubled me.

Why any difference if a live line grounds out on 120,240,277 or 347 ? Ever see how many sparks a 12V battery can throw ?

 

[prichard]

If a conductor touches the inside of the conduit, it will trip. Those systems are required to be grounded and the breakers have "instatrip" functions where the huge momentary current will trip the breaker in thousandths of a second. A lot different than your house breakers which are mostly thermal.

Not true. His system is ungrounded. Without a ground there is no current flow to this metal surface. Any one leg can be grounded, but only 1. If you ground 1 leg them a second touches you get instant trip.

 

[mbohuntr]

Not true. His system is ungrounded. Without a ground there is no current flow to this metal surface. Any one leg can be grounded, but only 1. If you ground 1 leg them a second touches you get instant trip.

Do you have a link to that? I have never heard that, and every conduit and frame we have is house grounded. We even have floating "isolated" transformer grounding on the main gens. I would love to read up on that. Thanks