gingle phase from three phase
- Thread starter frank
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BAHTAH
Senior Member
- Location
- United States
Re: gingle phase from three phase
It should be fine. It would be the same as using a closed delta 120/240v 3ph4w and using 240v single-phase. You are just looking for 240V single-phase.
It should be fine. It would be the same as using a closed delta 120/240v 3ph4w and using 240v single-phase. You are just looking for 240V single-phase.
scott thompson
Senior Member
- Location
- Anaheim, California
Re: gingle phase from three phase
It is still being connected across a single coil, therefore the Current flows one direction for ? the cycle, then flows the opposite direction for ? cycle.
Same current, just bounced back and forth! (like a See-Saw).
120? Lead/Lag comes into play when driving currents from the 3? terminations into a 3? load - such as a Delta Connected Induction Motor.
Any L-L connected load will only see a Single Phase Current, since it's being driven from only one Single Transformer coil.
Example:
Let's say at the time of connection, the magnetic flux in the core is setup as to begin creating a current flow + EMF in the coil, which flows in a forward (outward) direction at Terminal X1. X1 will have a Potential Difference as viewed by the opposite end of the coil, Terminal X2.
The current will flow from X1, through the Motor's winding(s), dissipate the coupled True Power into the windings, and flow into the X2 side. The current flows back into the coil, then through the coil, just as it did in the motor windings.
During this first Half Cycle, the levels (amplitudes) of the flowing current and the Voltage pushing it, rise from a stand-still zero level to a "PEAK" level, then return to a stand-still zero level once again.
On the second half of the cycle, that same current (derived from the same flux in the core, but is now flowing the opposite direction) runs from the X2 Terminal, through the Motor's windings, Dissipate True Power in the windings / rotor (via Inductive coupled situation
..), and into the X1 Terminal side of the coil.
Once again, the amplitudes of I and E rise to a Peak level, then fall back to zero.
The current that flows through the Motor's windings also flows through the Secondary coil.
Figure a DC circuit's flow characteristics for each ? cycle (and think of the waves as square waves instead of clean sine waves). Current will flow through the Motor's windings and through the power supply at the same time, in a circular fashion.
For an example frequency of 1Hz, connect the leads so X1 = "+" and X2 = "-".
Let this run for 0.5 seconds.
At 0.5 seconds, remove the leads, then reconnect in opposite fashion (X1 = "-", X2 = "+"). Continue doing this over and over and over.....
What has been described here is the way your 1? Induction Motor will see currents from either a 1? or 3? Transformer.
Scott35
Nahh, there's no difference connecting it to a 1? supply or a 3? supply.
It is still being connected across a single coil, therefore the Current flows one direction for ? the cycle, then flows the opposite direction for ? cycle.
Same current, just bounced back and forth! (like a See-Saw).
120? Lead/Lag comes into play when driving currents from the 3? terminations into a 3? load - such as a Delta Connected Induction Motor.
Any L-L connected load will only see a Single Phase Current, since it's being driven from only one Single Transformer coil.
Example:
Let's say at the time of connection, the magnetic flux in the core is setup as to begin creating a current flow + EMF in the coil, which flows in a forward (outward) direction at Terminal X1. X1 will have a Potential Difference as viewed by the opposite end of the coil, Terminal X2.
The current will flow from X1, through the Motor's winding(s), dissipate the coupled True Power into the windings, and flow into the X2 side. The current flows back into the coil, then through the coil, just as it did in the motor windings.
During this first Half Cycle, the levels (amplitudes) of the flowing current and the Voltage pushing it, rise from a stand-still zero level to a "PEAK" level, then return to a stand-still zero level once again.
On the second half of the cycle, that same current (derived from the same flux in the core, but is now flowing the opposite direction) runs from the X2 Terminal, through the Motor's windings, Dissipate True Power in the windings / rotor (via Inductive coupled situation
..), and into the X1 Terminal side of the coil.Once again, the amplitudes of I and E rise to a Peak level, then fall back to zero.
The current that flows through the Motor's windings also flows through the Secondary coil.
Figure a DC circuit's flow characteristics for each ? cycle (and think of the waves as square waves instead of clean sine waves). Current will flow through the Motor's windings and through the power supply at the same time, in a circular fashion.
For an example frequency of 1Hz, connect the leads so X1 = "+" and X2 = "-".
Let this run for 0.5 seconds.
At 0.5 seconds, remove the leads, then reconnect in opposite fashion (X1 = "-", X2 = "+"). Continue doing this over and over and over.....
What has been described here is the way your 1? Induction Motor will see currents from either a 1? or 3? Transformer.
Scott35
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: gingle phase from three phase
Frank a single phase load conected to a three-phase panel will only see the power produced by one set of windings in the generator. in this way it will see the 180 deg. as it will not care about the phase that it is not connected to. Ed could draw a diagram of a three-phase generator and a single phase load it would be clearer. but if a load only see's one winding of the generator it see's just a single phase generator and since the generator is nothing but three single phase generators then when you connect to just one set of windings it will act just like a single phase generator. as Scott has said it is when you place a load across all three legs is when the timing of the 120 deg. comes into play.
Just a thought even though we have single phase transformers and single phase panel's they all are still getting there power from one/two legs of a three-phase supply on the primary side of the transformer. this is why we see three hot wires going down the poles or if there is only one wire if you follow it you will find that it comes from a three-phase line down the road.
Frank a single phase load conected to a three-phase panel will only see the power produced by one set of windings in the generator. in this way it will see the 180 deg. as it will not care about the phase that it is not connected to. Ed could draw a diagram of a three-phase generator and a single phase load it would be clearer. but if a load only see's one winding of the generator it see's just a single phase generator and since the generator is nothing but three single phase generators then when you connect to just one set of windings it will act just like a single phase generator. as Scott has said it is when you place a load across all three legs is when the timing of the 120 deg. comes into play.
Just a thought even though we have single phase transformers and single phase panel's they all are still getting there power from one/two legs of a three-phase supply on the primary side of the transformer. this is why we see three hot wires going down the poles or if there is only one wire if you follow it you will find that it comes from a three-phase line down the road.
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