Quote:
Originally Posted by Terry D View Post
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No one meant sharing a neutral with two hots on the same leg. You definatly cant do that.
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That seems to be what the posted I responded to did say. Maybe the terminology is unclear. Most understood it as MWBC.
Quote:
It wouldn't even be called a neutral, it would be the grounded conductor.
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NO, the EGC is a completely different thing. The neutral is typically connected to ground at the panel but is NOT a "grounded conductor". We have to make certain no current flows in the EGC or it may not protect life in the event of a fault.
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A grounded conductor is not the same as an equipment grounding conductor.
A neutral is the intentionally grounded circuit conductor intended to carry current of the circuit.
neutral = grounded conductor
An EGC is also an intentionally grounded conductor. It however, does not carry circuit current and is present only to provide a low impedance fault path to ensure rapid fault clearing time.
Look up both definitions in NEC. read article 200 and 250 for contrast.
Quote:
A neutral carries the unbalanced load of a multiwire circuit.
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Which by definition is a neutral shared between two hot wires and is not permitted, in general, by NEC.
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Article 210.4 seems to read otherwise. They are permitted.
Quote:
Residential power is not 2 phase, it is single phase.
Engineers typically refer to it as two phase, which it technically is, but some electricians prefer the term split phase. The 240 VAC (or 208 VAC) voltage provided to the residence has a reference neutral and each leg of the 240 VAC is 180 degrees out of phase. Typically it is generated from one pair of a three phase supply, and whether it is 240 VAC or 208 VAC depends on whether the 3 phase is wye or delta.
Hayt and Kemmerly is the classic text and treats the subject well if you want to learn more about this.
Last edited by Dh3256; Today at 05:16 PM.
Sure, any sinusoidal wave forms that have the same frequency and maintain a phase shift are different phases.
The original 2 phase systems had a 90 phase shift. It is still recent enough that confusion results based upon its prior configuration. Using the term split phase easily conveys the 180 phase shift obtained from one center tapped winding.
Generally, today when reference is made to 2 phases, it is used in the context of 2 out 3 the phase conductors found in a 3 phase system. A split phase secondary transformer is referred to as single phase xformer. You won't find a 2 phase xformer today.
Originally Posted by Terry D View Post
*************
No one meant sharing a neutral with two hots on the same leg. You definatly cant do that.
*********
That seems to be what the posted I responded to did say. Maybe the terminology is unclear. Most understood it as MWBC.
Quote:
It wouldn't even be called a neutral, it would be the grounded conductor.
********
NO, the EGC is a completely different thing. The neutral is typically connected to ground at the panel but is NOT a "grounded conductor". We have to make certain no current flows in the EGC or it may not protect life in the event of a fault.
***********
A grounded conductor is not the same as an equipment grounding conductor.
A neutral is the intentionally grounded circuit conductor intended to carry current of the circuit.
neutral = grounded conductor
An EGC is also an intentionally grounded conductor. It however, does not carry circuit current and is present only to provide a low impedance fault path to ensure rapid fault clearing time.
Look up both definitions in NEC. read article 200 and 250 for contrast.
Quote:
A neutral carries the unbalanced load of a multiwire circuit.
***************
Which by definition is a neutral shared between two hot wires and is not permitted, in general, by NEC.
************
Article 210.4 seems to read otherwise. They are permitted.
Quote:
Residential power is not 2 phase, it is single phase.
Engineers typically refer to it as two phase, which it technically is, but some electricians prefer the term split phase. The 240 VAC (or 208 VAC) voltage provided to the residence has a reference neutral and each leg of the 240 VAC is 180 degrees out of phase. Typically it is generated from one pair of a three phase supply, and whether it is 240 VAC or 208 VAC depends on whether the 3 phase is wye or delta.
Hayt and Kemmerly is the classic text and treats the subject well if you want to learn more about this.
Last edited by Dh3256; Today at 05:16 PM.
Sure, any sinusoidal wave forms that have the same frequency and maintain a phase shift are different phases.
The original 2 phase systems had a 90 phase shift. It is still recent enough that confusion results based upon its prior configuration. Using the term split phase easily conveys the 180 phase shift obtained from one center tapped winding.
Generally, today when reference is made to 2 phases, it is used in the context of 2 out 3 the phase conductors found in a 3 phase system. A split phase secondary transformer is referred to as single phase xformer. You won't find a 2 phase xformer today.
...not in post38