"unbalanced currents"
- Thread starter molsen
- Start date
- Status
Ed MacLaren
Senior Member
Re: "unbalanced currents"
I'm not familiar with that rule, but if you are referring to unbalanced load current in a multi-wire circuit, it is the current in the neutral wire, and is calculated as the difference between the currents in the ungrounded conductors.
In the example below, the unbalanced load current is 10 amps.
Ed
[ September 08, 2004, 05:55 PM: Message edited by: Ed MacLaren ]
I'm not familiar with that rule, but if you are referring to unbalanced load current in a multi-wire circuit, it is the current in the neutral wire, and is calculated as the difference between the currents in the ungrounded conductors.
In the example below, the unbalanced load current is 10 amps.
Ed
[ September 08, 2004, 05:55 PM: Message edited by: Ed MacLaren ]
electricman2
Senior Member
- Location
- North Carolina
- Occupation
- Retired Electrical Contractor
Re: "unbalanced currents"
Ed,he is referring to the derating rule for more than 3 current carrying conductors. The neutral in the diagram you show would not be counted for derating purposes.
Ed,he is referring to the derating rule for more than 3 current carrying conductors. The neutral in the diagram you show would not be counted for derating purposes.
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Re: "unbalanced currents"
The good part is that you don?t have to worry about how imbalanced the current is. If all of the load was on Phase A, and none on Phase B, then the neutral current would equal the Phase A current. In this case, the total heating value of all current in all wires would be no higher than it would have been, if the currents were perfectly balanced. That is true for 3-phase systems as well.
Now, harmonics are a different issue, but that was not part of the question.
The good part is that you don?t have to worry about how imbalanced the current is. If all of the load was on Phase A, and none on Phase B, then the neutral current would equal the Phase A current. In this case, the total heating value of all current in all wires would be no higher than it would have been, if the currents were perfectly balanced. That is true for 3-phase systems as well.
Now, harmonics are a different issue, but that was not part of the question.
lady sparks lover
Senior Member
Re: "unbalanced currents"
We had this question before....
Does anyone find a lot of unbalanced service loads, and therefore have high neutral current??
I've seen it a few times, but mainly on panels with the harmonic problems. Other than that fine here.
We had this question before....
Does anyone find a lot of unbalanced service loads, and therefore have high neutral current??
I've seen it a few times, but mainly on panels with the harmonic problems. Other than that fine here.
- Status