Neutral to minimize voltage imbalance
Neutral to minimize voltage imbalance
(OP)
If a Feeder ckt supplies only 3-ph and 208 1-ph loads, will adding the neutral conductor minimize voltage imbalance ? Or does neutral accomplish nothing ?
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Neutral to minimize voltage imbalance
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Neutral to minimize voltage imbalanceNeutral to minimize voltage imbalance(OP)
If a Feeder ckt supplies only 3-ph and 208 1-ph loads, will adding the neutral conductor minimize voltage imbalance ? Or does neutral accomplish nothing ?
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RE: Neutral to minimize voltage imbalance
RE: Neutral to minimize voltage imbalance
RE: Neutral to minimize voltage imbalance
There are cases where connecting the neutral will solve voltage inbalance, but this is because a ground fault exists that will be revealed (in a bad way) when you connect the neutral to ground.
RE: Neutral to minimize voltage imbalance
For instance let's take a building of 3 dwelling units. Let's say apartment A load is 1000 w at 208 V. Phase A to neutral resistance is then ResA=208^2/1000=43.26 ohm.
Let's say apartment B load is 100 w and Phase B to neutral resistance will be ResB=208^2/100=432.64 ohm.
Now, let's say no load for apartment C. If no neutral is provided-that means the neutral is disconnected at the common building supply cable- then from live A to live B will be 208*sqrt(3)=360 V.[See the sketch]
The common current flowing from A to B=360/ (432.64+43.264) =0.75646 A.
Then the A load will get 0.75646*43.26=32.72 V and the load B 0.75646*432.64=327.27 V.
If a neutral continuous conductor is provided the voltage will be equilibrated and the each individual current will flow back to the source [transformer].
RE: Neutral to minimize voltage imbalance
I believe that you misunderstood the OP. The system is 208V Ø-Ø (208/120Y - common in USA) and there are no loads connected Ø-N.
I agree with others that there is no need for a neutral conductor. There is a need for an equipment grounding conductor to ensure tripping for ground faults.
RE: Neutral to minimize voltage imbalance