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On a typical house plug, there are three wires - the positive, neutral, and ground. Ideally, the positive and neutral wires carry the current (the neutral wire provides the return path for the current from the positive wire), and the ground wire carries no current.
In a three phase system, you have three phase voltages of the same magnitude (ideally), but the three phase voltages are out of phase with each other by 120 degrees - meaning one is at 0 degrees, one is at 120 degrees, and one is at -120 degrees if you looked at them on an oscilloscope, and referenced to one phase.
If you take (1 at an angle of 0 degrees) + (1 at an angle of 120 degrees) + (1 at an angle of -120 degrees), you will get zero. Thus the return path in three phase power is shared between the three phases, and the neutral wire in a 4 wire, three phase system is equivalent to the ground wire connected to your wall plug. The ground wire will only carry current when the "vector sum of the phase voltages does not equal zero" (meaning the simple equation at the beginning of this paragraph does not sum to zero - whatever it sums to is what is flowing in the neutral).
What else can I help you with?
Which starter is best for 7.5 hp 3phase motor?
Which starter is best for 7.5 hp 3phase motor?Read more: Which_starter_is_best_for_7.5_hp_3phase_motor
When phase and neutral are glowing what is the problem in circuit?
There is more current flowing and the wire can not flow that much current.
GFCI circuitry often checks for a difference in current between the ground and neutral?
A GFCI monitors the current in the ungrounded (hot) conductor and the grounded (neutral) conductor. If there is more than 6mA of current difference between the two the GFCI will open the circuit.
Why does the grounded wire not measure current when tested even though it is returning the same amount delivered?
By grounded wire, I assume you mean the neutral, which does normally carry current, as opposed to the ground or earth wire, which never carries current except during a fault condition. It does, actually. Current flowing through a wire doesn't know or care whether the wire is grounded. Current is current, and an amprobe or other instrument will measure it. If the neutral is mart of a multiwire circuit, where it serves more than one hot wire, you can run into a 'balanced load' condition. This is where current flowing in one hot wire flows out the other, and not the neutral. For example, take a typical US 120/240 volt utility service, with two hot wires and a neutral. Connect a 1200 watt heater to phase A. You would measure 10A on phase A, 10A on the neutral, and zero current on phase B. Now add a 600 watt heater on phase B. You would measure 10A on phase A, 5A on phase B, and only 5A, on the neutral. The 5A flowing in phase B also flows in phase A, 'stealing' current from the neutral. Now, remove the 600 watt heater from phase B and replace it with a 1200 watt heater. Now you would measure 10A on phase A, 10A on phase B, and zero current on the neutral. The two 10A currents on the two hot wires balance each other out, leaving no current left to flow in the neutral. This is why the NEC allows hot conductors from different phases to share a neutral, because the current can never exceed one circuit's current. As you load up both hots equally, the neutral current reduces. This is a common reason why you would see zero amps on a neutral. But if the current flows, you can and will measure it, even on a neutral. Oh, also be sure you don't have an alternate path to ground! If there is a ground fault or miswired connection, maybe there is ground current flowing, just not in the wire you think!
Does neutral wire carry voltage in a closed circuit?
The ground wire should carry no current at all, it is there in case of a short circuit to carry the (short circuit) current back to the breaker panel to trip the breaker. The neutral will carry the unbalanced load current between the 240 volt legs. e.g. L1 and N (neutral) 120 volts the load draws 8 amps. L2 and N (same neutral) 120 volts the load draws 12 amps. The difference between the two amperages is what the neutral will carry 12 - 8 = 4 amps.
How much current carrying in neutral?
In the US , for example, the live wire changes from zero to +120 volts rms, then back to zero, then to -120 volts rms, then back to zero. It goes through that cycle 60 times every second. At all times throughout each cycle, the live wire "feeds" the current at the varying voltage and the neutral wire "returns" it to the power source.A neutral wire is always needed as the return path back to the power station for any single-phase circuit in which a single live wire feeds alternating current into the connected load.As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.Before you do any work yourself,on electrical circuits, equipment or appliances,always use a test meter to ensure the circuit is, in fact, de-energized.IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.
How 3 phase unbalanced current flow through neutral?
Kirchoff's Current Law states that the signed sum of the currents entering a node is zero. If the neutral point is the node, then, in a balanced system, hot matches the other two hots, resulting in no current through neutral. Any imbalance, either due to neutral to hot current flow that is not balanced by the other two neutral to hot current flows, or due to ground fault, will result in a current flow on neutral, so that the sum of zero is maintained.When you think about this, remember that the law said "signed" and "entering". When you analyze a circuit, simply be consistent in your usage. For instance, in a balanced system, current entering the neutral node from one hot side is considered positive, and the current entering the neutral node from the other hot side is considered negative, i.e. it is leaving, not entering.This gets more complicated in three phase power, because now you have to consider phase angle, but the concept is exactly the same...If you are connected in wye, with a neutral, then the neutral conductor will have zero current on it only if the three phase hots have the same current on each. If you do vector analysis on this, adding up sin(x), sin(x+120), and sin(x+240), you get zero.The same thing happens when you are delta connected, without a neutral, but then the imbalance occurs out in the distribution system, beyond the service transformers, because the distribution system is generally a wye system.Ground fault will, of course, "change the rules", because you no longer have only four paths to that neutral point node. In fact, that is how ground fault current interrupters (GFCI's) work - they measure outbound current and compare it to inbound current - they must be equal and opposite, i.e. they cancel each other out - otherwise there is another path - a ground fault - and the device trips.
Is soapy not neutral?
Yes, it is not neutral; more frequently basic.
Is soapy water not neutral?
Yes, it is not neutral; more frequently basic.
What are some current color trends in men's sweaters and vests?
According to Men's Fashion (www.mens-fashion.lovetoknow.com), the current trends in choosing the proper colors and patterns are as follows: argyle or a solid neutral pattern "will say that you like fashion," whereas neutral colors and stripes state that "you appreciate trends and theunexpected a bit more than the next guy might."
Gfci circuitry checks for differences in current between the?
...hot and neutral conductors. (Sounds a lot like a homework question. If so, spend a little more time reading the textbook!)
How 3 phase motors runs without neutral?
how does the current flow in a three phase circuit when neutral is not connected? A balanced three-phase 4-wire circuit - one with equal currents in all three live wires - has zero current flowing in the 4th wire, the neutral. Therefore the neutral wire can be removed, leaving just the three live wires. Instantaneously, the sum of the three currents is always zero in a balanced three-phase circuit. As an example, when the current reaches its peak in one wire, say 10 amps, the current in the other two wires is one half, 5 amps, in the opposite direction. Therefore the two wires take the return current for the first wire. This state of affairs happens continuously at every instant in the AC cycle, so three lives wires are all that is needed.
