Table of Contents
- 1 Where is the neutral on power lines?
- 2 Do power lines have a neutral?
- 3 Where does the neutral wire come from?
- 4 Can ground and neutral be connected together?
- 5 How do you find the neutral current in a three-phase system?
- 6 What happens if neutral wire is not connected?
- 7 What happens when a neutral wire is disconnected in a 3 phase system?
- 8 How does a 3 phase AC transformer work?
Where is the neutral on power lines?
Consider what would happen if you economised and only used one conductor for both neutral current, and safety earth. Now imagine excessive current flows because you overload the circuit, or a bad connection develops high resistance and overheats, and the neutral/earth conductor melts before the live…
Do power lines have a neutral?
The transmission lines connect to a grounded neutral conductor that gives a return path for electricity. The ground wire or grounding conductor is also called the multi-grounded neutral line.
Why is there no neutral wire in 3 phase?
A neutral wire allows the three phase system to use a higher voltage while still supporting lower voltage single phase appliances. In high voltage distribution situations it is common not to have a neutral wire as the loads can simply be connected between phases (phase-phase connection).
Do high voltage lines have a neutral?
High voltage power lines (the ones on huge towers with long insulators) are almost without exception 3-phase Delta alternating current, two independent groups if the tower has 6 wires. No neutral or ground needed.
Where does the neutral wire come from?
The neutral point of the system is at the center-tap on the secondary side of the service transformer. That’s where your neutral wire comes from.
Can ground and neutral be connected together?
No, the neutral and ground should never be wired together. This is wrong, and potentially dangerous. When you plug in something in the outlet, the neutral will be live, as it closes the circuit. If the ground is wired to the neutral, the ground of the applicance will also be live.
What are the cables on power lines?
The most common conductor in use for transmission today is aluminum conductor steel reinforced (ACSR). Also seeing much use is all-aluminum-alloy conductor (AAAC). Aluminum is used because it has about half the weight and lower cost of a comparable resistance copper cable.
How can you tell a cable line from a power line?
It is easy to tell power lines apart from these types of lines – power lines are always higher up on the pole, they always have insulators, and they do not touch other lines. Cable and telephone lines are located further down the pole and are directly attached to power poles without insulators.
How do you find the neutral current in a three-phase system?
Note the neutral formula. If A, B and C are the three phase currents, the formula to find the neutral current is the square root of the following: (A^2 + B^2 + C^2 – AB – AC – BC).
What happens if neutral wire is not connected?
With a regular 120-volt AC circuit, the neutral wire provides a return path to earth ground. If the neutral wire disconnects, it would stop the flow of the electricity and break the circuit. The role of the neutral wire is to provide this path to the electrical panel to complete the circuit.
What happens if neutral touches ground?
The neutral is always referenced to ground at one, and ONLY one, point. If you touch the neutral to ground anywhere else, you will create the aforementioned ground loop because the grounding system and the nuetral conductor are now wired in parallel, so they now carry equal magnitudes of current.
What is the voltage between two phase wire?
The distribution is generally single phase two wire and three phase four wire. The voltage between any phase wire and neutral is 230 volts and between any two phase wire is 400 volts.
What happens when a neutral wire is disconnected in a 3 phase system?
It is clear from the above illustration that if the neutral wire is disconnected in a 3 – phase, 4 – wire system the potential difference across the high resistive load is increased and the potential difference across the low resistive load is decreased.
How does a 3 phase AC transformer work?
Long distance AC transmission is normally 3-phase without neutral. At the receiving end, a 3-phase transformer lowers the voltage from the “several kV range” to normal household levels (maybe a bit higher if it feeds an intermediate system).
What are the voltages of the Transformers in a sub-station?
The voltage is ultimately stepped down to 400/230 volts i.e. 400 volts for bulk consumers and 230 volts for general domestic consumers. The connections of the windings of the transformers installed in the sub-station are in delta on the primary side and in star on the secondary side.