Questions tagged [neutral]

a circuit conductor that normally carries current, and is connected to ground (earth) at the main electrical panel.

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34
votes
5answers
23k views

Why don't we use neutral wire for to ground devices and earth wire for closing the circuit?

I know that the neutral point of a distribution transformer is connected to the grounding (earthing) wire, so I think they are the same. Can I use the neutral wire for protecting metal-cased electric ...
16
votes
4answers
6k views

Why is the neutral pin hotter than the live pin?

I frequently use an Immersion Rod Water Heater (shown below) and I have noticed that the after unplugging the heater, the neutral pin of the 3 pin plug is quite hot (about 5 degrees more - but not ...
10
votes
6answers
8k views

Am I compensated by the electricity company for electricity that exits my home on the neutral wire? [closed]

DISCLAIMER: I am not an electrician or electrical engineer. Let's say that all I have running in my home is a 10 watt LED light bulb (nothing else). This bulb uses very little of the electricity ...
7
votes
1answer
13k views

Why is neutral wire connected to ground at the transformer?

I understand the use of ground wire at the home appliances but why is the neutral wire connected to ground at the transformer? Why doesn't the neutral wire go back to the power generation plants. I ...
6
votes
4answers
7k views

Why cut both live and neutral wires?

It is a common practice, for high power loads such as boilers, furnaces, etc., to install a circuit breaker that "cuts" both live and neutral wires - at least in Europe. In my search for EVSE, I saw ...
5
votes
5answers
2k views

How can a circuit not have a neutral?

I've been making plans to install a NEMA 6-50 outlet in my garage, but I don't understand how it can not have a neutral, and instead have two hots (at 120v each) and a ground. What completes the ...
5
votes
4answers
2k views

Does the neutral wire have any voltage?

In this article, the author talks about 3 phase and the magic of a missing neutral wire. And there's the following paragraph: In a 3-phase system the voltage between any two phases is 3 times ...
3
votes
3answers
1k views

What does it mean when my car inverter's labeling says “Neutral Floating”? Is it safe to use?

I recently came across a fairly old car inverter. It plugs into a 12v DC lighter socket, and outputs 115 Vac at 60 Hz, and has a normal American outlet on the side of it (with a ground pin, which ...
3
votes
2answers
189 views

Why do we connect neutral and ground at the transformer? [closed]

Why do we connect neutral to ground at the transformer, why can't we just connect that neutral to the ground at our house?
3
votes
4answers
968 views

Hot and neutral have similar voltage to ground - finding the problem

I have an APC battery backup and surge protector for my computer. It has a light, labeled "Building wiring fault." This light is on, and my computer will not start. I am unemployed and my landlord is ...
2
votes
5answers
262 views

What are the reasons behind marking neutral and line terminals on a power supply AC input?

Even though AC has no polarity, almost all the power supply AC inputs or most AC powered device input terminals indicate line and neutral terminals as L and N just like in the following example: Is ...
2
votes
2answers
1k views

Should neutrals be tied together or left separate?

I'm working on a control panel. The panel is powered by 120VAC single phase (USA). The panel has a battery backup unit (UPS) which powers the panel if the incoming power goes out, and which filters ...
2
votes
1answer
572 views

Grounding conductor has a non-zero voltage (i.e. with respect to “true” ground). Why?

We're building a new house and I'm not confident with the skills of the electrician who installed the receptacles. In our country, residential structures are supplied with 240 V, 60 Hz (single phase). ...
2
votes
2answers
3k views

Where does branch circuit neutral current go in a single phase or three phase electrical panel?

Specifically, I would like to know the exact path of travel for the neutral current when it comes back from a load to the electrical panel. I am an electrician of 20 years and have recently acquired ...
2
votes
3answers
5k views

Does reversing polarity in AC damage the equipment? (Sonoff Wifi Switch) [closed]

Firstly, I am a beginner. Excuse me if this is a dumb question. I have ordered a Wi-Fi switch named Sonoff. I have a doubt whether the device will work if the polarity is reversed or will it get ...
2
votes
1answer
308 views

Why short circuit occur when the hot line touches the neutral wire (aka ground)?

The charges move from negative (hot wire) to positive/negative (neutral) to make the device work right? So why would the Short occur only when they are directly connected? Wouldn't they just flow ...
2
votes
1answer
203 views

Odd voltage readings between phase-ground, phase-neutral, neutral-ground

Recently i tried gathering voltages from few AC outlets in my house. I got following readings using a dmm Phase-Ground = 398V-400V (should be around 240V) Phase-Neutral = 230 V Neutral-Ground= 210 V ...
2
votes
1answer
1k views

Connecting a surge protection device

I've just learned about the surge protection device (SPD). As I was reading about its connection in a three phase line, I came across this scheme: I understand that the SPD's are there to limit the ...
1
vote
2answers
250 views

Meggering Three Phase Motor (Phase-GND, Phase-Neutral, GND-Neutral)

When meggering a three phase motor, could someone please help me understand the values we would expect to see for a motor with no insulation or ground faults. From my understanding: Phase-GND: ...
1
vote
2answers
2k views

What is the difference between neutral and ground?

What is the difference between neutral and ground? I do not understand the difference.
1
vote
2answers
191 views

Can I put a low current relay between line (or neutral) and the ground wires to detect polarity?

Can I put a low current (<5 mA) 230V coil, NC (normal close contact) relay between one wire of mains and the ground (earth) wire in order to check mains polarity? In theory if the wire is line (...
1
vote
7answers
3k views

Neutral and live holes/wires

Is the neutral hole socket on the left or the right side? Is this universal to all countries and most houses? The neutral wire is usually at 0V relative to earth right? Or 0V RMS? HYPOTHETICALLY, if ...
1
vote
1answer
85 views

Running long underground line without neutral or safety ground using transformer, is it to code?

My prior question asked about a single wire earth return [SWER] system. Both questions are aimed at meeting the same end requirement but this is a sufficiently different method that many of the issues ...
1
vote
1answer
86 views

Question on Ground/Neutral connection for a 220V equipment

I sketched the following schematic from a motor controller board that has to be operated at 220V from L1 to L2. The earth wire is connected to the chassis of the machine. Where I live, it's common to ...
1
vote
1answer
105 views

Why is earth at 0 V with respect to phase?

In 3 phase transmission lines we have different voltages depending on how we measure it. Phase to phase voltage is going to be 1.73 times more than phase to neutral. So far I understand everything ...
1
vote
0answers
197 views

Effect of the neutral current to a system when a 3-phase facility is used as unbalanced

Normally 3 phase-systems are used for balanced loads like in 3-phase AC induction motors. I know that in a balanced star configuration the total current across the neutral is zero. But what if each ...
1
vote
3answers
122 views

Using the neutral instead of the earth to supply electrons

I'm working on a VAN DE GRAAFF generator and I need to connect the bottom comb to the earth ground. But in my country we do not have a ground line . Can i use the neutral line instead and connect the ...
0
votes
4answers
446 views

In any electrical equipment having single ph 230 v ac supply ,if neutral and earth wire exchanged then what will be the consequence

I am handling the supply in a locomotive coach and have noticed that the neutral and earth wires have been accidentally flipped,inside the appliance(hot case) is there a problem from the safety point ...
0
votes
5answers
1k views

Why is the Earth a useful reference of electric potential?

I may be a little confusing, but I honestly need a good help to make me understand certain things. I like very much to learn theory, but I feel that if I learn it without associating to the real life, ...
0
votes
3answers
492 views

Why do electrical systems have neutral, live and ground when electronic systems have only VCC and ground?

Wouldn't it be simpler if electrical systems take away the neutral and just have live and ground similar to electronic systems?
0
votes
1answer
127 views

Why no current in neutral wire_kids question

One school child asked me - If current means flow of electrons, or entering to a bulb from one wire (Live) then going back through another wire, then why there is no current in the neutral wire, ...
0
votes
2answers
4k views

How to calculate the neutral wire size of a home (department)?

I know that in electrical grid, Neutral wire is a non current carrying conductors so its cross section area is smaller than the cross section area of the live conductors. I think it has half of size ...
0
votes
1answer
50 views

Home electrical transmission question [closed]

AC current is sine wave with 60 hz frequency - how is this helpful in understanding electricity and transmission? Does the sine wave progress through electric wire or stands static and oscillates? ...
0
votes
2answers
239 views

480v delta/400v wye with Neutral ungrounded

I have a European machine using a 480/400 volt three phase transformer. The neutral conductor is used to power some devices at 230 volt. The manuf. insists that the neutral must not be solidly ...
0
votes
1answer
9k views

when does the neutral wire in a 3 phase system carry voltage?

I am curious, and I've found a bit of information online, but maybe its not clicking in my head... when does the neutral line in a 3 phase system carry voltage. i do understand the answer is quite ...
0
votes
1answer
28 views

Wiring 3P+N Device to 3P+N+E Connection

I have a 415V compressor with a 3-phase Commando plug in the configuration 3P+E, however my wall socket is 3P+N+E. Is it possible to change the plug on the compressor to a 3P+N+E without connecting ...
0
votes
3answers
1k views

50 Volts on the Neutral (180 Volts on the Live) bad or safe?

We have an off-grid UK home on occasion powered by a generator (MOSA GE 6000 SX/GS). Due to the design of the generator, it has two modes: centre-tapped-earth 110 V, and 230 V. When running in 230 V ...
0
votes
1answer
123 views

Running a long 120VAC line without a neutral

Source is a home 120/240VAC with pole transformer. I want to direct bury a 500 foot 120V line to run some battery chargers and dont need more than 10 amps. Why cant I only run a single large ...
0
votes
2answers
1k views

Why is neutral required in three phase charging of Electric vehicles?

Talking about both three-phase AC as well as DC fast charging (wherein 3 phase AC is converted to DC) in EVs, I think that the 3-phase rectifier represents a balanced 'load'. Therefore I want to know ...
0
votes
2answers
136 views

How does having neutral make electrical systems safer than electronic systems which do not have neutral? [duplicate]

Electrical systems have neutral besides live and ground. Electronic systems have only VCC and gnd. I read that having neutral is necessary for safety in electrical systems because of the higher ...
0
votes
2answers
45 views

L and N switched, from a functional point of view, what difference does it make for the device being powered?

Consider a generic single phase AC 240 V (or 125V) device for home use such as a hair dryer. From a purely functional point of view, what difference does it make if a phase is switched with the ...
0
votes
3answers
109 views

Neutral wiring in residential homes

I understand from the diagram below that the neutral wire provides a return path to complete the circuit so that the current can flow. But once the current goes back to the distribution transformer, ...
0
votes
1answer
186 views

Can connecting just neutral wire of power supply to a PCB (VDD not connected) cause sparks and burn out decoupling capacitor?

I have an embedded system and one of the PCBs in the module should be connected to a 5V power supply -> positive(+) and neutral(-). The NEUTRAL knob is directly tied to the GROUND knob in the power ...
0
votes
4answers
3k views

Neutral and the earth are bonded at the main panel or the substation but why is only earth wire used for safety?

Typical distribution system can be illustrated as: Here are my premises (and assumptions): 1-) Chassis in a house must be connected to the earth, not to the neutral. 2-) The earth and the neutral ...
0
votes
1answer
840 views

What would happen if a neutral wire and a hot wire were vastly different lengths?

Pretend you had a 120v load, where the hot (ungrounded conductor) was say only 5 feet in length from the source to the load, but the neutral was say, 1000 feet. Excluding things such as voltage drop (...
0
votes
1answer
484 views

High neutral-to-ground voltage of switching mode power supplies

I am attempting to create a sine wave signal from 0V to 12V at 40 Hz and up to 1.4A, with original power input 120VAC 60 Hz wall power. I've come up with the circuit below, which I'm pretty sure ...
0
votes
1answer
110 views

Twin wire neutral

I work in the power distribution industry and recently came across a 3-phase LV circuit with "twin-wired neutral" (i.e. two neutral cables inter-winded, therefore five cables total). What would be the ...
0
votes
3answers
120 views

What's the use of neutral wire in single phase home supply? [duplicate]

I am aware that the neurtal wire provides a return path for the current to the power source. But that neutral wire too, is connected to the ground at somewhere between the load and the source. My ...
0
votes
0answers
50 views

Switch type for electrical generator bonded to floating neutral

I have an electrical power generator and for it to properly work with it connected to the house it must be converted from bonded neutral to floating neutral according to these instructions. I was ...
0
votes
1answer
48 views

Connect the oscilloscope to equipment with a common neutral and ground

I watched a video. At 3 minutes, the situation is shown when neutral and ground are joining. Why can this be dangerous? If we are talking about an oscilloscope, the crocodile must already be connected ...