Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [neutral]

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

92 questions
38
votes
5 answers

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 devices by connecting it to the case (cover)? Can…
Michael George
  • 3,742
  • 13
  • 53
  • 84
16
votes
4 answers

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 very hot) compared to the live pin. How is this…
ilyas
  • 339
  • 3
  • 7
10
votes
4 answers

Can I drive a 3-wire-delta-input appliance with a wye-output transformer?

We have a high-current industrial machine rated for 3-phase at 230 V; the nameplate literally says "PHASES: 3Ph + PE", "VOLTAGE: 3X230VAC", and "FULL LOAD: 92A". There are only three input terminals (neglecting the PE, which is attached to the…
bernz
  • 203
  • 6
10
votes
10 answers

Why is the fuse connected to the live wire?

As far as I can understand the concept of AC, it does not matter which wire is live or neutral as this changes like 100 times per second (implying 50Hz) I believe. I read the fuse must be connected to the live wire, as close as possible to the AC…
Musa
  • 296
  • 2
  • 11
10
votes
6 answers

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

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 coming into my home and most of it exits my home on…
UA412
  • 173
  • 1
  • 4
9
votes
2 answers

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 found this image online.
rustyelectron
  • 97
  • 1
  • 1
  • 6
8
votes
4 answers

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 the following figure, in which AC and DC circuit…
thece
  • 679
  • 2
  • 5
  • 14
7
votes
5 answers

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 circuit? My understanding is that hot provides charged…
Cowthulhu
  • 181
  • 1
  • 2
  • 6
5
votes
4 answers

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 higher than the voltage of an individual phase by a…
penguin99
  • 829
  • 1
  • 8
  • 22
3
votes
2 answers

What is the purpose of the 1 Mega-ohm 1/2 watt resistor between neutral and ground, in a vintage audio amplifier (SONY model STR-7800SD)

I own an old SONY radio / amplifier, model STR-7800SD. I opened it and I saw a resistor between one of the AC lines and the chassis. The funny thing is that it has a REVERSIBLE 2-prong plug! So, I found its service manual on hifiengine.com and…
SimplyTech
  • 31
  • 2
3
votes
2 answers

Why do we connect neutral and ground at the transformer?

Why do we connect neutral to ground at the transformer, why can't we just connect that neutral to the ground at our house?
Shashank
  • 51
  • 1
  • 5
3
votes
3 answers

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 seems questionable) and is rated for 100W continuous…
john01dav
  • 170
  • 8
3
votes
2 answers

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 the incoming power. The incoming single-phase…
Ryan Griggs
  • 2,596
  • 2
  • 30
  • 53
3
votes
2 answers

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 line tension in respect with the PE reference, but…
Arthur
  • 31
  • 2
3
votes
3 answers

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

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 damaged? If I'm correct, AC doesn't have polarity…
enoob
  • 71
  • 2
  • 6
1
2 3 4 5 6 7