Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [earth]

The tag has no usage guidance.

0
votes
0answers
19 views

Chassis ground with multiple isolated power domains

Referencing this excellent question & answer Chassis ground question, how does one handle multiple isolated power domains? Eg. 3.3v for digital circuits 24v for serial connections 24v for ...
0
votes
0answers
17 views

Not properly grounded/earthed [migrated]

I know next to nothing about electricity and wanted to ask for some advice. Apologies for any cross-posting. I moved into a rented house in Spain a few months ago. Turned out it wasn't grounded. ...
1
vote
1answer
59 views

How to convert high voltage DC at low amps to low voltage DC or AC at high amps?

How to convert high voltage 500 volts DC at very low amps to lower voltage 12 volt DC or AC at high amps? Must I use an electrostatic motor or can I use an op amp? The reason I am posing this is a ...
1
vote
1answer
83 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 ...
0
votes
0answers
42 views

LED lamp lighting with only 1 pin connected to earth which isn't connected to anything

Anyone can help figure this out? Yesterday, while connecting my LED lamp projector with an AC plug, I noticed when one of the 2 pins was connected to the earth pin of my AC extension cord, it would ...
0
votes
1answer
67 views

“Creating” a ground pin for my laptop

I am building a sensor using an Arduino connected to a laptop; I noticed that the readout is much more noisy when I use a non-grounded laptop (either running on battery or connected to a power socket ...
0
votes
0answers
74 views

Out of limit Touch Up current - Servicing PE

My device may not be connected to PE during normal operation, but does require 230VAC mains input. I know I have to take the touch up current of any Y-caps into consideration when developing my ...
1
vote
1answer
26 views

x2y caps and common mode chokes (using both)

I am designing a ultralow noise PCB board. Common mode noise has to be minimized, so I have a question I am planning to use a CMC on power input and to further decrease the common mode noise I also ...
1
vote
1answer
128 views

Ground and earth layers on PCB

I am designing a digital board with USB input and output. Shield of USB is connected to a chassis ground as per USB specs and connected to GND through a R and C in parallel USB power has a common ...
0
votes
2answers
50 views

Questions about earth grounding enclosures

A text mentions about the importance of connecting the earth wire to an instrument case/enclosure as follows: Instruments with ungrounded cases can become lethal devices in the event of ...
0
votes
1answer
44 views

Amplifier does not sound right when balance is centered

I have an HK 590i amplifier. When the balance is centered sound is like coming from far away (voices). Sound is good only when balance is full left or right. I researched the site and found this ...
0
votes
0answers
80 views

No grounding system available for oscilloscope, what other options are available?

Many old buildings/houses in Europe are so old that they were not built with a grounding system. I happen to live in one were this is the case. The problem is that if I want to use an oscilloscope, it ...
0
votes
1answer
80 views

Why is it dangerous for human being to touch one of contacts in AC wall outlet? [duplicate]

Let say we have some DC voltage source which produce some voltage which I will label as V. Let also say that we have some real bulb which is supposed to work when voltage V is applied across its ...
42
votes
10answers
10k views

Why is main's neutral tied to earth?

My dad is an Electrician and I myself am an Electronics Design Engineer, and to this day he still hasn't been able to give me a good reason for this. Consider the two following pictures/situations - ...
0
votes
0answers
356 views

Converting an ATX power supply to bench power supply.

I'm planning to convert an ATX power supply to a bench powersupply. It came to my knowledge that the DC ground is actually connected to earth. As I understand, this might become a major issue if I ...
1
vote
0answers
380 views

Potential difference between DC floating power supply and earth ground

I have a question about a simple DC floating power supply: it is as simple as possible, secondary coil -> bridge rectifier -> filter cap, as shown on the figure below. If I connect the input of the ...
1
vote
2answers
151 views

Modding a Class II switch mode power supply to have output dc- shorted to earth

As above, what are the disadvantages, risks and dangers involved in modding a class II switch mode power supply i.e. a double insulated laptop charger that is ungrounded to have the dc- output shorted ...
0
votes
4answers
261 views

Tiny shock from 230V AC?

So first at all this question isn't really about electrical engineering, but about electricity in general. However, I think this is the best place to ask, correct me if I’m wrong. Also I’d like to ...
2
votes
1answer
131 views

Earth ground to dsub9 shell

I have an enclosure containing an earth ground line. It has a brass earth ground bus that is connected to: the input earth pin of a 120V single-phase mains IEC320-C14 connector the output earth pin ...
0
votes
4answers
1k 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 ...
1
vote
1answer
107 views

Op. Amp. read variation when Earth is connected with Signal GND

I've made this simple circuit to read the line voltage (the 1 pin is conected in a uC by a resistor): In the image NEUTRO is Mains Neutral AC, FASE is Mains Line AC and TENSÃO is the signal to the uC ...
2
votes
2answers
286 views

Clamping the output ground very close to earth ground

I've noticed that the output ground of most power supply are not quite the same as earth ground. The DC is nearly negligible, but there is usually an AC component between output ground and earth ...
0
votes
0answers
32 views

Is it possible to detect and filter noise on an earth?

I ask because I have a solar array on my house with micro inverters. The monitor (an Enphase Envoy) no longer detects the the inverters. Troubleshooting suggests noise on the earth, perhaps caused by ...
1
vote
2answers
665 views

Grounding without Ground

My system use only line and neutral connection from mains (no ground.) Inside this system it is converted to 5V using SMPS. My enclosure is metal, I need to ground this enclosure. Since I do not ...
10
votes
2answers
3k views

Are countries that use 2-pin plugs less safe than countries that use 3-pin plugs given that the earth is missing?

Will there be occasions when using 2-pin plugs is safer than 3-pin plugs? Is it accurate to say that 3-pin plugs are always safer given the presence of earth?
3
votes
2answers
1k views

Should I connect a cable's shield to the ground layer of board when it's isolated from earth?

I have a controller board powered by DC that may or may not be isolated from earth ground. The chassis of the device is non-metallic. This board connects through a long (30-40m), shielded cable to a ...
0
votes
6answers
564 views

Is 'grounding a desktop PC via 1MΩ resistor' unsafe when working inside the case?

Activity: maintenance (installing/replacing hardware parts, like motherboard, CPU, DIMMs, graphics cards) inside an ATX case. Goal: ESD protection and user safety. Original question: Is 'grounding a ...
4
votes
4answers
1k views

Resistor or low impedance path between common ground point and mains earth?

A simple EPA (ESD Protected Area) consists of 3 things: wrist strap antistatic mat common point ground Wrist strap and antistatic mat both should grounded to the common point ground. ANSI/ESD S6.1 ...
0
votes
2answers
670 views

Why are laptops grounded to earth via 1E6 ohm resistance and desktops not?

I measured a few laptop AC-to-DC adapters. 1E6 ohm between GND pin (goes into the laptop) and earth prong (into the wall). Desktops are grounded directly to earth: 0 ohm. Why this difference?
0
votes
1answer
121 views

ESD damage due to earth potential drop?

When lightning strikes or the earth wire (from the wall outlet) suddenly gets charged negatively for whatever reason, then, in theory, can it cause ESD-damage to a PC? Because the grounding wire (...
0
votes
4answers
711 views

Antistatic mat instead of antistatic wrist strap?

Just to make sure, before doing something silly: can i place a 2nd antistatic (dissipative) mat on the floor (along the 1st mat on the table) and stand on it with bare feet? Instead of wearing an ...
1
vote
2answers
132 views

Charge after turning off an electronic device

Let's say I've just turned off my Raspberry Pi and put a imaginary boundary around it. Everything not on this picture is outside the boundary. Is the net charge, inside the boundary, neutral?
1
vote
0answers
170 views

MOV failures in DC

We are facing an issue in our protection circuitry. For the below DC design MOV between Earth is getting damaged in the site. MOV 2 & MOV 3 in the circuit is failing in the site. System is ...
0
votes
1answer
407 views

Why am I measuring earth to line voltage as zero? Is that what it supposed to be?

I have a confusion about the topology below: I was wondering the potential difference between the line and earth. So I decided to check this through a 3-prong plug. I thought I would read the same ...
0
votes
3answers
589 views

Does grounding to earth make a circuit (allowing electricity to flow)?

This question is mostly extending on a question that has been asked here: Single terminal of voltage source attached to earth ground I'm learning the basics of electronics and this question has ...
0
votes
3answers
92 views

Earth Grounding an HV Power Supply

I'm using a Matsusada HV Power supply up to 20 kV. The manual mentioned that the ground terminal of the chassis should be connected to earth. And I had a few questions What are the best, or at least ...
0
votes
1answer
49 views

How to decide earth trace width in protection circuit?

I am using the earth trace for protection circuit in telecom system. The protection circuit includes MOV, sidactor & fuse. So please suggest How to calculate the Earth trace width.
-1
votes
1answer
129 views

How to earth connector with plastic case

My board has a power connector from Glenair 171-006. Input is 5V DC. This connector has a plastic case. My question is, can I use one of the connector contacts to connect to EARTH? Will it cause any ...
1
vote
0answers
124 views

DIN Rail with In-Rail Bus - GND/PE design question

We are designing a system that consists of several modules that are mounted on a DIN rail. They are connected to each other using an In-Rail Bus system like this: System design: The 5 bus line ...
13
votes
6answers
2k views

How to stop plastic granules sticking to the iron wall of their silo?

In our factory, we have some large (8 meters tall and 3 meters in diameters) iron silos for storing the plastic compounding material. Every time the silos are getting unloaded from the granules, the ...
1
vote
2answers
468 views

What is the difference between capacitive fault currents and resistive fault currents?

http://uk.megger.com/battery-ground-fault-tracer-bgft\ This website claims that it's product can differentiate between these two fault currents. But I don't know what the difference is.
2
votes
2answers
936 views

Ground Fault Protection in Unearthed HV Systems

I'm working somewhere that uses an unearthed 3.3kV network for safety critical drives. I've been learning about ground fault detection on ungrounded systems, using VT's and measuring voltage across a ...
1
vote
2answers
118 views

Connecting a battery powered circuit to the earh ground [closed]

In the following circuit what would be the effect of tying a circuit to the ground from the -2V rail ? I know that no current would flow to the ground since there is no closed loop formed, but ...
1
vote
2answers
295 views

Permanent magnet DC motor earth wire

I have just inherited a piece of equipment that is powered by a 12V DC permanent magnet motor. My hope is to drive it using an Arduino PWM and a H-Bridge to manage the current requirements (7.3A ...
0
votes
3answers
953 views

Wire the green ac earth wire in wooden chassis?

My own power supply is just about finished. Since i live in Europe the voltage here is 230v, from that it goes into my step down transformer that steps down the voltage to around 20 V AC and then into ...
0
votes
1answer
255 views

Is it possible for lightning strike to travel up ground / earth pin on a mains outlet?

I live in a country that follows the UK mains specification, where there are 3 pins on a wall outlet with the topmost pin being earth/ground. Now, is it possible that during a lightning strike, extra ...
0
votes
4answers
316 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 ...
28
votes
5answers
18k 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 ...
0
votes
3answers
1k views

Can I ground the negative DC bus of a variable frequency drive?

Suppose I have a typical VFD: rectifier, DC bus caps, inverter, feeding a motor. In general it would not be advisable to tie the DC bus to earth ground, because the AC line may also be referenced to ...
1
vote
1answer
998 views

Is power DC power supply ground, connected to the chassis earth on a desktop PC?

When I plug a data-acquisition PCI card to a PC, I'm trying to picture the ground connections. Some following confusion arises: Is the PC motherboard's ground and PCI's ground common? Does a PC have ...