Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [bad-wiring]

A tag for questions about, or involving systems that are not using proper connections, components, or potentially dangerous circuitry.

35 questions
27
votes
6 answers

How do I describe this circuit?

simulate this circuit – Schematic created using CircuitLab Yes, this circuit diagram is correct. No, I did not design it. How do I describe this circuit in words? I thought about "a switch and light bulb in parallel, instead of series" but the…
dpdt
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16
votes
3 answers

How far can mains voltage arc in air?

I wondered this while soldering a mains voltage circuit board and was surprised by how close together the traces were. It has obvious implications in design of electrical plugs, and the proximity of wires when doing anything to do with mains…
M_M
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5
votes
2 answers

Salvage data from a reverse connected thermocouple?

My SAE Baja team had a competition this past weekend, and we were using some thermocouples in order to get some temperature data on the drivetrain and engine. They were hooked up right before the start of the race and I think in the rush were…
SuperNintendoChalmer
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4
votes
2 answers

Is it possible that an outlet can kill AC motors?

I have two recently dead tower fans. The first, I've had for over 6 months, no problems. Recently, I moved it to a new room an plugged it into a different outlet. It died within a day: it seems to be just the main motor, the controls still work as…
Michoel
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3
votes
6 answers

Why is it not advisable to fuse the neutral

I have been doing some research on this question. The answer I get most of the time is that this is for safety reasons. That there can be no current in the neutral that didn't come from the live. If anyone has a clear answer, please tell me.
user104474
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2
votes
3 answers

Does an inexpensive screw terminal "expansion strip" exist?

I've got a messy security panel that needs cleaning up badly, as I need to connect another PCB for remote access and can't get the wires to reliably stay in place: If you look at the black, red, green, and yellow terminals, they already have three…
Dave
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2
votes
0 answers

Is this USB Hub 3.0+2.0 hybrid safe to use?

So I just bought a USB 3.0+2.0 hub hybrid. When I check the PCB, the pin out is new to me (see photo). From host, two of the USB 2.0 data lines (red lines) went straight to the hub IC, then from the IC to the USB 3.0 port (green lines). The USB 3.0…
Milk Boy
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2
votes
2 answers

Led ON on Spike Guard Even When Switch is OFF

I have this spike guard and it's middle led is ON even when the spike guard switch is off. I can see there are various combinations of the led and their meaning. But I see the middle led on when the switch is OFF. Can anyone tell me if anything is…
iwtga
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2
votes
2 answers

Soldering thin leads of a thermocouple

I have a thermocouple with me which is custom made and its leads are very thin. It has a diameter of 0.19 mm and this has to be soldered to a chip (Max6675). This setup will be placed on a harsh environment. I am stumped on how to deal with the…
Vish_evo
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2
votes
1 answer

Un-insulated Ground wire in USB cable

I am attempting to put a switch between the Data + and the ground wires in a USB cable. Now that I have cut open the USB cable, it does not seem to match any of the pinout diagrams I can find online. The next few statements are based on doing…
Tom McElroy
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2
votes
1 answer

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). Here's what I currently know: 1. Hot and neutral…
Darwin Bautista
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1
vote
3 answers

How do I test grounding/lightning protection?

I manage IT for several clients in Central Florida, where we have quite a lot of lightning (the most in the U.S.). I have one client that has trouble keeping electronic devices alive. We have replaced several network devices. I suspect there is a…
Gene McCulley
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1
vote
3 answers

Is it safe for a screw at the terminal block to have multiple wires with fork connector end connected to it?

I have a DC-DC converter (24v to 12v) that has terminal block at its input and output terminal. To understand it better, I've attached the drawing of the converter found in its datasheet. Problem: This converter is used at work. And the existing…
Shuan
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1
vote
1 answer

Ground wire appears live despite not being connected on either end

I have decided to add another plug outlet near an existing blind outlet box. Unfortunately I've found that the existing one doesn't have ground since it's an old building, but that's a problem for another day. After connecting the new outlet, the…
Sašo
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1
vote
1 answer

measuring resistance in a wire with a short

A couple of questions: I have a camper trailer that apparently has a dead short in either the positive or ground wires between the battery and the fuse panel. Someone told me to measure the resistance of the hot wire and ground wire from the fuse…
longtimealaskan
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