A glow stick will tell you if a conductor is hot. My question is why doesn't it glow on the neutral conductor. If you have a 120volt 20 amp circuit that is pulling 5 amps. If it's a single circuit then you will read 5 amps on that neutral. Why doesn't the glow circuit glow in this situation, Its got the same current and voltage.
Current flow
- Thread starter JdoubleU
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frizbeedog
Senior Member
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- Oregon
Jakewhis said:
Just wondering. How do you measure voltage on the grounded conductor?
It's a volt stick. Not a current stick. It detects voltage.
Lift that neutral and then it will work.
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frizbeedog said:
I think that sums it up well.
mdshunk
Senior Member
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In old work, it does sometimes glow on the neutral. There was a period of time when switching the neutral was favored. When the switch is off, and a lamp is installed in the lampholder, the hot and the neutral to the lampholder will make your sniffer glow.
voltage
voltage
I know at some point it is all going to snap and make since to me. I'm pictureing a 120 circuit going to a light. The circuit is on and light is lit. The voltage goes back and forth 60 times a second. I'm pictureing the voltage going from the hot conductor through the resistance back to the source on the neutral conductor and back. Wouldn't the neutral conductor have a voltage on it. You have voltage on two legs makeing 208 in a three phase system. The only diff with 120 is the center tap.
voltage
frizbeedog said:Just wondering. How do you measure voltage on the grounded conductor?
It's a volt stick. Not a current stick. It detects voltage.
Lift that neutral and then it will work.
I know at some point it is all going to snap and make since to me. I'm pictureing a 120 circuit going to a light. The circuit is on and light is lit. The voltage goes back and forth 60 times a second. I'm pictureing the voltage going from the hot conductor through the resistance back to the source on the neutral conductor and back. Wouldn't the neutral conductor have a voltage on it. You have voltage on two legs makeing 208 in a three phase system. The only diff with 120 is the center tap.
Think of it this way: You have two conductors, technically called the ungrounded (hot) and the grounded (neutral).
The ungrounded has a voltage potential in relationship to ground. The grounded does not, because, well.... it's grounded.
Another analogy is a sink. The water coming out of the faucet is under pressure, but the same amount of water going down the drain is not. (OK, not a perfect example, and yes, the water in the drain has some pressure, but if it helps the OP understand....)
The ungrounded has a voltage potential in relationship to ground. The grounded does not, because, well.... it's grounded.
Another analogy is a sink. The water coming out of the faucet is under pressure, but the same amount of water going down the drain is not. (OK, not a perfect example, and yes, the water in the drain has some pressure, but if it helps the OP understand....)
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480sparky said:
I agree, the volt stick looks for a difference of potential between the circuit conductor and ground.
No different then using a wiggy from ground to a neutral that is in use and complete. The wiggys will not show any voltage even though the we know current is flowing in it.
There is a similar device that detects current rather than voltage. I don't know how well it actually works.
mdshunk
Senior Member
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There's an interesting gizmo. I'm trying to figure out how that would be useful. Any ideas?steved said:
- Location
- Massachusetts
mdshunk said:
Might be able to check electrical heating elements for opens.
Of course you would have to be careful not to forget this units limitations.
winnie
Senior Member
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- Springfield, MA, USA
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- Electric motor research
Try thinking about it this way: rather than saying that the volt tick detects voltage on the wire, or voltage between the wire and _ground_, say that the volt tick detects voltage between the wire and your hand.
No imagine that you are a like a bird standing on a wire. You reach the volt tick over to one of the _other_ wires, and it registers. But when you reach down and bring the volt tick over to the wire that you are standing on, it does not register.
With the 'neutral' or 'grounded conductor', you are in a similar situation. There is still 'voltage' on the wire, and current flowing through it, but the earth is attached to that wire. The earth, your hand, the body of the volt tick are all at the _same_ voltage (or similar enough voltage) that the volt tick has no voltage _difference_ to detect.
-Jon
No imagine that you are a like a bird standing on a wire. You reach the volt tick over to one of the _other_ wires, and it registers. But when you reach down and bring the volt tick over to the wire that you are standing on, it does not register.
With the 'neutral' or 'grounded conductor', you are in a similar situation. There is still 'voltage' on the wire, and current flowing through it, but the earth is attached to that wire. The earth, your hand, the body of the volt tick are all at the _same_ voltage (or similar enough voltage) that the volt tick has no voltage _difference_ to detect.
-Jon
dbuckley
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cschmid
Senior Member
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- Northern cold country
dbuckley said:
Thanks man I like...
mivey
Senior Member
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
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- Electrical Contractor
Jake, even though you said you got it, I'd like to add a little more.Jakewhis said:
Non-contact testers sense voltage (relative to earth) on the wire, and not current flowing through the wire. Voltage drops aside, no, the neutral does not have voltage on it, but yes, the neutral does carry the same current as the hot.
When it comes to testing and troubleshooting,voltmeters, solenoid testers, and non-contact testers each have their place. For example, I reserve the typical high-impedance voltmeter for when I need to know the exact voltage.
For most troubleshooting, the solenoid tester is my #1 choice, because it provides enough of a load to eliminate induced voltages, which fool most of the other types. A non-contact tester is best for detecting shock hazards.
You need to know when there's a voltage difference between two conductors and when there's a voltage on a wire relative to the earth. An open neutral can show no voltage bewteen it and the hot, but they can still be hot to earth.
cschmid
Senior Member
- Location
- Northern cold country
dbuckley said:
Man I got to become a better sales man I have never been able to talk that many people into doing that..might have to get camera and film some research..maybe find some green horns to try that..:grin: :grin: do I have any volunteers for an experiment with an electric fence..:grin:
76nemo
Senior Member
- Location
- Ogdensburg, NY
There are several current sensors on the market, but I have yet to figure out they work.
There is a MythBusters on this week with one of those fellas urinating on a fence. I am sure it will be a crock, and we won't see the settings of the supply. Man, some of those old ones, you can really vamp up:grin:
At one of my jobs in NC, my boss was petrified of electricity. He was an ACE mechanic, would jump right in on motor work, conveyors, etc.. I couldn't find the nerve to ask him why he feared it so much. One day I did. He said he was rabbit hunting with his uncle many years ago who was about 100 yards away or so. When he came to the fence, he placed his rubber butt stock to the wire, pushed it to the ground and proceeded to pass. Half way over, the gun tilted, freeing the wire and finding a home in his groin. It was vamped enough he threw his gun, and fell to the ground. Well, ever time he would recover and stand up, it pulsed just right and would floor him again. Back down he went. I think it was either 2-3 pulses, but now I knew why he would go down another aisle if I had a panel open:grin: Poor guy
There is a MythBusters on this week with one of those fellas urinating on a fence. I am sure it will be a crock, and we won't see the settings of the supply. Man, some of those old ones, you can really vamp up:grin:
At one of my jobs in NC, my boss was petrified of electricity. He was an ACE mechanic, would jump right in on motor work, conveyors, etc.. I couldn't find the nerve to ask him why he feared it so much. One day I did. He said he was rabbit hunting with his uncle many years ago who was about 100 yards away or so. When he came to the fence, he placed his rubber butt stock to the wire, pushed it to the ground and proceeded to pass. Half way over, the gun tilted, freeing the wire and finding a home in his groin. It was vamped enough he threw his gun, and fell to the ground. Well, ever time he would recover and stand up, it pulsed just right and would floor him again. Back down he went. I think it was either 2-3 pulses, but now I knew why he would go down another aisle if I had a panel open:grin: Poor guy
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
A local realtor is a bit accident prone, and in addition to flogging homes he's a pretty decent polo player. There he was one day in his paddock, on his horse, and it chucked him off onto the electric fence. Not only did the fall break bones (ow!) but there he was lying on the floor getting belted every second by the fence causing him to move and aggravate the orthopedic injuries... (this is the same fence my missus sampled, just once)
He recovered from that, only for him to lose control of his SUV going round a corner, crashing into and taking out a power pole (11KV and 33KV), so taking our township's power out for a few hours, whilst breaking his pelvis and a few other bits.
Like I said; accident prone...
You don't wanna pee onto an electric fence. Mythbusting not required. Of course, in many places in the world their electric fences are quite wimp, some regulation or other limiting their power. But here in New Zealand, birthplace of the electric fence, we have proper electric fences, and you really don't want to touch one at all...
He recovered from that, only for him to lose control of his SUV going round a corner, crashing into and taking out a power pole (11KV and 33KV), so taking our township's power out for a few hours, whilst breaking his pelvis and a few other bits.
Like I said; accident prone...
You don't wanna pee onto an electric fence. Mythbusting not required. Of course, in many places in the world their electric fences are quite wimp, some regulation or other limiting their power. But here in New Zealand, birthplace of the electric fence, we have proper electric fences, and you really don't want to touch one at all...
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