When measuring the voltage on the neutral with a lost or open neutral where are you taking the the measurement from on the three wires .Where are the test leads on your setup .it does make a difference .this could leave a state of confusion as to where the connectios are made. Thanks for the video
@@jim-cu9yp I’m measuring the voltage between what was the branch neutral, and the actual neutral wire that runs back to the 240 V receptacle for my oven. The branch neutral is obviously no longer actually the neutral. It is essentially now just the wire that ties the two legs together into a series circuit. I hope this makes sense how I’m explaining it.
How does the earthed grounding rod the panel is bonded to factor into this issue . .if you now have voltage on the Neutral and its also bonded to the Grounding rod ?. I do understand there will be restance in the ground path as its not going to be a perfect low restance connection to the center tap of the power companys supply transformer.
Yes, the earth is actually a very poor conductor of electricity, so it really does not provide a path back to the ground/neutral from the transformer. With voltage on the ground and/or neutral bus in the panel, you will have a little bit of current flowing through the grounding electrode conductor and to the ground rod, but since it is such a low impedance path, I think you will have less than 3 or 4 Amps of current so I think it’s effect is almost negligible.
@@morganinspectionservices3840 so what is the point of a ground rod (specifically how does it help with issues arising from the home itself not say lightning)? I always thought ground faults traveled thru the ground bus and into the ground rod but I was recently told THIS IS FALSE! Help?!
I have a question about lost neutral. I had this happen. Electric company had to replace electric supply to my home. Power cables run under the street. No above ground supply. I know I am at the end of the circuit for the neighborhood, due to power outages during hurricanes in the past. I lost several electrical items in the home due to this. Whole home surge protector showed evidence of burning, cracked open and black. Siding on home showed area of black, like scolding from the electrical panel and grounding box. Per electrical engineer electrical panels for home replaced due to the events of the lost neutral. Bus bars were no longer shiny, they were discolored. I replaced the panels as I was informed that THEY HAD TO BE REPLACED DUE TO THE BAD NEUTRAL and the transient spike. Is this true?
Hi. I will have to defer to the expert on this one. The electrical engineer made that call. I cannot say he was wrong. I will say that this is first time that I have heard of a panel having to be replaced due to a lost neutral. It sounds like a lot of damage was caused in your situation so it probably was necessary. I am familiar with a dozen or so lost neutrals occurring to various people who I know, and this extreme measure was not necessary in any of those cases.
Yes, the current on the neutral is the difference between the currents on the two legs. My intention was not to teach all that, but to show what happens with a lost neutral.
Friend - not to ask another question (when I didn’t even give you a chance to respond to my two question posts on the original video), but I have to ask you: I learned in school that for current to flow, we need a circuit, a loop, now if the load is balanced, and no electrons are flowing thru neutral back to transformer, then how is electricity able to flow at all if there is no loop/circuit?! Don’t the electrons block one another on either side of the neutral and thus stop all electricity?! PLEASE PLEASE unpack this for me! I’m mentally stuck and I really want to move past the 4 min mark in the video !!!
Hi. I appreciate the questions. I appreciate the fact that you’re watching my videos. The electrons do not block each other. While one side of the transformer is “pushing” electrons, the other side of the transformer is “pulling” electrons. That’s how 240 V circuits work. It’s kind of a push You, pull me sort of thing. They are not pushing against each other, but they are working together. One pushes, the other pulls. Then it reverses. 60 times per second.
@@morganinspectionservices3840 But in your video you mention at 3:50 that there are no electrons flowing on the neutral back to transformer when the system is fully balanced: but how could electricity flow in this scenario if there is no loop/continuous circuit ? Wouldn’t it need to continue on thru the neutral into transformer? I always learned electricity needs a potential difference and a loop. How is your system violating thing yet still flowing?
@ When you are talking about a 120 volt circuit, then yes, you must have a neutral to have a continuous loop. A 240 v circuit does not need a neutral to have a loop or a closed circuit. The two separate 120 volt circuits (one at +120, and the other at -120, make up the closed loop. This is how an electric oven, water heater, AC work. No neutral.
But what confuses me is - the two hot legs in your diagram in a fully balanced system show the hot legs only having current going away from the transformer not one going in and one going out ! So how is there a loop?
A very good explanation of the problem. The very first time you come across this issue, it will take a minute to understand what you are seeing. Happens often after a storm.
When measuring the voltage on the neutral with a lost or open neutral where are you taking the the measurement from on the three wires .Where are the test leads on your setup .it does make a difference .this could leave a state of confusion as to where the connectios are made. Thanks for the video
@@jim-cu9yp I’m measuring the voltage between what was the branch neutral, and the actual neutral wire that runs back to the 240 V receptacle for my oven. The branch neutral is obviously no longer actually the neutral. It is essentially now just the wire that ties the two legs together into a series circuit. I hope this makes sense how I’m explaining it.
How does the earthed grounding rod the panel is bonded to factor into this issue . .if you now have voltage on the Neutral and its also bonded to the Grounding rod ?. I do understand there will be restance in the ground path as its not going to be a perfect low restance connection to the center tap of the power companys supply transformer.
Yes, the earth is actually a very poor conductor of electricity, so it really does not provide a path back to the ground/neutral from the transformer. With voltage on the ground and/or neutral bus in the panel, you will have a little bit of current flowing through the grounding electrode conductor and to the ground rod, but since it is such a low impedance path, I think you will have less than 3 or 4 Amps of current so I think it’s effect is almost negligible.
@@morganinspectionservices3840 so what is the point of a ground rod (specifically how does it help with issues arising from the home itself not say lightning)? I always thought ground faults traveled thru the ground bus and into the ground rod but I was recently told THIS IS FALSE! Help?!
I have a question about lost neutral. I had this happen. Electric company had to replace electric supply to my home. Power cables run under the street. No above ground supply. I know I am at the end of the circuit for the neighborhood, due to power outages during hurricanes in the past. I lost several electrical items in the home due to this. Whole home surge protector showed evidence of burning, cracked open and black. Siding on home showed area of black, like scolding from the electrical panel and grounding box. Per electrical engineer electrical panels for home replaced due to the events of the lost neutral. Bus bars were no longer shiny, they were discolored. I replaced the panels as I was informed that THEY HAD TO BE REPLACED DUE TO THE BAD NEUTRAL and the transient spike. Is this true?
Hi. I will have to defer to the expert on this one. The electrical engineer made that call. I cannot say he was wrong. I will say that this is first time that I have heard of a panel having to be replaced due to a lost neutral. It sounds like a lot of damage was caused in your situation so it probably was necessary. I am familiar with a dozen or so lost neutrals occurring to various people who I know, and this extreme measure was not necessary in any of those cases.
4:46 That does nit really tell it correctly as it shows the sum of the currents in the neutral when it is the difference.
Yes, the current on the neutral is the difference between the currents on the two legs. My intention was not to teach all that, but to show what happens with a lost neutral.
Friend - not to ask another question (when I didn’t even give you a chance to respond to my two question posts on the original video), but I have to ask you: I learned in school that for current to flow, we need a circuit, a loop, now if the load is balanced, and no electrons are flowing thru neutral back to transformer, then how is electricity able to flow at all if there is no loop/circuit?! Don’t the electrons block one another on either side of the neutral and thus stop all electricity?! PLEASE PLEASE unpack this for me! I’m mentally stuck and I really want to move past the 4 min mark in the video !!!
Hi. I appreciate the questions. I appreciate the fact that you’re watching my videos. The electrons do not block each other. While one side of the transformer is “pushing” electrons, the other side of the transformer is “pulling” electrons. That’s how 240 V circuits work. It’s kind of a push You, pull me sort of thing. They are not pushing against each other, but they are working together. One pushes, the other pulls. Then it reverses. 60 times per second.
@@morganinspectionservices3840
But in your video you mention at 3:50 that there are no electrons flowing on the neutral back to transformer when the system is fully balanced: but how could electricity flow in this scenario if there is no loop/continuous circuit ? Wouldn’t it need to continue on thru the neutral into transformer? I always learned electricity needs a potential difference and a loop. How is your system violating thing yet still flowing?
@ When you are talking about a 120 volt circuit, then yes, you must have a neutral to have a continuous loop. A 240 v circuit does not need a neutral to have a loop or a closed circuit. The two separate 120 volt circuits (one at +120, and the other at -120, make up the closed loop. This is how an electric oven, water heater, AC work. No neutral.
But what confuses me is - the two hot legs in your diagram in a fully balanced system show the hot legs only having current going away from the transformer not one going in and one going out ! So how is there a loop?
A very good explanation of the problem. The very first time you come across this issue, it will take a minute to understand what you are seeing. Happens often after a storm.
Thank you.
i k szs@@morganinspectionservices3840