anyone who thumbs down this video doesn't appreciate a great instructional video, I'm an electrician of over 20 years and I've never see it described this way and it's amazing. Bravo!
Very good basic video presenting ungrounded power on shipboard applications. However, in today's environment, these types of ground fault detectors have been replaced with insulation resistance monitors that monitor the insulation resistance level from your three-phases relative to ground (hull). Main reasons for using insulation monitors instead of "ground detector circuits" include the fact that most AC systems are not only "resistive" and the fact that the capacitance to ground on a shipboard application can be very high and effect the sensitivity of the detection of the ground fault. There are even products now available that can locate the faulty circuit without having to switch loads on and off.
+rory johnstone there are a couple of companies the manufacture earth/ground fault detection in ungrounded electrical systems. Bender Electronics, bender.org, has a good overview.
Just because it looks like bare metal does not mean there is no insulation designed into the system somehow, and furthermore this guy clearly is using this thing as an instructional aide rather than some kind of installation at a job site where someone might get hurt. He even went out of his way to mention that he taped off the exposed male prong end of the left side Y that he hooked up, so obviously he is aware of the importance of insulation. Seriously this video is maybe one of the best instructional pieces I have ever found on the internet and I do not think that your looking for a reason to find fault (pun intended) with this video will serve anyone watching it.
we have a ship panel with a analog gfd gauge, have not had any readings until this year, shows 2-4amp, when pushing the button, goes down to less than 1 On generator power, no fault shows at all one of the chargers makes a buzzing noise, again,not under gen power any ideas what we have going on ? Thanks Guy
I have question maybe you can help me please?? I have a 300/400 foot run of #2 awg quadplex with a messenger its comes from a 4160 switch to another switch. I have isolated both ends and am trying to find out if the cable is ok? Each phase shows a short to ground but no shorts phase to phase? It makes no sense to me? I'm baffled as are many other electricians I pose this question to? This cable is in a steel mill and there are a lot of high voltage lines above this run to where i can put a tick tracer in the air and it goes off? I'd appreciate any kind of support for this question!! Thank you for your time and excellent presentation!! jim
Hi, Thanks for the video. I have a question about your demonstration rig. Since you have shorted a phase to ground why don't you blow a fuse for over current? Is there a resistor in your ground bus?
The ground bar is at the same potential as the phase it's shorted to and the ground bar is attached to nothing else. If the ground was hooked to say a wye secondary transformer feeding the phases, then it would require a fuse or breaker to break the fault current.
Question. When you take the WYE of the fault detector and land it to the haul/ground wouldn't this energize the haul with 69VAC? Also, when phase C was at the same potential as the neutral of the detector you drew a line to phase C. This wouldn't physically happen obviously, so where exactly is the connection happening to allow 120VAC across the other other two lights. Doesn't make sense
Scott Andrew what is your qualifications in electrical systems? 1st question, no this is an AC system and 69V is the RMS phase voltage. For a balanced 3 phase system, when phase A and B are a positive value, phase C is the summation of these but negative, equating all 3 phases to 0V which is the neutral point 2nd question, for a phase C to ground fault, ground becomes the potential of C and therefore shorting out the C bulb, hence why it goes off (no current flow). Ground is connected to neutral and therefore the neutral becomes the potential of C so phase A and B are effectively connected to phase C, which has a L-L RMS value of 120V... Hope this answers your questions?
Scott Andrew sounded like that's what you're asking... rephrase it then? And if you have a Masters in EE, I'd expect you to understand this stuff... I'm a chartered engineer with a Masters in E&EE... this stuff he's doing is simple circuit theory, if it doesn't make sense, I'd suggest you go back to uni 😂
Scott Andrew no worries bro! Glad we cleared that up! Always remember AC circuits isn't a constant voltage, sometimes this throws people off 😊 happy to help
anyone who thumbs down this video doesn't appreciate a great instructional video, I'm an electrician of over 20 years and I've never see it described this way and it's amazing. Bravo!
![4 of 7 Grounded Versus Ungrounded System, NEC 2014 - [100], (35min:35sec)](/img/n.gif)
anyone who thumbs down this video doesn't appreciate a great instructional video, I'm an electrician of over 20 years and I've never see it described this way and it's amazing. Bravo!
👍👍👍
basically explaining IT grounding! Very nice!
Excellent description, I am showing it to my students. That is a nice circuit simulation. Thanks
This is an awesome video I’ve been an MEBA member for 4 1/2 years. I can’t wait to make it back to the Calhoun school
thts really some brilliant demonstration.. made my day..Thankyou Sir
Thank you very much for explaining about ground fault.
I'm expecting your new videos.
Great description, shows why if your rcd only monitors neutral current an men must be fitted
Thank you for perfect explanations
You're a boss ,great explanation
Great demonstration! Thank you
Very good basic video presenting ungrounded power on shipboard applications. However, in today's environment, these types of ground fault detectors have been replaced with insulation resistance monitors that monitor the insulation resistance level from your three-phases relative to ground (hull). Main reasons for using insulation monitors instead of "ground detector circuits" include the fact that most AC systems are not only "resistive" and the fact that the capacitance to ground on a shipboard application can be very high and effect the sensitivity of the detection of the ground fault. There are even products now available that can locate the faulty circuit without having to switch loads on and off.
+Joseph Boardman What are the names of the products that can locate earth faults without switching on and off loads?
+rory johnstone there are a couple of companies the manufacture earth/ground fault detection in ungrounded electrical systems. Bender Electronics, bender.org, has a good overview.
+Joseph Boardman Thank you for this information.
Very good explanation sir Thank you..
This is such a gem of a video! Thank you for making it so comprehensive. Is ground fault monitoring applicable for DC power sources as well?
Great video!
Thank u sir very nice explanation
AMAZING!!!!!
We use these on Navy ships for 120VAC and 440VAC circuits.
Outstanding
Thanks for the video. What happens to the voltage in delta if one phase goes to earth?
thank you sir!
Brilliant
very helpful
Thanks for the video, good description. you should insulate those buss bars for safety tho!
Just because it looks like bare metal does not mean there is no insulation designed into the system somehow, and furthermore this guy clearly is using this thing as an instructional aide rather than some kind of installation at a job site where someone might get hurt. He even went out of his way to mention that he taped off the exposed male prong end of the left side Y that he hooked up, so obviously he is aware of the importance of insulation. Seriously this video is maybe one of the best instructional pieces I have ever found on the internet and I do not think that your looking for a reason to find fault (pun intended) with this video will serve anyone watching it.
we have a ship panel with a analog gfd gauge, have not had any readings until this year, shows 2-4amp, when pushing the button, goes down to less than 1
On generator power, no fault shows at all
one of the chargers makes a buzzing noise, again,not under gen power
any ideas what we have going on ?
Thanks
Guy
I have question maybe you can help me please?? I have a 300/400 foot run of #2 awg quadplex with a messenger its comes from a 4160 switch to another switch. I have isolated both ends and am trying to find out if the cable is ok? Each phase shows a short to ground but no shorts phase to phase? It makes no sense to me? I'm baffled as are many other electricians I pose this question to? This cable is in a steel mill and there are a lot of high voltage lines above this run to where i can put a tick tracer in the air and it goes off? I'd appreciate any kind of support for this question!! Thank you for your time and excellent presentation!! jim
Hi, Thanks for the video. I have a question about your demonstration rig. Since you have shorted a phase to ground why don't you blow a fuse for over current? Is there a resistor in your ground bus?
The ground bar is at the same potential as the phase it's shorted to and the ground bar is attached to nothing else. If the ground was hooked to say a wye secondary transformer feeding the phases, then it would require a fuse or breaker to break the fault current.
Excellent video - I've posted your video in my resources section of jotbud.com! This is very helpful for electrical apprentices
Sir when phase touches the earth, it means earth will come at earths potential ?
WHAT HAPPENS IN THE DELTA CONNECTION
Questions: When he pushes the button how is the C to Ground negated, but there is still power in the system?
The pushbutton breaks connection from the ground to the center tap of the wye configuration.
So are you bringing the ground to C phase potential or C phase to ground potential?
yes
Dear Sir i want your mail id need for more queries regarding 3 phase earth fault issue. I wanted discuss one more idea.
Question. When you take the WYE of the fault detector and land it to the haul/ground wouldn't this energize the haul with 69VAC?
Also, when phase C was at the same potential as the neutral of the detector you drew a line to phase C. This wouldn't physically happen obviously, so where exactly is the connection happening to allow 120VAC across the other other two lights. Doesn't make sense
Scott Andrew what is your qualifications in electrical systems?
1st question, no this is an AC system and 69V is the RMS phase voltage. For a balanced 3 phase system, when phase A and B are a positive value, phase C is the summation of these but negative, equating all 3 phases to 0V which is the neutral point
2nd question, for a phase C to ground fault, ground becomes the potential of C and therefore shorting out the C bulb, hence why it goes off (no current flow). Ground is connected to neutral and therefore the neutral becomes the potential of C so phase A and B are effectively connected to phase C, which has a L-L RMS value of 120V...
Hope this answers your questions?
Scott Andrew sounded like that's what you're asking... rephrase it then? And if you have a Masters in EE, I'd expect you to understand this stuff... I'm a chartered engineer with a Masters in E&EE... this stuff he's doing is simple circuit theory, if it doesn't make sense, I'd suggest you go back to uni 😂
Peter Killeen no no you answered my question perfectly!! Thank you very much! When I replied I was replying to the wrong post.
Scott Andrew no worries bro! Glad we cleared that up! Always remember AC circuits isn't a constant voltage, sometimes this throws people off 😊 happy to help
isn't the system 208/120v? so wouldn't one get 208v phase-phase?
Ohhhh I get it
anyone who thumbs down this video doesn't appreciate a great instructional video, I'm an electrician of over 20 years and I've never see it described this way and it's amazing. Bravo!