Open Service Neutral GFCI/RCD Detector

[tersh]

https://www.mikeholt.com/mojonewsarchive/NEC-HTML/HTML/DangerofOpenServiceNeutral~20020816.htm


"If the grounded (neutral) service conductor is opened or not provided at all, objectionable neutral current will flow on metal parts of the electrical system and dangerous voltage will be present on the metal parts providing the potential for electric shock"

The utility company told me this is the main reason we omitted the use of neutral and 120v in the Philippines even when USA designed our power system with similar centertap configuration because we don't have the discipline to follow all the codes. And the death from open service neutral can be more than ground fault electrocution. It's not because its illegal to use 120v but more of safety.

So I avoided using 120v too in my parents house (most switching adaptors in most gadgets nowadays and even entertainment units like TV or home theater use universal 100-240v so anyone can use in any part of the world).

Yesterday I realized we have one 120v unit installed that I didn't consider before! In our commercial building, we have full 3-wire so have access to the neutral in the service entrance and main panel. And Equipment Grounding Conductor and stuff is readily available. All my questions before is related to my parents home where there is no 3-wire in the entire townhouse compound with other 5 houses. Many new commercial building are 3 wire but not normal homes.

I bought a Siemens First Surge 140,000A Surge protector a few months back after a 65 year old EE advised me how to use it locally, and installed it in the commercial building.

https://www.amazon.com/Siemens-FS14...F8&qid=1544142905&sr=8-1&keywords=first+surge

The above was the Siemens First Surge installed in a subpanel with bolt-on breakers. It was just temporary setup. The proper way is to install it at the right side so the ground/neutral leads would be as short as possible.
Now here is the problem.

If the service neutral becomes open or disconnected. The electricity will reach all the metal enclosure in the building because the neutral and ground is bonded at the main panel (My connection in the office building is USA style with centertapped grounded neutral connected to the building and bonded with ground once and 120v, 240v available). This is how I power the Siemens First Surge which require 120v to operate and not 240v or it would burst into flame.

Now can you think of ways to integrate GFCI or RCD so that if the neutral got disconnected, the Siemens First Surge would lose power?

I saw someone make an open service neutral detector:

https://www.thaivisa.com/forum/topic/457002-the-hazard-of-an-open-circuit-neutral/

Or without reading them. Just imagine the neutral part of the toroid differential circuit, if the neutral got disconnected.. think of a way it can disconnect the circuit by right connections of them all.

Ok to use isolation transformer in conjunction with the SPD and GFCI/RCD. But I have to make sure the unique connections will work and verifying with many before letting the master qualified electrician install any.
Thank a lot.

 

[tersh]

Btw.. this is not paranoia. Look at this service entrance neutral in our residence hanging by a thread:

It can get disconnected by hurricane etc. So open service neutral is a common occurrence in the country. Now look at this Siemens First Surge, it has 120v circuitry inside like the lamp...

In the event the neutral is disconnected. All the metal chasis in the building would be electrified. So I need to find ways to disconnect it if the neutral got disconnected. Any idea how? If there is absolutely no solution, then I'd just remove the Siemens First Surge and and not use it anymore. Equipment damage is more tolerable than human damage.

In the entire USA. Are there no commercial products precisely to address this concern?

 

[tersh]

Btw.. this is my last thread, so have patience all those who have helped me... let's tackle this last subject.

"How it works. Consider normal operation (top diagram), the neutral is at or near ground potential so no current flows down the ground stake and the RCD remains in balance. Open the neutral (second diagram), now there is no current in the neutral leg of the RCD and it opens protecting your supply. Reverse phase and neutral (third diagram) and we have a similar effect, again the RCD is imbalanced and trips."

What is a ground stake? How does it work in single phase?
​

I don't have a clue how the above RCD can detect open service neutral. Does it also disconnect the 120v circuits?

It originated in Africa because of often stolen neutral.

https://www.thaivisa.com/forum/topic/457002-the-hazard-of-an-open-circuit-neutral/

Any in the US has created some circuits to address it?

 

[winnie]

If you have ground(bonded metal)/neutral bonding in a service, and if you lose the service neutral, _and_ if you have line-neutral loads, then the current through the line-neutral loads will energize the bonded metal.

If you do not have line-neutral loads then there is nothing to energize the bonded metal.

If the only line-neutral load is this surge protective device, then the first question I would ask is what is the maximum neutral current it can pass. Because this is the maximum current available to energize things in an open neutral situation. If the max neutral current is lower than what would cause harm, then do you need to protect against that fault?

In an open neutral scenario, for the building neutral and bonded metal to become energized, the line-neutral voltage balance has to change. So you use a relay which detects this change to open a shunt trip breaker. If the neutral opens but because of the connected loading the line-neutral balanced does not change, then you don't detect the open neutral, but it also doesn't cause a problem

-Jon

 

[winnie]

I don't have a clue how the above RCD can detect open service neutral. Does it also disconnect the 120v circuits?

The RCD doesn't detect the open neutral.

Instead the open neutral makes it possible for the internal building neutral voltage to change. How much this voltage changes depends on the connected loads. If the connected loads are only line-line, or are perfectly balanced, then the internal neutral voltage doesn't change.

If the internal neutral voltage does change, then current will flow on the buiding's ground rod. This is current returning to the transformer but not through the service conductors, and thus 'residual current'. This residual current is what the RCD detects.

So the open neutral makes possible (but does not guarantee) residual current, and the RCD detects this current.

-Jon

 

[tersh]

If you have ground(bonded metal)/neutral bonding in a service, and if you lose the service neutral, _and_ if you have line-neutral loads, then the current through the line-neutral loads will energize the bonded metal.

If you do not have line-neutral loads then there is nothing to energize the bonded metal.

If the only line-neutral load is this surge protective device, then the first question I would ask is what is the maximum neutral current it can pass. Because this is the maximum current available to energize things in an open neutral situation. If the max neutral current is lower than what would cause harm, then do you need to protect against that fault?

In an open neutral scenario, for the building neutral and bonded metal to become energized, the line-neutral voltage balance has to change. So you use a relay which detects this change to open a shunt trip breaker. If the neutral opens but because of the connected loading the line-neutral balanced does not change, then you don't detect the open neutral, but it also doesn't cause a problem

-Jon

For USA power system, can you share any schematic of this relay that you used? or any link or references about such devices for your single phase 3-wire split phase 120/240v home ac system?

Any installation will be done by qualified electrician, don't worry.

 

[winnie]

For USA power system, can you share any schematic of this relay that you used? or any link or references about such devices for your single phase 3-wire split phase 120/240v home ac system?

Any installation will be done by qualified electrician, don't worry.

I've not used such relays.

A google search for neutral loss detection relay turns up several possibilities, but I don't have any basis for making a recommendation.

The relay that we use in our lab is residual current detection only, and then at the 1-10A level for equipment protection, not what you are looking for.

I will repeat, before chasing down open neutral protection, you should find out exactly what damage an open neutral would cause for your equipment. If the only load tied to neutral is the surge protector, then you should find out from the manufacturer what happens in an open neutral scenario.

-Jon

 

[kwired]

I think if you want to protect from "open neutral" you maybe need to have a over/under voltage relay(s) and use it to drive shunt trip coil on a breaker or to drop out a main contactor any time the relay detects voltage issues.

 

[RumRunner]

Ok to use isolation transformer in conjunction with the SPD and GFCI/RCD. But I have to make sure the unique connections will work and verifying with many before letting the master qualified electrician install any.
Thank a lot.

ii

This is an interesting pictorial diagram. The “trip circuit” module is powered by the toroid XFMR and in turn drives a relay (solenoid) TC.

This relay closes the two contacts designated “23” and “24”. These contacts enable the primary and thus provide power to the secondary via “17” and “18”.

So the feedback signal is obviously coming from “26” and “27”.
A detected ground fault (or open Neutral) is processed by the module and energizes TC which has normally open contacts.

All the functionalities of this “supposedly”magic bullet don't quite add up.

And here is the RUB:

How are you going to have this system operate when the TC (solenoid) needs power to close the contacts-- when there is no power going the Primary.

The logic behind-- where everything started according to the GENESIS:

In the beginning there was total darkness, and then, the Divine Providence gave us light when he said;“Let there be light.” And voila there was light but there was still nothing. He created a lot of things and rested, (I guess the job needed a lot of work.). . . even the divine power needed to take a rest. :happyyes:

Perhaps we will have to invoke the “Big Bang Theory” if the Genesis doesn't offer an explanation.


Thoughts?

 

[tersh]

ii

This is an interesting pictorial diagram. The “trip circuit” module is powered by the toroid XFMR and in turn drives a relay (solenoid) TC.

This relay closes the two contacts designated “23” and “24”. These contacts enable the primary and thus provide power to the secondary via “17” and “18”.

So the feedback signal is obviously coming from “26” and “27”.
A detected ground fault (or open Neutral) is processed by the module and energizes TC which has normally open contacts.

All the functionalities of this “supposedly”magic bullet don't quite add up.

And here is the RUB:

How are you going to have this system operate when the TC (solenoid) needs power to close the contacts-- when there is no power going the Primary.

The logic behind-- where everything started according to the GENESIS:

In the beginning there was total darkness, and then, the Divine Providence gave us light when he said;“Let there be light.” And voila there was light but there was still nothing. He created a lot of things and rested, (I guess the job needed a lot of work.). . . even the divine power needed to take a rest. :happyyes:

Perhaps we will have to invoke the “Big Bang Theory” if the Genesis doesn't offer an explanation.


Thoughts?

That image is one I randomly took at internet showing what is a GFCI/RCD. This is in order to inquire what this description mean:

"How it works. ​

Consider normal operation (top diagram), the neutral is at or near ground potential so no current flows down the ground stake and the RCD remains in balance. Open the neutral (second diagram), now there is no current in the neutral leg of the RCD and it opens protecting your supply. Reverse phase and neutral (third diagram) and we have a similar effect, again the RCD is imbalanced and trips."​

This is taken from the thai site:

https://www.thaivisa.com/forum/topic/457002-the-hazard-of-an-open-circuit-neutral/


What does it mean? How do you understand it? Kindly explain how the circuit can detect open service neutral and how you can do it with the USA 120/240v split power ac system.

 

[Adamjamma]

Basically, what the diagrams and notes are both telling you is that in normal operations the RCD or GFCI in the USA, is sensing for an imbalance on the operations... if neutral is lost, it trips. If neutral and live are crossed then it trips... if the amount of neutral returning is not within some design amount, it trips.
Then you have RCBOs, which operate the same but also contain a standard overcurrent device, thus they also trip when current is more than a certain amount.
This is different from AFCI, which will trip if it reads a signal in the neutral to the live that tells it that an arc may have occurred... this operates much in the way a spider senses something on its web... a vibration caused by the arcing trips the sensor, which shuts off the circuit.

now, since you are in effect running 240 volt circuits throughout your home in the Philippines without a neutral or even apparently a ground, it looks like about all you can do is to either have an electrician rewire your home to use a ground of some style, using as you have thought of, RCD or GFCI circuits to try to help out. If I was doing it, every single circuit would get replaces with at least three wire cables, though I would prefer four wire cables instead. Although there is no neutral being supplied by the POCO, from what I have read this weekend, in many parts of your country, I would still wire it based upon the T T type of systems here in the UK, which means trying to get some sort of groundrods at the beginning of theservice, to create the neutral and the ground. Though it is better to run the neutral from the transformers, you can still create your neutral in your home by getting as low a ground point as possible at your panel.
Then once you have the wires and needs figured out you can start to wire safely. I again would run four wires, and would probably use the following colors... black, brown or red, white and green. You would then need to decide what outlets need to be 240 and which ones need to be 120... which also is why a good electrician needs involved. While I can do this, I also have been working in three different countries and am used to the power changes and wiring involved, though I am not certified in any country yet. Thus what info I give you here is not up to code technically. But... the thing to remember is... ifyou can easily and cheaply find appliances and goods that run on 120 then it is rather easy to wire your home for the 120 basedupon what has been posted in several Philippine sites. Because what is supplied to you is two live wires.. both at 120. But for some reason the neutral is not being supplied. As you say, the largest trading partner is Thailand for electronic products so, most of your appliances are less than 15 amp 240 volt two wire appliances. So basically you could use European type outlets or use USA outlets keyed, so you know always which of the two live wires is being used for live.
Again, my own preference in such a case would be to use brown or red for the right incoming line, and treat that as my live on my 240 circuits... and use blue or black as my left incoming line, and treat that as my neutral on 240 circuits. But you have to remember that both are technically live wires.
i would run both a ground and a neutral toevery outlet anyway... in case at a later time you wished to switch from 240 to 120...
i would also use GFCI doublebreakers throughout the installation. This is not cheap but in my own mind necessary. The neutral run to the outlets would not need to be connected to the gfci if you have no 120 circuits but the gfci neutral must be connected within the panel to a neutral strip... since you only have one panel, this would also need bondedto the ground strip. Your electrician should understand and be knowledgeable in this.
should you run any 120 volt circuits, such as in the kitchen, I would try to balance those circuits between the ones using the red live and the ones using the black live... or blue and brown if using those colors, for the live wire used in these areas. I would also note on the outside wether outlets are 120 or 240. So one does notplug a 110v item in a 240 volt outlet. This is the biggest problem one can see in your country as unlike wiring in Jamaica where I use American plugs for 120, and use UK plugs for 240, and thus nothing can be plugged into the wrong plug accidentally because the plugs are too different, in the Philippines the 110 and 240 plugs are identical, due to the source of appliances. So, you must, I repeat, mustlist voltage on the outside of the cover plates if you use both 120 and 240 circuits in your home.
but, if you install just the double breaker gfci breakers, and only have a ground wire to the panel and the neutrals within the panel from the breakers are only wired to the grounding strip and then to the ground that you install, this should give a little more safety compared to what you currently have. However, you MUST remember that technically you are currently using two live wires as live and neutral. Thus, you have no ground or neutral actually in place. You cannot run the wire you call a neutral into the gfci... it will not work. It must be run as a live wire. It will not work in an RCD either, because again, it is sourced from the electric company as a live wire. So it must be treated as a live wire for the gfci or RCD to work. Since double pole RCD is not that common, using a USA panel with GFCI is probably the cheapest option, based upon current pricing.
i also would not bother with trying to run the 100ma RCD in the lead. Given the construction and other problems, I would run the USA standard for gfci, and not mix and match.
To be honest, this is not going to be cheap. The best option for the ground might be toconnect to the rebar in the foundation, and to also add in some extra ground rods should you be able to get deep enough... then to get this bonded to the main panel and to run grounds everywhere possible within your home.
In the area behind the fridge, I would somehow mount a grounding panel that is run back to the main grounding point, for all items in the kitchen to be grounded... this is bonding, not actually grounding, but can be accomplished. Your microwave, if it has been modified for 240 and is not like the label states 120, could be grounded by attaching a wire from the grounding bar behind the fridge to one of the screws on the back of the microwave. Again, a good electrician will know how to do it. A bad electrician will tell you it is not needed and it is not done that way. Since your outlets contain no ground and you want a ground, that is the only way I can see to do it.

 

[tersh]

Basically, what the diagrams and notes are both telling you is that in normal operations the RCD or GFCI in the USA, is sensing for an imbalance on the operations... if neutral is lost, it trips. If neutral and live are crossed then it trips... if the amount of neutral returning is not within some design amount, it trips.
Then you have RCBOs, which operate the same but also contain a standard overcurrent device, thus they also trip when current is more than a certain amount.
This is different from AFCI, which will trip if it reads a signal in the neutral to the live that tells it that an arc may have occurred... this operates much in the way a spider senses something on its web... a vibration caused by the arcing trips the sensor, which shuts off the circuit.

now, since you are in effect running 240 volt circuits throughout your home in the Philippines without a neutral or even apparently a ground, it looks like about all you can do is to either have an electrician rewire your home to use a ground of some style, using as you have thought of, RCD or GFCI circuits to try to help out. If I was doing it, every single circuit would get replaces with at least three wire cables, though I would prefer four wire cables instead. Although there is no neutral being supplied by the POCO, from what I have read this weekend, in many parts of your country, I would still wire it based upon the T T type of systems here in the UK, which means trying to get some sort of groundrods at the beginning of theservice, to create the neutral and the ground. Though it is better to run the neutral from the transformers, you can still create your neutral in your home by getting as low a ground point as possible at your panel.
Then once you have the wires and needs figured out you can start to wire safely. I again would run four wires, and would probably use the following colors... black, brown or red, white and green. You would then need to decide what outlets need to be 240 and which ones need to be 120... which also is why a good electrician needs involved. While I can do this, I also have been working in three different countries and am used to the power changes and wiring involved, though I am not certified in any country yet. Thus what info I give you here is not up to code technically. But... the thing to remember is... ifyou can easily and cheaply find appliances and goods that run on 120 then it is rather easy to wire your home for the 120 basedupon what has been posted in several Philippine sites. Because what is supplied to you is two live wires.. both at 120. But for some reason the neutral is not being supplied. As you say, the largest trading partner is Thailand for electronic products so, most of your appliances are less than 15 amp 240 volt two wire appliances. So basically you could use European type outlets or use USA outlets keyed, so you know always which of the two live wires is being used for live.
Again, my own preference in such a case would be to use brown or red for the right incoming line, and treat that as my live on my 240 circuits... and use blue or black as my left incoming line, and treat that as my neutral on 240 circuits. But you have to remember that both are technically live wires.
i would run both a ground and a neutral toevery outlet anyway... in case at a later time you wished to switch from 240 to 120...
i would also use GFCI doublebreakers throughout the installation. This is not cheap but in my own mind necessary. The neutral run to the outlets would not need to be connected to the gfci if you have no 120 circuits but the gfci neutral must be connected within the panel to a neutral strip... since you only have one panel, this would also need bondedto the ground strip. Your electrician should understand and be knowledgeable in this.
should you run any 120 volt circuits, such as in the kitchen, I would try to balance those circuits between the ones using the red live and the ones using the black live... or blue and brown if using those colors, for the live wire used in these areas. I would also note on the outside wether outlets are 120 or 240. So one does notplug a 110v item in a 240 volt outlet. This is the biggest problem one can see in your country as unlike wiring in Jamaica where I use American plugs for 120, and use UK plugs for 240, and thus nothing can be plugged into the wrong plug accidentally because the plugs are too different, in the Philippines the 110 and 240 plugs are identical, due to the source of appliances. So, you must, I repeat, mustlist voltage on the outside of the cover plates if you use both 120 and 240 circuits in your home.
but, if you install just the double breaker gfci breakers, and only have a ground wire to the panel and the neutrals within the panel from the breakers are only wired to the grounding strip and then to the ground that you install, this should give a little more safety compared to what you currently have. However, you MUST remember that technically you are currently using two live wires as live and neutral. Thus, you have no ground or neutral actually in place. You cannot run the wire you call a neutral into the gfci... it will not work. It must be run as a live wire. It will not work in an RCD either, because again, it is sourced from the electric company as a live wire. So it must be treated as a live wire for the gfci or RCD to work. Since double pole RCD is not that common, using a USA panel with GFCI is probably the cheapest option, based upon current pricing.
i also would not bother with trying to run the 100ma RCD in the lead. Given the construction and other problems, I would run the USA standard for gfci, and not mix and match.
To be honest, this is not going to be cheap. The best option for the ground might be toconnect to the rebar in the foundation, and to also add in some extra ground rods should you be able to get deep enough... then to get this bonded to the main panel and to run grounds everywhere possible within your home.
In the area behind the fridge, I would somehow mount a grounding panel that is run back to the main grounding point, for all items in the kitchen to be grounded... this is bonding, not actually grounding, but can be accomplished. Your microwave, if it has been modified for 240 and is not like the label states 120, could be grounded by attaching a wire from the grounding bar behind the fridge to one of the screws on the back of the microwave. Again, a good electrician will know how to do it. A bad electrician will tell you it is not needed and it is not done that way. Since your outlets contain no ground and you want a ground, that is the only way I can see to do it.

Thanks for such details. But some corrections I need to point out.

1. If you disable a GFCI neutral at source. It won't trip. In the case of the Siemens QF230A 2-pole breaker. The internal circuitry power just turn off and the GFIC won't trip. A GFCI only senses in balance at the output. If you disconnect any of the input. The power just turns off.

2. Second. Why do you refer to the black and red line as 120v each. Actually it's whole phase 240v. You only make it 120v if you measure with respect to the centertap.

3. Third. I really don't have appliances for 120v. Just 120v Surge Protection Device which can be connected to step down transformers.

4. I'm just curious how the open service neutral detector/disconnection for US power system can work. There seems to be none that actually works.

5. Please share list of countries like the Philippines where grounding is not actually used (how about China?), and city hall inspectors never focus on grounding since our appliances don't have grounding.

Thanks for the long messages. Appreciate all the details but millions of homes have no grounding nor ground rods nor neutral/ground conductor to centertap. Did you notice this makes our homes more isolated electrically (and if floor is wooden, no return path back to pole ground rod). I want to see how many countries are like us.

 

[ptonsparky]

Thanks for such details. But some corrections I need to point out.

1. If you disable a GFCI neutral at source. It won't trip. In the case of the Siemens QF230A 2-pole breaker. The internal circuitry power just turn off and the GFIC won't trip. A GFCI only senses in balance at the output. If you disconnect any of the input. The power just turns off.

2. Second. Why do you refer to the black and red line as 120v each. Actually it's whole phase 240v. You only make it 120v if you measure with respect to the centertap.

3. Third. I really don't have appliances for 120v. Just 120v Surge Protection Device which can be connected to step down transformers.

4. I'm just curious how the open service neutral detector/disconnection for US power system can work. There seems to be none that actually works.

5. Please share list of countries like the Philippines where grounding is not actually used (how about China?), and city hall inspectors never focus on grounding since our appliances don't have grounding.

Thanks for the long messages. Appreciate all the details but millions of homes have no grounding nor ground rods nor neutral/ground conductor to centertap. Did you notice this makes our homes more isolated electrically (and if floor is wooden, no return path back to pole ground rod). I want to see how many countries are like us.

2. You have a grounded system. It has been grounded or earthed at the utility’s pole. It Does not matter if you have a grounded current carrying conductor at your home. The hots will be 240 volt between them and 120 volt to earth.

 

[kwired]

2. You have a grounded system. It has been grounded or earthed at the utility’s pole. It Does not matter if you have a grounded current carrying conductor at your home. The hots will be 240 volt between them and 120 volt to earth.

To take that further, someone needs to get the POCO on board with utilization or utilization on board with POCO. Doesn't make sense to ground a point in a system then never take that grounded conductor or any bonding to it beyond the source. If everyone is using 240 volt appliances why don't they ground one line of the 240 volts and forget the center tap? That would make it like it is in most of Europe, then use switchgear like they use there as well instead of 120/240 North American gear that isn't designed for such a system.

 

[tersh]

To take that further, someone needs to get the POCO on board with utilization or utilization on board with POCO. Doesn't make sense to ground a point in a system then never take that grounded conductor or any bonding to it beyond the source. If everyone is using 240 volt appliances why don't they ground one line of the 240 volts and forget the center tap? That would make it like it is in most of Europe, then use switchgear like they use there as well instead of 120/240 North American gear that isn't designed for such a system.

The US previously sold thousands of surplus split phase 120/240v transformers to the power company in the Philippines. The reason the power company doesn't want to move the ground to one line of the 240v is because since almost all homes don't have ground bus bar. Most have zero experiences about bonding. If they will announce in papers that one must bond one of the 240v leg (grounded) to the neutral bus bar (nonexistence). People may misunderstood and touch the live one instead of the grounded leg (they don't know how to differentiate). This can result in mass casualties (hundreds of electrocution daily). Hence I don't think it can happen for a hundred years.

 

[kwired]

The US previously sold thousands of surplus split phase 120/240v transformers to the power company in the Philippines. The reason the power company doesn't want to move the ground to one line of the 240v is because since almost all homes don't have ground bus bar. Most have zero experiences about bonding. If they will announce in papers that one must bond one of the 240v leg (grounded) to the neutral bus bar (nonexistence). People may misunderstood and touch the live one instead of the grounded leg (they don't know how to differentiate). This can result in mass casualties (hundreds of electrocution daily). Hence I don't think it can happen for a hundred years.

If you wait for 100 years then make a change you will still have same misconceptions, just 100 years later. You have to educate people sometime and start making changes sometime or leave it in the mess it is now. You get away with things on insulated floors because the floor is insulated. We got away with the same thing a lot back when we didn't see equipment grounding on appliance cords. But when you have a grounded surface near such an appliance the risks go up.

 

[ptonsparky]

Why do you want to detect an Open Neutral? By the sounds of it, almost every residence is operating that way. You know it. Deal with it. Detecting the ON at the pole means nothing if you are not using one at the residence.

You are better off not allowing any 120v loads at all. Don't allow the sell of them. Having any in your possession is punishable by fine/imprisonment or death.

(any similarity to issues unrelated to electrical in the US is coincidental)

 

[kwired]

Why do you want to detect an Open Neutral? By the sounds of it, almost every residence is operating that way. You know it. Deal with it. Detecting the ON at the pole means nothing if you are not using one at the residence.

You are better off not allowing any 120v loads at all. Don't allow the sell of them. Having any in your possession is punishable by fine/imprisonment or death.

(any similarity to issues unrelated to electrical in the US is coincidental)

I don't know if you been following his other threads, but apparently where he is at it is common to have 120/240 supply, but only bring the ungrounded conductors to the service equipment:huh: But at same time, that means the neutral is always open so I don't really know what he wants to detect here, but a common thing in all threads seems to be finding a way of providing effective equipment grounding when you have no grounded conductor to bond to.

 

[winnie]

In addition to the home that he is trying to improve (in the context of poor installation standards) there is also a commercial building, where the neutral was in fact brought to the service.

The only '120V' load in this commercial building is a surge protective device which is connected l-l and l-n.

IMHO better than trying to detect the open neutral is to find a surge protective device which will tolerate an open neutral and still function.

-Jon

 

[ptonsparky]

I don't know if you been following his other threads, but apparently where he is at it is common to have 120/240 supply, but only bring the ungrounded conductors to the service equipment:huh: But at same time, that means the neutral is always open so I don't really know what he wants to detect here, but a common thing in all threads seems to be finding a way of providing effective equipment grounding when you have no grounded conductor to bond to.

Yes, I've been following. They are all in the realm of DIY.

The idea of 2 pole GFCIs could possible "work" by using a GE and earth return as the neutral connection for the GFCI at the home. NO other line to earth could be allowed. None. IDK how much current a GFCI requires to operate. How is it affected by line to earth voltage change? How many does the home need? How good is the homes GES? What are the neighbors doing at their home(s)?