Another Generator Grounding Question

[jwelectric]

Now if there is no bond between neutral and ground anywhere, a short at the high end of one winding could indeed raise the neutral to ground voltage to 120 volts and the opposite phase terminal to a240V above ground.

On a generator with the so called floating neutral this is exactly what happens. The bond at the service equipment is down stream of the source which is not bonded therefore no fault clearing path.
Remember the electrode does not clear faults

 

[ceb58]

Really? Show me a resi grade manual or auto transfer switch with a switched neutral.

OK, no problem
http://www.auroragenerators.com/generator-transfer-switches/panel-link-x-series

 

[GoldDigger]

jwelectric: There is where I differ with you. As long as there is a bond somewhere it does not matter whether it is "downstream" or at the generator.
The fault will not be cleared if the cord to the bonding point is unplugged, but there will not be any loads to be damaged either.
If the transfer switch interrupts the neutral, there will be no bond affecting the generator, which is exactly why there must be a bond at the generator in such cases.
Sent from my XT1080 using Tapatalk

 

[iceworm]

Mike- I asked nice that you keep the issues separated. Sigh - you refused.

Portable generators that have receptacles are required to have the neutral bonded to the frame of the generator by 250.26 as referenced in 250.34.. ....

Better read 250.34 again. Doesn't even say that at all. (A) says the gen is not required to be connected to a grounding electrode. (B) doesn't apply. (C) does not apply in this case, the gen is to be connected non-SDS.

.Note in 250.34 although not enforceable the code section pointed out within is very enforceable,

Not only does 250.34.C not apply, neither does the informational referencing 240.30. The gen is not being connected SDS.

No FTCN does not point out the code sections but it does reference the code itself which we as installers are to conform with. ....

This gets you another "Huh?" the gen in question is 17kW. FTCN does not apply.

...Should a lead or even the winding itself short to the frame of the generator the voltage would find the neutral through the main bonding jumper of the service equipment which is the same place that the generator is connected to earth via the supply side bonding jumper or equipment bonding jumper if the generator has overcurrent devices. ...

Hummm ... I really wish you would separate these out - but you didn't. I think this one is about a generator winding fault delivering 240 volts to a 120V appliance. I still wish you would draw me a picture - at least you tied it down a bit better. So now my translation is; The gen has the NG bond removed and is connected 4W to the premises wiring system. The NG bond is supplied by the normal service panel bond. So No, not true.

Gen winding shorts to frame. Gen neutral is connected to premises neutral. Gen frame is connected to premises grounding lug in panel. Fault trips gen OCP. There is no physics that delivers 240 volts to the 120V circuit on a gen winding fault. You have not provided any explanation. I'm done with this one.

... Article 225 requires that the feeders coming from the generator to land in a disconnect either outside the building or nearest the point of entrance of the feeders and that this disconnect be suitable for use as service equipment .

Are you looking a 225.31, 32. 36? Okay, I see you could make a service rated disconnect stick - but only you. It's a stretch when the only premises wiring is a interlocked feeder from a panel to an outside located power inlet. The portable gen spends it's life unplugged and in my case stored inside, so I can get it started at -40F. When it is plugged in and running the disconnect is the cord at the power inlet and the gen CB and you could say, "Those are not service rated. They may well be safe, reliable, functional, but they don't say service rated." I give this one. in your area yo could make this stick. Okay I'll put a 2 pole non-fused disconnect above the inlet. I'll put this in the useless, but required in your area column.

I respectfully request you supply specific references instead of just flinging a code book at me. If you are going to cite a code reference please give the whole article.

... As to the listing of all the equipment that the manufactures advertised being used incorrectly I suppose the listed equipment in the attached picture would be allowed in a hazardous location, it is UL listed is it not? Maybe the instructions included in the listing is where we could find our answers if we would only take the time to stop reading advertisements and do the proper research. It will be in the UL listing that I will find that the pictured box below is not listed for a Class 1 Division 1 Zone 0 location. ...

This is smoke. Respectfully request you stay on topic.

... A careful read of the Proposal and the corresponding Comment which was made by the Technical Correlating Committee one can see that the requirements of Part II Article 225 does apply to the installation of an optional standby system. ....

More smoke. When the code panels start putting proposal and comment in the code I'll start reading it.

... Three wire cooking and dryers are no longer allowed as well as remote three wire buildings. There is a reason for this and I would be willing to bet that the danger involved is the reason why. It is like Knob and Tube wiring. It is allowed to remain in place but we are not allowed to install that type of installation nor are we allowed to install two wire NM cable but not required to remove it either.

And more smoke. If you wish to have a discussion about multiple NG bonds on the load side of the service - I respectfully suggest you reply to the post that discusses that issue.

... No more than as an inspector can I use manufacture flyers to enforce code compliance can the electrical contractor use it to defend code compliance. As an inspector I will be looking for compliance with the NEC as adopted into the statutes of my state. This will include everything found in the NEC concerning the installation from the generator to the end use. ...

Okay that sound goods - if it is true. A lot of your discussion has been of the flavor that "I don't like it and I won't tolerate it in my area." - Right at threatening if one does not agree.

I'm curious;
What is your response if you show up for the final and there is an interlock connected to an outside power inlet with your required service rated disconnect - but, no generator on-site, or in sight?
(Inspector) What's this for?
(Journeyman - or in my case of DIY to the max - me) Eventually they will get a generator - can't afford one right now. That is for the future connection.
(I) You have to have a 3W transfer switch and install it as an SDS.
(J) Owner tells me he is going to get a code compliant gen and install as a non-SDS.

What are you going to do? Tell the owner he is lying and to rip out the circuit?

With utmost respect, your not liking it does not make it unsafe or illegal.

ice

 

[qcroanoke]

Just dodged a bullet! Power went out here. (POCO xfmr explosion)
hooked up my non UL listed genset and turned it on transferred the power via 200 amp MTS. All is well. As Johnny Winter put it "still alive and well"
Mother in law lives behind me. She also has a non UL listed genset and a non UL listed interlock kit which worked perfectly.
I should add it was raining, however both units were out of the weather.
beat the odds again.......

 

[ActionDave]

Just dodged a bullet! Power went out here. (POCO xfmr explosion)
hooked up my non UL listed genset and turned it on transferred the power via 200 amp MTS. All is well. As Johnny Winter put it "still alive and well"
Mother in law lives behind me. She also has a non UL listed genset and a non UL listed interlock kit which worked perfectly.
I should add it was raining, however both units were out of the weather.
beat the odds again.......

Great Scott man! Have you no regard for your future? Do what you must, but please do what you can to stay safe. I hope you are on a wood floor and are accessing the internet with a wireless connection.

You may have well used one or two of your nine lives. I don't think I'd risk another one when utility power comes back. Best to wait for the genset to run out of gas before you transfer back. Even then I would hope you'd be wearing clothes with all natural fibres and absolutely no metal on them anywhere.

 

[jwelectric]

Iceworm

250.26 Conductor to Be Grounded ? Alternating-Current Systems.
For ac premises wiring systems, the conductor to be grounded shall be as specified in the following:
(1) Single-phase, 2-wire ? one conductor
(2) Single-phase, 3-wire ? the neutral conductor

Where is the exception for portable generators?

225.32 Location.
The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors.

Again no exception for portable generators and we can even find more information concerning this here

702.12 Outdoor Generator Sets.
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.

And this is what 225.36 has to say

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.

You and golddigger are both mistaken about the bonding in the service panel clearing a fault with the generator unless the generator is bonded to the neutral for the other devices located on the generator.

In 250.34 there are three different types of generators being talked about.

1. Portable with receptacle mounted on the frame
2. Vehicle mounted generators with receptacle mounted on the frame
3. Generators that don?t have receptacles mounted on the frame

The informational note applies to the entire section not just (C) as there would be no need for it to address C now would there.
Once the generator is connected to the premises wiring then it must comply with 250.30 which addresses which type of system?

I'm curious;
What is your response if you show up for the final and there is an interlock connected to an outside power inlet with your required service rated disconnect - but, no generator on-site, or in sight?
(Inspector) What's this for?
(Journeyman - or in my case of DIY to the max - me) Eventually they will get a generator - can't afford one right now. That is for the future connection.
(I) You have to have a 3W transfer switch and install it as an SDS.
(J) Owner tells me he is going to get a code compliant gen and install as a non-SDS.

What are you going to do? Tell the owner he is lying and to rip out the circuit?

With utmost respect, your not liking it does not make it unsafe or illegal.

I will point out the code sections outlined above and reject the installation as any other code official would do if they are doing the job they have sworn to do.

 

[AllCircuitsElectrical]

Simple fix ..

"Pre-wired for fast, easy connection to the transfer switch and load center to isolate the utility and generator neutrals up to 30 Amp. For neutral bonded generators."

Model # 6297

http://www.generac.com/Portables/Manual_Transfer_Switches/Products/Optional_Accessories/

 

[qcroanoke]

Great Scott man! Have you no regard for your future? Do what you must, but please do what you can to stay safe. I hope you are on a wood floor and are accessing the internet with a wireless connection.

You may have well used one or two of your nine lives. I don't think I'd risk another one when utility power comes back. Best to wait for the genset to run out of gas before you transfer back. Even then I would hope you'd be wearing clothes with all natural fibres and absolutely no metal on them anywhere.

 

[iceworm]

Iceworm

250.26 Conductor to Be Grounded ? Alternating-Current Systems.
For ac premises wiring systems, the conductor to be grounded shall be as specified in the following:
(1) Single-phase, 2-wire ? one conductor
(2) Single-phase, 3-wire ? the neutral conductor

Where is the exception for portable generators? ....

Doesn't need one - treated as any other non-sds
(late note: See below. I understand why you think this.)

225.32 Location.
The disconnecting means shall be installed either inside or outside of the building or structure served or where the conductors pass through the building or structure. The disconnecting means shall be at a readily accessible location nearest the point of entrance of the conductors.

Again no exception for portable generators and we can even find more information concerning this here

702.12 Outdoor Generator Sets.
Where an outdoor housed generator set is equipped with a readily accessible disconnecting means located within sight of the building or structure supplied, an additional disconnecting means shall not be required where ungrounded conductors serve or pass through the building or structure. The disconnecting means shall meet the requirements of 225.36.

And this is what 225.36 has to say

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.

702 does not apply. Suggest you read 702 Scope. The rest is fine. Already discussed. You have no new information - done

...You and golddigger are both mistaken about the bonding in the service panel clearing a fault with the generator unless the generator is bonded to the neutral for the other devices located on the generator. .

As I said in the last post, I'm done with this one. You refuse to draw it out. Your repitition does not make this any truer. You have a physics problem here not a code problem. You are going to have to draw this one out your self.

In 250.34 there are three different types of generators being talked about.

1. Portable with receptacle mounted on the frame
2. Vehicle mounted generators with receptacle mounted on the frame
3. Generators that don?t have receptacles mounted on the frame

The informational note applies to the entire section not just (C) as there would be no need for it to address C now would there.
Once the generator is connected to the premises wiring then it must comply with 250.30 which addresses which type of system?.

I think I finally understand your position.

If a generator is portable (has wheels or can be carried by hand) it can not be connected to premises wiring as a non-SDS

Well, that certainly is an interesting position. There is no physics to show this as being unsafe. You are taking an informational note as a mandate to install portable generators as an SDS.

I'm curious:
What is your response if you show up for the final and there is an interlock connected to an outside power inlet with your required service rated disconnect - but, no generator on-site, or in sight?
(Inspector) What's this for?
(Journeyman - or in my case of DIY to the max - me) Eventually they will get a generator - can't afford one right now. That is for the future connection.
(I) You have to have a 3W transfer switch and install it as an SDS.
(J) Owner tells me he is going to get a code compliant gen and install as a non-SDS.

What are you going to do? Tell the owner he is lying and to rip out the circuit?

I will point out the code sections outlined above and reject the installation as any other code official would do if they are doing the job they have sworn to do.

That first part is okay - wrong but okay. But the second is really a stretch

You are stuck on Portable generator can only be connected as an SDS. I contend there are safe, code compliant methods to connect a temporary, portable generator to premises wiring as a non-SDS. Of course, since my work is industrial, both service fed with back-up generation and self generated with provision for temporary power connection, connecting portable (wheel mounted) generation as non-SDS is considered normal - even desireable. Generally causes a lot less grief. I'm pretty sure the electrons work exactly the same as they do in a residential application.

Repitition of your position is not reasoning nor proof. Unless you have something new, I'm done.

Although I do have a curiousity question - hasn't got anything to do with this discussion:
Do you consider a skid mounted generator, off-loaded by forklift, as "portable generation"? - just curious.

 

[iceworm]

Just dodged a bullet! Power went out here. (POCO xfmr explosion)
hooked up my non UL listed genset and turned it on transferred the power via 200 amp MTS. All is well. As Johnny Winter put it "still alive and well"
Mother in law lives behind me. She also has a non UL listed genset and a non UL listed interlock kit which worked perfectly.
I should add it was raining, however both units were out of the weather.
beat the odds again.......

Right on. Got to love it when things work per plan. Sometimes it takes me a few tries to get it figured out.

Couple of years ago I'm at my dad's place with a tarp and a weed burner warming up his gen - it's about -30F and the power has been out for 4 hours. I got it running before the place froze up - but it was a cold miserable fight.

So now, I've got an 800w, inverter, 4cyc gen. I don't think it weighs 20 lbs. I leave it in the garage.

The boiler is now powered through a flexible cord pluged into a recetpacle.

Yes, I'm certain there are several dozen code violations and I'm treading on rotted ice every second it is in use. And, I don't know what I'm whinning about. For a small matter of cubic money I could have a heated generator house. But I don't yet.

Power goes out, I unplug the boiler, connect to an extension cord run outside to the little gen. It runs the burner and circ pump. Thermostats/valves are not powered, I have to open the valves manually. It has enough fuel to last all night. The rest is candles, flashlights, electric lanterns. I tested it and it works, but I haven't had to do it for real yet.

I went through it with my wife - wrote and posted instructions in the boiler room. She is comfortable doing it when I am out of town. And she like it better than our previous plan - which was to drive 20 miles into town, get a motel, and call the insurance company.

I like your setup better.

ice

 

[david]

Hummm ... I really wish you would separate these out - but you didn't. I think this one is about a generator winding fault delivering 240 volts to a 120V appliance. I still wish you would draw me a picture - at least you tied it down a bit better. So now my translation is; The gen has the NG bond removed and is connected 4W to the premises wiring system. The NG bond is supplied by the normal service panel bond. So No, not true.

Gen winding shorts to frame. Gen neutral is connected to premises neutral. Gen frame is connected to premises grounding lug in panel. Fault trips gen OCP. There is no physics that delivers 240 volts to the 120V circuit on a gen winding fault. You have not provided any explanation. I'm done with this one.[/COLOR

ice

if I one of the 50 amp mobile homes here are unplugged and plugged into this generator would there still be a physics problem, or the same with the 240V supply cords to the many RV on mobile home sites. The premise system these are used on do not have to be connected with a (standard) feeder,they are slowly going away we still have 50 amp cord connected homes here.

 

[qcroanoke]

Right on. Got to love it when things work per plan. Sometimes it takes me a few tries to get it figured out.


I like your setup better.

ice

Thanks!
My generators are 7000 watt troybilts. I have 4 wire 30 amp inlets on both homes (twistlock) with 10/4 cords.
200 amp Manual transfer switch in my home.(only because I didn't know square D made an interlock for their HOM panel.) MIL's is an interlock I bought online.
Both gensets can be placed out of any rain or snow while running.
Like you I have went over it with my wife on what to do and the sequence to do it in.
I even have an emergency light at my panels so I don't have to fumble around with a flashlight.
Works for us.

 

[david]

if I one of the 50 amp mobile homes here are unplugged and plugged into this generator would there still be a physics problem, or the same with the 240V supply cords to the many RV on mobile home sites. The premise system these are used on do not have to be connected with a (standard) feeder,they are slowly going away we still have 50 amp cord connected homes here.

I guess I was expecting someone to come back and say you shouldn?t unplug the 50 amp mobile home cord , connect the generator to the service disconnect and ensure that the neutral bond at the premise stays intact.

Or someone to say there is a different standard used to connect RV to generators and if you use the 50 amp plug to connect to the generator it would be similar to connecting an RV so we might follow those rules.

So my question is if you say that there are different standards to connect to different structures are you not advocating following a standard.
So when is it ok to deviate from a standard or do I pick and choose what standard I follow or to what extent I deviate and go on my own?

 

[iceworm]

I guess I was expecting someone to come back and say you shouldn?t unplug the 50 amp mobile home cord , connect the generator to the service disconnect and ensure that the neutral bond at the premise stays intact.

Or someone to say there is a different standard used to connect RV to generators and if you use the 50 amp plug to connect to the generator it would be similar to connecting an RV so we might follow those rules.

So my question is if you say that there are different standards to connect to different structures are you not advocating following a standard.
So when is it ok to deviate from a standard or do I pick and choose what standard I follow or to what extent I deviate and go on my own?

David -
I didn't answer because I'm not familiar with Mobile homes or RVs or the differences between the two, nor any specifics about how the external panels are bonded, if the cord and plug is 3W or 4W, or how or if the internal panels are bonded. And I really try to not mouth off when I don't know.

As for your questions;
I advocate compliance, but not slavish compliance. I look for regulatory compliant methods to get the work done right - as opposed to looking for regulatory interpretations to block the work.

As for deviation: At my house I can pretty well do what I want - there's no controlling authority. I'm also aware the laws of God and Physics don't change just because there is no one looking over my shoulder.

For my work (on or for customer's premises) - never.

ice

 

[iceworm]

Thanks!
My generators are 7000 watt troybilts. I have 4 wire 30 amp inlets on both homes (twistlock) with 10/4 cords.
200 amp Manual transfer switch in my home.(only because I didn't know square D made an interlock for their HOM panel.) MIL's is an interlock I bought online.
Both gensets can be placed out of any rain or snow while running.
Like you I have went over it with my wife on what to do and the sequence to do it in.
I even have an emergency light at my panels so I don't have to fumble around with a flashlight.
Works for us.

nice

 

[jwelectric]

Ice

I love your perseverance but alas you are mistaken about Article 702 applying to any generator connected to a premises wiring system of a single family dwelling.
702.1 Scope.
The provisions of this article apply to the installation and operation of optional standby systems.
The systems covered by this article consist of those that are permanently installed in their entirety, including prime movers, and those that are arranged for a connection to a premises wiring system from a portable alternate power supply.

702.11 Portable Generator Grounding.
(A) Separately Derived System. Where a portable optional standby source is used as a separately derived system, it shall be grounded to a grounding electrode in accordance with 250.30.
(B) Nonseparately Derived System. Where a portable optional standby source is used as a nonseparately derived system, the equipment grounding conductor shall be bonded to the system grounding electrode.


There are many different types of portable and vehicle mounted generators and this discussion is about only one type, the type that is outlined in 250.34(A) that has receptacles for the purpose of taking power from the generator.

Even if a generator is being installed as a non-SDS believe it or not it has the neutral point of the generator connected to earth through the premises wiring system. This is required by 250.26 which does not have an exception for portable generators.

The title of 250.34 is; Portable and Vehicle-Mounted Generators.
A and B covers these two type of generators that have devices mounted to the frame and relieves the requirement of connecting them to a grounding electrode. C tells us that on these two type of generators that the midpoint of the winding is to be connected to the frame if the frame has devices mounted there upon. Remember that A and B relieves the requirement to connect the 250.26 conductor to earth.
There is nothing found in 250.34 that allows the removal of this bond if the generators have devices mounted there upon.

There are many different types of portable and vehicle mounted generators on the market today that do not have devices mounted on the frame and are required to have the cord terminated under lugs at the generator.

Any generator connected to a premises wiring system that is not for life safety or legally required will fall under the requirements of Article 702. Any generator that is located outside and the feeders serve the building will have to meet the requirements of Part II of Article 225. There are no exceptions except in the minds of those who persist in proving that it can be done and justifying it by the use of the word ?safer?

If safer is the key to making the installation of a stand-alone generator then by all means buy a couple of 100 foot #12 cords and do it the way it is meant to be done.

All of this is a moot point any way due to the requirement that all generators that have receptacles mounted on the frame the receptacle is to be GFCI protected and this will prevent the use of the generator as a non-SDS see 590.6(A)(3)


As to drawing you a picture, it didn?t happen yesterday, it didn?t happen today and I will be willing to bet you my last dollar that it ain?t gonna to happen tomorrow either. If you can?t understand that a non-bonded generator can have 240 volts at a 120 volt receptacle mounted on the frame a picture just ain?t gonna get the job done. Stop and take a deep breath and use that gray matter that keeps your eyes from falling back into your head and you will figure it out.

 

[GoldDigger]

A non-bonded generator can have 240 volts to ground on the receptacle, I will not deny that. But you cannot get 240 volts between the hot and neutral terminals of a 120 volt receptacle.


Sent from my XT1080 using Tapatalk

 

[iceworm]

I love your perseverance but alas you are mistaken about Article 702 applying to any generator connected to a premises wiring system of a single family dwelling. ...

I re-read 702 Scope. You are correct. 702 does apply to portable generators.

702.11 Portable Generator Grounding
(A) Separately Derived System. Where a portable optional standby source is used as a separately derived system, it shall be grounded to a grounding electrode in accordance with 250.30.
(B) Nonseparately Derived System. Where a portable optional standby source is used as a nonseparately derived system, the equipment grounding conductor shall be bonded to the system grounding electrode. ...

Okay. This is not news. For non-SDS this happens in the premises panel. We have been trying to tell you this for several days.

... Even if a generator is being installed as a non-SDS believe it or not it has the neutral point of the generator connected to earth through the premises wiring system. This is required by 250.26 which does not have an exception for portable generators.

Hummm ... I'm not working on "belief", I say it is knowledge. This is not an issue of faith. It is an issue of physics. I am aware of this. Been telling you this for a few days. You have been insisting the connection has to happen in the gen.

... The title of 250.34 is; Portable and Vehicle-Mounted Generators.
A and B covers these two type of generators that have devices mounted to the frame and relieves the requirement of connecting them to a grounding electrode. C tells us that on these two type of generators that the midpoint of the winding is to be connected to the frame if the frame has devices mounted there upon. Remember that A and B relieves the requirement to connect the 250.26 conductor to earth.
There is nothing found in 250.34 that allows the removal of this bond if the generators have devices mounted there upon.

There are many different types of portable and vehicle mounted generators on the market today that do not have devices mounted on the frame and are required to have the cord terminated under lugs at the generator.

Any generator connected to a premises wiring system that is not for life safety or legally required will fall under the requirements of Article 702. Any generator that is located outside and the feeders serve the building will have to meet the requirements of Part II of Article 225. There are no exceptions except in the minds of those who persist in proving that it can be done and justifying it by the use of the word ?safer?

If safer is the key to making the installation of a stand-alone generator then by all means buy a couple of 100 foot #12 cords and do it the way it is meant to be done.

All of this is a moot point any way due to the requirement that all generators that have receptacles mounted on the frame the receptacle is to be GFCI protected and this will prevent the use of the generator as a non-SDS see 590.6(A)(3) ....

This is smoke on so many levels. For example:

590.6 Ground-Fault Protection for Personnel. Groundfault
protection for personnel for all temporary wiring installations
shall be provided to comply with 590.6(A) and
(B). This section shall apply only to temporary wiring installations
used to supply temporary power to equipment
used by personnel during construction, remodeling, maintenance,
repair, or demolition of buildings, structures,
equipment, or similar activities. This section shall apply to
power derived from an electric utility company or from an
on-site-generated power source.​

And you want to apply this to a generator connection to a residence during a utility power outage?

Additionally, everybody understands the UL restricts listed 15kw and below. Everybody understands that North Carolina requires all residential electric must be listed. I don't recall exactly how you phrased it, but it was clear that a listed gen was required in NC. That was clear from about the first day. Suggest you go back and find the posts where the discussion shifted over to a 17kw. It would be easier for me if you could stay on point.

... As to drawing you a picture, it didn?t happen yesterday, it didn?t happen today and I will be willing to bet you my last dollar that it ain?t gonna to happen tomorrow either. If you can?t understand that a non-bonded generator can have 240 volts at a 120 volt receptacle mounted on the frame a picture just ain?t gonna get the job done. .

Didn't think you would. The picture is not for me. As I said, until you come up with other arguments or reasoning besides, "The Worm doesn't understand basic physics and electricity", I'm out of this discussion.

... Stop and take a deep breath and use that gray matter that keeps your eyes from falling back into your head and you will figure it out.

Ughh ... Hang on a minute and let me get the knife out of my back. Yeeeowwww .. Okay done.

Uh ... Mike, perhaps you should "Stop ...


"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"

This is not an original with me. But I don't know where I got it from. But still, it is a technical discussion based on knowledge - or should be.

I suspect that if you applied your tallent and knowledge to figuring out how to connect a gen as a non-SDS, you could in a minute - okay, maybe it would take you five.

ice

 

[iceworm]

Mike -
You never answered my curiousity question:
Do you consider a skid mounted generator, off-loaded by forklift, as "portable generation"? - just curious.

The reason I'm asking is most temporary installations I deal with are say, 30kw, 480V 5W, up to 800Kw, 480V, 5W, with a few 70kW, 208V 5W. Unless it is a stand alone installation with construction bangboards, the bond will be in the premises panel. I get the feeling you think this is a terrible thing - that a gen winding fault will put 208V on a 120V receptacle.

Ahh.. another curiousity Q: Will this same thing happen if a transformer is the non-SDS source? The scenerio is a double ended substation, connected M-T-M. Pretty common in industry. All I have seen have the NG bond in the switchgear. Transformers are 5W from the xfm secondaries to the switchgear mains. Neutrals are connected together in the switchgear, NG bond is in the switchgear. So, consider running with one main open, and the tie closed. If a similar winding fault occurs in the on-line xfm as you are seeing possible in a generator, does this put 480V between the phase and neutral?

ice