Generac XG7000E and Interlock Kit

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DonL

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UL Standards are the guide line that manufacturers use when designing there product.


In this day and age ,the manufacturer builds products as Specified buy the Company that designed the product.

Most manufacturers do not design what they build.

Manufacturers build to meet the required Spec. that the Company they are building for Provides, Not NEC, UL or God.

A good example of UL rated Junk, Is a 16 Gauge 120V 20 Amp Extension Cord.

Most UL Testing, Just means that this sticker will say affixed to the product, Long enough to sell it.


Who are we trying to kid ???
 
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JWelectric

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In this day and age ,the manufacturer builds products as Specified buy the Company that designed the product.

Most manufacturers do not design what they build.

Manufacturers build to meet the required Spec. that the Company that are they building for Provide, Not NEC, UL or God.

A good example of Junk UL rated stuff, Is an 16 Gauge 20 Amp Extension Cord.

Most UL Testing, Just means that this sticker will say affixed to this product, Long enough to sell it.


How are you trying to kid ???

Sometimes people show their ignorance by speaking.

There is no such thing as a 16 gauge 20 amp extension cord and there has never been one

Now do you have anything constructive to add? If not be quite
 

DonL

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Sometimes people show their ignorance by speaking.

There is no such thing as a 16 gauge 20 amp extension cord and there has never been one

Now do you have anything constructive to add? If not be quite


When is the last time you bought an extension cord at WMart ?.

How many do you need, I can pick You up a few.
 

Northerner

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I’m a homeowner and am thoroughly confused after reading this and other articles about grounding a generator. (I'm not an electrician, but am a licensed ham radio operator, so I know a little more about electricity and electronics than most homeowners, but honestly, not that much).

I just bought a new 6700-watt (7300-watt surge) portable generator. Before I bought it, an electrician installed an interlock kit (UL listed) to enable me to legally connect the generator to my house wiring. In tests, including a 2-hour test during an outage a week after this was connected, the generator was able to power my well pump, two furnaces, two fridges plus some miscellaneous low power items (lights, APC SmartUPS protected computers) without getting overloaded. It ran at 114 to 116 volts, with a frequency of 61.8 hertz. Voltage varied only 2 to 3 volts when a furnace turned on or some other appliance surged. I can very easily turn breakers on and off to reduce strain on the generator if need be, and with our woodstove, can get by with one or even no furnaces on.

The generator neutral is bonded to the ground at the generator. It is connected via a 40-foot cord. The interlock kit does not shift the neutral. I asked the electrician if I should install a ground rod at the generator, and he said that the generator is using the house ground, so I shouldn’t need it. He also said that some inspectors require that you install a ground rod in such installations, and about half the articles that he reads about generators say that the generator should be grounded at its site, and the other half say that this is second ground is unnecessary.

I haven’t installed a ground rod at the generator.

I was speaking to the engineering manager at the manufacturer (manufacturer's name undisclosed, because he told me some things out of school) about another issue about the generator, and while doing so, he brought up the grounding issue (which started me on this wild goose chase across the internet). He said that he disagrees with UL about requiring bonded neutrals. He told me that it is best if I have an electrician convert the generator to a floating neutral if I am going to connect it to my house wiring.

At the same time, he said that there has never been a record of a fatality caused by having a bonded neutral generator hooked up (legally) to house wiring. He also said that the GFCI’s will no longer work if I was to use the generator in some other way if I changed it to a floating neutral.

I don’t plan on using the generator in any other place than where it is, which is inside a shed I custom-built for the generator (plenty of ventilation, and very dry, by the way). I don’t really have the need for the 120 volt outlets.

What should I do?

1) Leave the generator as is, without a ground rod, and continue to use the house ground point at the main breaker box as the generator ground?

2) Install a ground rod next to the generator and wire it to the generator?

3) Convert the generator so it has a floating neutral, and connect it to the house wiring without a ground rod at the generator?

My preference would be not to have the generator’s innards altered, as it may void the warranty. I can install a ground rod in half an hour, but I’ve also heard that this can do more harm than good.

I'm also more concerned with safety than with complying with code, if code outlines an unsafe situation. (Please don't suggest extension cords - I can't run 240 v appliances with them, and don't feel that having extension cords running thoughout my house is safe).

An IEEE article I read about generator grounding went through a series of real-life situations, and found significant variance in systems. Some had problems with current intermingling and “[some] installations, whether code-complying or non-code complying, may show little deleterious effect, because of favorable system impedances which tend to attenuate ‘stray’ currents.” Read the entire article for total confusion: http://mercedeelectric.com/Documents/00585847.pdf

By the way, JW Electric, I would be interested to know more about the refueling fire. Was he refueling a hot generator that had been running and had just run out of gas (could the fire have been caused by heat?), or was it a cold generator that was hooked into his panel through a transfer switch, and the cause of the fire was unclear, but pointed to an electrical issue? Could an undischarged capacitor in the generator have caused the fire? Was he refueling a generator while it was running?
 
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Drick

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I asked the electrician if I should install a ground rod at the generator, and he said that the generator is using the house ground, so I shouldn’t need it. He also said that some inspectors require that you install a ground rod in such installations, and about half the articles that he reads about generators say that the generator should be grounded at its site, and the other half say that this is second ground is unnecessary.

Do not drive a ground rod. What do you think ground rods do anyway? Everyone thinks they are magical devices that suck stray current into the ground. Power generated by the generator will always return to the generator either on the neutral wire or the ground wire. It will not go into the ground at the service entrence, around your house, and back up the ground rod you installed next to the generator. Ground rods are for lightning protection. The ground rods at your service entrance will do just fine.

He said that he disagrees with UL about requiring bonded neutrals. He told me that it is best if I have an electrician convert the generator to a floating neutral if I am going to connect it to my house wiring.

He disagrees about UL requiring bonded neutrals where? At the generator I assume. If you use the generator as a stand alone device connected to a drill, lamp, saw, or whatever AND the generator suffers an internal fault the frame will become energized. Without the bond there is no way to trip the circuit breaker on the generator. You will be very sorry when you touch the generator frame in this case.


At the same time, he said that there has never been a record of a fatality caused by having a bonded neutral generator hooked up (legally) to house wiring.
Thats because 99.99 percent of the time its not a problem. Mine is set up this way and I am not in the least bit concerned about it.

He also said that the GFCI’s will no longer work if I was to use the generator in some other way if I changed it to a floating neutral.
Thats probably not true, GFICs don't need a ground in order to operate properly. They measure the power going out on the hot wire and make sure its the same as the power coming pack on the neutral wire.

I don’t plan on using the generator in any other place than where it is, which is inside a shed I custom-built for the generator (plenty of ventilation, and very dry, by the way). I don’t really have the need for the 120 volt outlets.
This is not a good idea. Portable generator are designed to be operated outdoors. Where exactly did the electrician place the generator inlet box - on the house or in the shed?


What should I do?

1) Leave the generator as is, without a ground rod, and continue to use the house ground point at the main breaker box as the generator ground?

2) Install a ground rod next to the generator and wire it to the generator?

3) Convert the generator so it has a floating neutral, and connect it to the house wiring without a ground rod at the generator?

Personally I'd live with the double bonded neutral. The work has already been done by a professional and double bounded neutrals are as common as grass when it comes to generator hookups. If you decide to lift the neutral bond at the generator you should never operate the generator unless it is wired to the house. Your only bonding point protecting your generator frame is at your service entrance now so running it with the house cord disconnected leaves you vulnerable to electric shock thru the generator frame in the event of a component failure.
 

JWelectric

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The generator neutral is bonded to the ground at the generator.
As it should be

He also said that some inspectors require that you install a ground rod in such installations, and about half the articles that he reads about generators say that the generator should be grounded at its site, and the other half say that this is second ground is unnecessary.
This alone is enough to prove that there is a lot of misunderstanding when it comes to these stand-alone generators

I haven’t installed a ground rod at the generator.
And there is no need to as long as the generator is being used as outlined in 250.34(A)
Being that it is in another building (shed) then 250.32 and 225 Part II comes into play which would require the grounding electrode system to be installed at both places. To install the rod at the shed would cause no harm to anything

I was speaking to the engineering manager at the manufacturer about another issue about the generator, and while doing so, he brought up the grounding issue He said that he disagrees with UL about requiring bonded neutrals. He told me that it is best if I have an electrician convert the generator to a floating neutral if I am going to connect it to my house wiring.
You mean the person that wants to ensure the sale of their product?

At the same time, he said that there has never been a record of a fatality caused by having a bonded neutral generator hooked up (legally) to house wiring. He also said that the GFCI’s will no longer work if I was to use the generator in some other way if I changed it to a floating neutral.
He meant to say that none that he knew of. During Katrina there were at least two documented deaths involving these generators. He also meant to say that if the receptacle that is supplying the house is GFCI protected then the device will trip if it is bonded on both ends.

What should I do?
Based on what I have read I would recommend a larger generator
If this is out of the question then I would have someone install a transfer that also switched the neutral.
My preference would be not to have the generator’s innards altered, as it may void the warranty. I can install a ground rod in half an hour, but I’ve also heard that this can do more harm than good.
OI agree with you on not altering the wiring of the generator but suggest the change of transfer switches. Installing a rod at the generator will cause no harm at all


I'm also more concerned with safety than with complying with code, if code outlines an unsafe situation. (Please don't suggest extension cords - I can't run 240 v appliances with them, and don't feel that having extension cords running throughout my house is safe).
The NEC is a minimum safety standard. To do anything less than what it requires will be an unsafe installation plain and simple. I know that there are a lot of folks that think they are wiser than a document that has been around for more than a hundred years and is constantly being revised by some of the greatest electrical minds in the world but I think you are smart enough to figure that one out yourself.

An IEEE article
This is concerning a different animal than what you have and would have no reflection at all on your installation

By the way, JW Electric, I would be interested to know more about the refueling fire. Was he refueling a hot generator that had been running and had just run out of gas (could the fire have been caused by heat?), or was it a cold generator that was hooked into his panel through a transfer switch, and the cause of the fire was unclear, but pointed to an electrical issue? Could an undischarged capacitor in the generator have caused the fire? Was he refueling a generator while it was running?
Facts that are known;
It was a stand-alone generator
Connected to the home via a cord
Panel front transfer
Neutral bonded on both ends

What is assumed:
He made the comment that he felt a shock which would lead one to think he was refueling while the unit was running
The fire started due to the generator being in use.

Summary:
A generator was connected to the premises wiring via a panel interlock. The generator had a neutral bond as well as the neutral bond in the service equipment. This caused a parallel path on the neutral and equipment grounding conductor between the generator and the service equipment.
The victim stated that he felt a shock which caused involuntary movement causing a large spill of fuel causing the fire.
Based on the statement of victim, “I felt a shock” it is understood that the generator was running while being refueled.
 

DonL

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I’m a homeowner and am thoroughly confused after reading this and other articles about grounding a generator. (I'm not an electrician, but am a licensed ham radio operator, so I know a little more about electricity and electronics than most homeowners, but honestly, not that much).

If you are using any Radio Equipment or have any antennas in operation at your house then it would be a good idea to Install a ground rod next to the generator and wire it to the generator.

That would help to eliminate any RFI produced by the generator, Noise normally heard on HF Frequencies.

It would also provide better lightening protection for your house, Just in case one of your Radio Antennas get struck by lightening.

Your antennas should be grounded properly also.


That may not be in the NEC® code, But rather something that the ARRL® would recommend.
 
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Northerner

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If you are using any Radio Equipment or have any antennas in operation at your house then it would be a good idea to Install a ground rod next to the generator and wire it to the generator.

That would help to eliminate any RFI produced by the generator, Noise normally heard on HF Frequencies.

It would also provide better lightening protection for your house, Just in case one of your Radio Antennas get struck by lightening.

Your antennas should be grounded properly also.


That may not be in the NEC® code, But rather something that the ARRL® would recommend.

DonL: I wouldn’t operate my ham radio equipment during a power outage, unless it was for emergency communications. If so, I would use a marine battery as a power source. My antennas are not above house level, and have lightning arrestors and a ground rod.
 

DonL

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DonL: I wouldn’t operate my ham radio equipment during a power outage, unless it was for emergency communications. If so, I would use a marine battery as a power source. My antennas are not above house level, and have lightning arrestors and a ground rod.

Around here we fire the Radio Equipment up to provide emergency communications for others that need it.

I hope that your Battery is grounded, lol
 

Northerner

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Thanks, Drick and jwelectric. Unfortunately, I now have three different opinions, one from the manufacturer's engineering manager who has a BS in electrical engineering, 15 years' experience in the design/manufacture of portable generators and wasn't trying to sell me a generator (I called him to find out about the unit's distortion post-sale, and he brought up the floating neutral vs. bonded neutral issue without my asking) and the opinion of what I would assume are two electricians who also seem to be knowledgeable.

By the way, to clarify a couple things:

The shed is an oversized doghouse or outhouse with lots of clearance, and not a separate building that any person can fit into. I was told to run the generator with the door open if the weather was bad, and to bring it outside of the shed if the weather was good. There are two louvers inside the shed. It is essentially a three-sided, ventilated enclosure when the door is open. But this is not what my question was about – I have people locally who have seen the generator shelter feel comfortable with it.

The manufacturer’s Engineering Manager didn’t say that he doesn’t believe in bonded neutrals. He said that he believes that a generator needs a floating neutral only when connected to house wiring. He also said that this could cause problems if the generator with a floating neutral is then used if it is not connected to the house wiring, because then it would no longer have ground protection.
 
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Northerner

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Alas, I wouldn't ground my marine battery, which probably would put me at al kinds of risk :) (especially when you consider that my 100-watt transmitter has an earth ground).

My best ham radio rig for emergency communications is in my car, and yes that is well-grounded to the chassis. But if that was unnecessary during Hurricane Irene, when even our roads were gone, I doubt if it will be necessary in the future.
 
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JWelectric

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Thanks, Drick and jwelectric. Unfortunately, I now have three different opinions, one from the manufacturer's engineering manager who has a BS in electrical engineering, 15 years' experience in the design/manufacture of portable generators and wasn't trying to sell me a generator (I called him to find out about the unit's distortion post-sale, and he brought up the floating neutral vs. bonded neutral issue without my asking) and the opinion of what I would assume are two electricians who also seem to be knowledgeable.

By the way, to clarify a couple things:

The shed is an oversized doghouse or outhouse with lots of clearance, and not a separate building that any person can fit into. I was told to run the generator with the door open if the weather was bad, and to bring it outside of the shed if the weather was good. There are two louvers inside the shed. It is essentially a three-sided, ventilated enclosure when the door is open. But this is not what my question was about – I have people locally who have seen the generator shelter feel comfortable with it.

The manufacturer’s Engineering Manager didn’t say that he doesn’t believe in bonded neutrals. He said that he believes that a generator needs a floating neutral only when connected to house wiring. He also said that this could cause problems if the generator with a floating neutral is then used if it is not connected to the house wiring, because then it would no longer have ground protection.

What he is telling is all true but we also have the NEC and its requirements to contend with. We have the installation instructions outlined by the UL White Book which must be adhered to for the installation to be proper and correct and safe.

The one thing that I as well as others will quickly tell you is to not float the neutral at the generator as several thing could go wrong and you will be left holding the bag.
 

JWelectric

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The shed is an oversized doghouse or outhouse with lots of clearance, and not a separate building that any person can fit into.

Doesn't matter the size.

250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).

(A) Grounding Electrode. Building(s) or structure(s) supplied by feeder(s) or branch circuit(s) shall have a grounding electrode or grounding electrode system installed in accordance with Part III of Article 250

225 II. Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s)


The only thing that matters is that it is a Structure

I will add that I wouldn't install an electrode unless I was planning on an inspection
 

DonL

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The term Structures in NEC rules need to be better defined.


Nonbuilding structures, also referred to simply as structures, are those not designed for continuous human occupancy. The term is used by architects and structural engineers to distinctly identify structures that are not buildings.


Examples of nonbuilding structures:

Steam Generators
Aerial lift pylon
Boat lifts
Bridges and bridge-like structures (aqueducts, overpasses, trestles, viaducts, etc.)
Building canopies
Chimneys and smokestacks
Dams
Water towers
Electric power transmission towers
Ferris wheels and observation wheels
Furniture
Monuments
Parking structures
Offshore oil platforms (except for the production and housing facilities)
Packaging
Pallet rack
Piers
Roller coasters
Retaining walls
Sewers
Ships and boats
Sports equipment
Cranes
Automobiles
Machinery
Structures designed to support, contain or convey liquid or gaseous matter, including
Cooling towers
Pipelines
Distillation equipment and structural supports at chemical and petrochemical plants and oil refineries
Storage tanks
Television and radio masts and towers
Tunnels
Wharves


I believe that may include dog houses, Unless the Dog can talk.
 
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JWelectric

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Per the NEC

Structure. That which is built or constructed.

A 4x4 post in the ground to hold something electrical is a structure
 

DonL

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Per the NEC

Structure. That which is built or constructed.

A 4x4 post in the ground to hold something electrical is a structure


OK then everything on earth is a built structure.

We can not connect anything electrical to anything electrical.

Makes more sense now...
 

JWelectric

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It simply means that should you decide to wire something from one structure to another with anything other than a single circuit a grounding electrode system must be installed as well as a means to disconnect the structure from the source of power.
 
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