Generac XG7000E and Interlock Kit

[jwelectric]

OK, all this you are talking about is about SDS and non-SDS. Where in all that does it say a neutral break transfer is required?
To the contrary, look at the Informational Note to 250.30. It says the exact opposite of what you are saying is the only "safe" way to do it.

Pete read that note carefully. Where does it state that a stand-alone generator can be connected this way?
An onsite generator could be a generator that is the emergency power for a hospital or a nuclear power plant. It would also include generators outlined in 250.35.

250.34 is clear on the wording that a portable generator that has receptacles that supply the equipment being used to supply premises wiring must be installed as a SDS. In past editions this wording was in the body of the text. Over the years portable generators have been made where they don’t have receptacles but instead have lugs that the conductors land on and these have a place where the neutral bond can be lifted easily.

[jwelectric]

Hey Everybody new here. I know this is not what you want to here but I'm a carpenter not an electrician but can do my own electrical work but also know my limitations. I have learned a lot from the electricians I have worked with in the past. I just got a Generac GP5500 to replace my Honda 1800 watt. I plan on doing the same thing that Ted M is doing at the start of this thread. I can handle this install and under stand what I'm doing. JW or anybody if you could please explain in simpler terms what this issue is with the grounding. Does it come down to the fact that HO's are not grounding the the generators at the provided grounding lug to earth? I have a sub panel in my detached garage where my gen will be run and I planned on running an 8ga. wire to the panel and attach it to the ground buss bar inside and when I need to use it I will attach the ground wire to the lug on the generator. I have read else where that this is acceptable or should the wire be connected to a copper grounding rod? And to Rich B what part of Jersey are you?

Those generators are not required to be connected to earth if used in the proper manner. The earth connection does nothing to clear a fault. What you want to do is ensure there is a path back to the source (generator) in the event of a ground fault.

If you don’t fully understand this then you are refuting your own statement , “I can handle this install and under stand what I'm doing.”

Here is the code section that governs the use of these stand-alone generators. Pay close attention to the note at the bottom

250.34 Portable and Vehicle-Mounted Generators.
(A) Portable Generators. The frame of a portable generator shall not be required to be connected to a grounding electrode as defined in 250.52 for a system supplied by the generator under the following conditions:
(1) The generator supplies only equipment mounted on the generator, cord-and-plug-connected equipment through receptacles mounted on the generator, or both, and
(2) The normally non–current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are connected to the generator frame.
(B) Vehicle-Mounted Generators. The frame of a vehicle shall not be required to be connected to a grounding electrode as defined in 250.52 for a system supplied by a generator located on this vehicle under the following conditions:
(1) The frame of the generator is bonded to the vehicle frame, and
(2) The generator supplies only equipment located on the vehicle or cord-and-plug-connected equipment through receptacles mounted on the vehicle, or both equipment located on the vehicle and cord-and-plug-connected equipment through receptacles mounted on the vehicle or on the generator, and
(3) The normally non–current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are connected to the generator frame.
(C) Grounded Conductor Bonding. A system conductor that is required to be grounded by 250.26 shall be connected to the generator frame where the generator is a component of a separately derived system.
Informational Note: For grounding portable generators supplying fixed wiring systems, see 250.30.

[Speedy Petey]

Pete read that note carefully. Where does it state that a stand-alone generator can be connected this way?
An onsite generator could be a generator that is the emergency power for a hospital or a nuclear power plant. It would also include generators outlined in 250.35.

250.34 is clear on the wording that a portable generator that has receptacles that supply the equipment being used to supply premises wiring must be installed as a SDS. In past editions this wording was in the body of the text. Over the years portable generators have been made where they don’t have receptacles but instead have lugs that the conductors land on and these have a place where the neutral bond can be lifted easily.

An on-site generator could also be a portable unit that is connected to the building electrical. 250.34 could apply just as much as 250.35.
If you read that note is SPECIFICALLY states that as long as the neutral is bonded it is NOT an SDS and does NOT need a neutral break transfer.
If you think a neutral break transfer is the only correct way to install a genny then WHY is this note there in the 2011 NEC?


A) I'm not sure where you see that 250.34 says this about an SDS. That section is on grounding and bonding.

[jwelectric]

Is it not through the grounding and bonding that makes a generator either a SDS or a non-SDS? This is why it is addressed in 250.

These small stand-alone self contained generators have over current protection (may be a reset button) that protects the branch circuit conductors that supply receptacles. (See branch circuit conductors in 100) In order for this over current device to function properly the neutral must be bonded to the equipment grounding conductor and the frame of the generator. This makes this small stand-alone generator a SDS.

To lift this neutral to EGC bond would defeat the ground fault path for the devices on the generator. There would no longer be a fault path for the other receptacles mounted on the frame of the generator.

These circuits on the generator are branch circuits until we connect them to a premises wiring system and they become feeders. Should this be done then in order to keep the fault path for the other devices located on the generator the generator must be installed as a SDS.
Look at my last post and see the sentence highlighted in red.

Using the NEC only we can understand a lot about UL Standards without having to buy the Standard.
Portable generators that have devices mounted to the frame have the earth grounding covered in 250.34. What about the GFCI protection of these devices, where are they covered in the NEC? 590.6(A)(3) of the 2011 edition.
What does this mean to me? This is telling me that a stand-alone generator is designed for use as temporary power which is a long way from being optional standby as outlined in 702 and the Note under 250.34

UL and the NEC have come forth with the requirement that all 15, 20, and 30 amp receptacles on portable generators must be GFCI protected on generators manufactured or remanufactured after January 1, 2011. In order to keep the GFCI from tripping the only way these can be connected to the premises wiring is by installing them as a SDS or voiding the listing by lifting the neutral bond from the frame of the generator which could cause someone to be hurt.

[DonL]

Using the NEC only we can understand a lot about UL Standards without having to buy the Standard.

If it is a Standard why would you need to buy it ?

UL Standard is not always the best or safest, it is a way to pay for and place stickers on many products, That may or may not meet NEC requirements.

[illinois524]

Is it not through the grounding and bonding that makes a generator either a SDS or a non-SDS? This is why it is addressed in 250.

UL and the NEC have come forth with the requirement that all 15, 20, and 30 amp receptacles on portable generators must be GFCI protected on generators manufactured or remanufactured after January 1, 2011. In order to keep the GFCI from tripping the only way these can be connected to the premises wiring is by installing them as a SDS or voiding the listing by lifting the neutral bond from the frame of the generator which could cause someone to be hurt.

Please bear with me as I'm trying to understand and learn here. OK SDS stands for? When you say GFCI protected I think of a outlet that you might see in a bathroom or kitchen. But when it comes to these gens they don't come with those kinds of outlets (or at least mine doesn't) so does that mean they are built into the circuit breakers that are next to the outlets (push button reset) or some how built into the electrical system?

[illinois524]

In saying that I meant that I can handle all of the physical wiring and install of parts but I'm trying to learn from people like you that do this for a living about NEC codes. Quite a few of my neighbors are looking to make hook ups but don't take the time to learn and read what is right and wrong with the way they will be hooking up their gens. So the more I can learn the more info I can pass on to others.

[DonL]

In saying that I meant that I can handle all of the physical wiring and install of parts but I'm trying to learn from people like you that do this for a living about NEC codes. Quite a few of my neighbors are looking to make hook ups but don't take the time to learn and read what is right and wrong with the way they will be hooking up their gens. So the more I can learn the more info I can pass on to others.

Really the Bottom line is that you should not feed a House with a Portable Generator.

Everything should be run on an Extension cord.

A REAL Generator made for that purpose will normally be installed properly by a Professional that knows. Where You live makes a BIG difference. Not all codes are the same.

During a real Emergency, You can do whatever it takes.

If You try to Understand the Codes you can just become lost in the BS and numbers.

Be careful and get a Pro, Because learning NEC or UL Rules will make the average person do it wrong most of the time.


It is not Rocket Science like all the codes make it out too be...

[jwelectric]

If it is a Standard why would you need to buy it ?

UL Standards are the guide line that manufacturers use when designing there product. A couple of examples would be UL Standard 1699 for arc fault devices, UL Standard 943 for ground fault circuit interrupters, UL Standard 2200 for generators and so on and so forth. UL Standard 943 states that a GFCI device must open between 4 and 6 milliamps. UL Standard 2200 states that generators that have devices mounted on the generator frame must have the Equipment Grounding Conductor as well as the neutral bonded to the frame.

These standards are for the manufacturer of the product and are not intended for the general public although you could have one for a price. The UL White Book is the guide for installing the devices and appliances that are listed by UL. The UL White Book can be accessed through the internet.

UL Standard is not always the best or safest, it is a way to pay for and place stickers on many products, That may or may not meet NEC requirements.

It is through the testing done by laboratories such as UL that keeps the items we buy safe and working like they are supposed to work. All of the National Recognized Testing Laboratories work hand in hand with the National Fire Protection Association and the Consumer Product Safety Commission to insure that the appliance and equipment we use daily are the safest they can be. This is an ongoing effort by all involved. It is not a rip off scheme to sell space to insert some type of label.

[jwelectric]

Please bear with me as I'm trying to understand and learn here. OK SDS stands for?

Separately Derived System. This means that the neutral and equipment grounding is bonded in or at the generator or transformer. When the neutral is not bonded at the generator or transformer then it is a Non-Separately Derived System

When you say GFCI protected I think of a outlet that you might see in a bathroom or kitchen. But when it comes to these gens they don't come with those kinds of outlets (or at least mine doesn't) so does that mean they are built into the circuit breakers that are next to the outlets (push button reset) or some how built into the electrical system?

It could be any of the above

[DonL]

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 ???

[jwelectric]

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]

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]

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?

[drick]

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.