Generac XG7000E and Interlock Kit

Discussion in 'Electrical Forum discussion & Blog' started by Ted M, Dec 3, 2011.

  1. Ted M

    Ted M New Member

    Messages:
    12
    Location:
    Northern New Hampshire
    There is much confusion regarding connecting a portable generator to a service panel. I’d like some expert advice on doing this safely and legally.

    I ordered a Generac XG7000E from Home Depot. It will not be here until January 18.
    I tried to get an owner’s manual from Generac, but that requires knowing the exact serial number, which I do not have yet.

    My service panel is a 200 amp, 40-circuit Square D, QO type.

    I have a K-5210 Generator Interlock Kit to use. (www.interlockkit.com)

    The Generac XG7000E will run outside in the yard, connected with a standard 120/240V, 30 amp four-wire flexible cable with twist lock connectors to a Reliance PB30 power inlet box.

    From the box, attached to the outside of the house, will run 10/3 +G to a back-fed 30 amp CB.


    I’ve read the NEC sections about generators being an SDS now.
    I also read Mike Holt’s book on Grounding vs. Bonding.

    Some on this forum say that an SDS means the neutral is switched.
    Others say it’s an SDS if the neutral and ground is bonded.

    Which is it?

    And, specifically, does anyone know if the Generac XG7000E has a bonded Neutral-Ground?

    If bonded, can it be disconnected, so only one neutral path exists?

    If it IS bonded, then there will be two paths for neutral current.

    How does this comply with code?

    Is it impossible to use a Generator Interlock Kit now?

    Or must we now use a Reliance type “X†transfer switch, which switches neutrals also.

    I guess thousands of people buy generators and hook them up without going through all the confusion I’m having, but I want to get it right.

    Ted
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    This generator will have GFCI protection on the receptacles that is integral to the generator. This means that if you don’t switch the neutral the GFCI device will trip every time you switch the breaker in the panel.

    This generator will need to be installed as a separately derived system, meaning the neutral will need to be switched in the transfer switch.

    A UL standard for portable generators now requires this.

    [Engine Generators] Engine Generators for Portable Use


    GENERAL
    This category covers internal-combustion-engine-driven generators rated 15 kW or less, 250 V or less, which are provided only with receptacle outlets for the ac output circuits. The generators may incorporate alternating- or direct-current generator sections for supplying energy to battery-charging circuits.
    When a portable generator is used to supply a building or structure wiring system:
    1. The generator is considered a separately derived system in accordance with ANSI/NFPA 70, "National Electrical Code" (NEC).
    2. The generator is intended to be connected through permanently installed Listed transfer equipment that switches all conductors other than the equipment grounding conductor.
    3. The frame of a Listed generator is connected to the equipment-grounding conductor and the grounded (neutral) conductor of the generator. When properly connected to a premises or structure wiring system, the portable generator will be connected to the premises or structure grounding electrode for its ground reference.
    4. Portable generators used other than to power building or structure wiring systems are intended to be connected to ground if required by the NEC.

    I highly recommend that you save a bunch of money and simply use cords to power what ever you need powered by this generator during a power outage. The amount of time used to go to the panel to switch from one circuit to another to keep from over loading the generator will be about the same as moving the cord from one appliance to the other.

    Keep in mind that this generator will not power more than about 25 to 30 amps for any amount of time without damaging the generator output board.
  3. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    JW, where is that info from? Right from UL?

    That changes a lot of things and is pretty absurd if you ask me.
    Switched neutrals from a portable genny??? So Gen-Tran panels, interlocks, and other extremely convenient devices will be rendered obsolete?? Real smart UL. This is push people into doing it the dangerous way.
    Last edited: Dec 3, 2011
  4. Ted M

    Ted M New Member

    Messages:
    12
    Location:
    Northern New Hampshire
    JW: Thanks for the reply.

    I did read your text above with the underling, etc., in previous posts.

    I'm convinced that my Generac XG7000E will have to remain bonded and run as an SDS.

    However, running from cords seems to be a major inconvenience also.

    I'd have to rewire my furnace connections, and the well pump also.

    Some friends of mine in CT were without power for a week.
    If that happened to me I'd like to have some hot water also.
    The XG7000E could run my water heater (with little else).
    Rewiring it for cords would be difficult.

    I'm sure I could wire up an X-Series (neutral switching) transfer box.
    Like you said though, it's a one-time expensive item.

    Ted
  5. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    [
    You are very welcome

    This is what UL mandates and the NEC will reflect this in the near future

    I have been using this method for several years now and it isn’t as bad as it seems. The problem comes when one wants to use the generator for a load bigger than it is designed to carry.

    With the little generator the well is all it could safely pull at once. I hope it is a gas furnace in which case it would be little effort.

    the longest time we were without power was 11 days and we lived through it with little or no discomfort
    It would be a major strain on that little generator to supply a water heater if the elements were 4500 watts. To have anything else even a 100 watt light would be more than it could carry for any amount of time. If you look closely at the manual it states that the rating of the generator is 29 amps continuously and 36 amps surge.

    I have never heard of or seen a X series transfer switch.

    When someone wants to use a generator for optional backup power they would be well advised to size the generator for the load being served. I have been dealing with these small generators for many years now and it has been my experience that the generators just do not fulfill the desires of the user. They are constantly having them repaired or replaced not to mention running outside to restart it after it stalls.

    I would recommend that if you are wanting to use the well, water heater, heat and watch TV while the lights are on then go ahead and spend the upfront money and install at least a 14KW generator that will carry all this load without having to sit in the dark while the water heater heats up. These small generators are not designed to carry this large of a load and to keep it from stalling you will be constantly be running back to the panel to turn something off while something else is on.
    This is not to mention the damage that might happen while using electronic devices such as TV and sound around systems and the like.

    We use two small generators when we have a power failure. One is just for the well as we have horses that require water. The other is for a lamp that is carried from one room to the other as needed.
    We do not watch TV and only connect to the refrigerator and freezer for 30 minutes at a time twice a day. We leave the doors shut so there is not warm air introduced to the inside of them.
    We have gas logs and they do a fair job of keeping us warm. We use this time for some family bonding the way families should bond.
  6. Ted M

    Ted M New Member

    Messages:
    12
    Location:
    Northern New Hampshire
    JW: The Reliance X-Series is new. You can see them on the Reliance site. These panels switch the neutrals also.

    See:
    http://www.reliancecontrols.com/Products.aspx?pl=x_series&c=&f=


    I know the water heater is a large load. 240 volts, 18 amps or so.
    I would have to run it only once a day. Everything else turned off. Have to try it once anyway.
    No problem running up and down stairs to switch things on and off.

    My furnace is oil/air. 120 volts and 12.5 amps.
    House is extremely well insulated. Use 275 gallons of oil a year.
    I'd just run the furnace (only) a few times a day.

    The well pump is rated 230 volts and 4.4 amps.
    Again, I'd just run it when the water tank got low.

    I expect there to be inconveniences when on emergency power.
    There were plenty of times things were inconvenient with no power at all!

    The 7000 running watts will have to do for me.
    Managing the loads properly will be the least inconvenience.
    The heavy load items will just have to be run without anything else on.

    Ted
  7. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
  8. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Thank you for the link. Don’t know why but my mind went to X-10 remote switching devices.

    The problem with the well and the water heater is found in Section 430.22 for the well and 422.13 for the water heater. The inrush current needed to start the well motor might be enough to cause a voltage drop across the circuit board of the generator. The same is true of the continuous load of the water heater load should anything else be on at the same time. Here in lies the danger to your set up.
  9. drick

    drick In the Trades

    Messages:
    392
    Yup. During the October snowstorm I had two HOs who wanted whole house transfers. They both had the unfortunate luck to live in the only town that has an inspector that is wise to the switched neutral and enforces it. As soon as they heard the price they both said they would take their chances with the illegal way. So instead of having two homeowners using an interlock kit they are using nothing. I understand the need to change the code, but it has come at a high price as far as safety is concerned.

    Ted thanks for the link on the Reliance panels. I've been looking for something to replace the non neutral switching Gen-Trans and if its similar cost or even just a little more it could be a potential substitute.

    -rick
  10. DonL

    DonL Jack of all trades Master of one

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    Location:
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    What is the difference in UL listed and UL Approved ?

    The UL Mark is Stuck on a lot of JUNK, I Think.
  11. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    The switched neutral code is something I do not see often and have not seen it very much. I work for a generator service company. I have worked for this company for 18 years. I have done field work and worked on transfer switches and generators of all sizes. We have tied in large portable generators many times to take the place of one that is broken or getting repaired or replaced. Very few transfer switches switch the neutral and just about every generator has the neutral bonded to the frame.

    I just saw a 400 amp transfer switch installed that was permitted and inspected. It is for use with a large generator not yet in place. It has NO switched neutral and was inspected by the towns electrical inspector. His main concern was the grounding system......The final inspection was maybe a month ago.

    We have sold a ton of units for home owners because of the storms this past fall. We sold a lot of Briggs 10-12kw standby units with transfer switches. None of those switches switch the neutral. We are not installing these units ourselves, licensed electricians or contractors are. I have not heard any feedback about this issue from anyone.
    Last edited: Dec 4, 2011
  12. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    And this in no way means that any one of them is installed in a code compliant and safe manner.

    When the neutral is bonded to the generator frame and is not switched there is a parallel path on the neutral and the grounding conductor. This is a BIG no-no and is dangerous even if there has been no reported incident you have heard of. I promise you that I have heard of many incidents of where someone was hurt due to the improper installations of small stand-alone generators and help investigate one fire due to improper bonding while refueling of a generator that was bonded and the neutral was not switched. The person had burns over 30 percent of his body simply because he wanted that stand-alone generator connected to his house.

    As with a lot of people there is a lot of confusion with electrical inspectors when it comes to the earth ground. This is spelled out in 250.4(A)(1) of the NEC and has nothing at all with how a generator works.

    I have spent many hours trying to get these small stand-alone generators outlawed from being connected to premises wiring systems and will continue my fight against such ridiculous setups. They have their place in society and connected to someone’s home is NOT one of them.
    Unless the person using one of these small generators has some knowledge about electricity they are asking for problems. Case in point;
    A lady with COPD and using an oxygen concentrator hired an electrician to install a generator so she would have power for her machine in case of a power failure. The little old lady was on SSI and had a limited income so the electrician installed a 5500 watt generator for backup power.
    This worked out fine as the next door neighbor would come over and set everything up and start the generator for the woman when the power went out.
    Power goes out during an ice storm, neighbor comes and starts the generator and everything is fine. Lady is hungry and has had no breakfast so she goes to make something real quick and a pot of coffee. Some of her medication requires her to take it with food as well as her being a diabetic and requiring her to eat when her blood sugar gets low. The generator stalls and leaves her without any power.
    Neighbor returns home from work and notices that the generator is not running so goes over to check thing out and finds lady in floor. Her blood oxygen got very low and she passed out.
    Thank God she pulls through this ordeal and there was no real harm except she did not have what she thought she had paid for, backup power. This set up was replaced with a 24KW generator so she could have heat during a power failure without worry about it stalling out. With this new setup she didn’t need any help starting the generator as it started all by itself. All this was paid for by the tender hearts of her family and friends and the rebate from the electrical contractor that installed that bunch of bull crap in the first place.

    Those who know me on these forums know that I work side by side with people who are on the Code Making Panels as well as with people from UL and Met Labs. I spend a lot of time at our State Capitol working with the DOI and with NCIAEI on education material for contractors and inspectors. I am continually talking about such issues as the stand-alone generators being connected to premises wiring systems and the dangers involved. This is with some of the greatest minds in the electrical industry and not with someone who thinks they know what they are talking about.
    Most of these units especially those made in the past are not approved for use during inclement weather and not approved for connection to premises wiring systems. This is why the mandate that ALL RECEPTACLES be protected by GFCI so that the connection between a system that is already bonded will cause the GFCI device to open. This forces the switching of the neutral should one be connected to someone’s home. It is a life safety issue and not something that someone thinks they know something about.
  13. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    And I'll keep installing them until such time that I see a written electrical code disallowing them or have an inspector flag one with proper documentation.
    To say they are all inherently unsafe is kind of ambiguous.
  14. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Here it is, 110.3(B) and the link in post #7

    Also see 702.11 for the installation process for connecting one of these self-contained generators to a premises wiring system.
    (A) Addresses a Separately Derived System and requires a ground rod as outlined in 250.30, no exceptions
    (B) Non-separately Derived System allows the grounding electrode of the premises wiring system
    How do we determine the difference between the separately derived system form the non-separately derived system? The bonding at the generator, if the neutral is bonded to the frame it is a separately derived system and will require an electrode to be installed at the generator and the neutral to be switched.

    To connect a stand-alone generator to the premises wiring has rules that must be followed no matter if we see the danger or not.

    250.34 does not require a grounding electrode system for stand-alone generators only if the generator is being used as a stand-alone system with no connection between the generator and the equipment being supplied such as distribution panels such as service equipment. See the Informational Note under 250.34(C)
    There it is in black and white and the rules for using one of these generators as an optional backup system.

    As long as they are being used with cords from the generator to the appliance then there is no violation of the installation instructions and the NEC but the minute that one is connected to a panel then the listing and the NEC takes hold and the requirements must be met.

    And remember that just because an inspector signs off on an installation does not relieve the contractor of liability or at least not here in North Carolina. Should something go wrong the electrical contractor is the one who is gone after not the inspector. Unless it is a case of gross negligence the inspector is protected by the state and in the worst case will only loose his inspection certificate.

    As with the case of the fire in my earlier post the installation had nothing to do with starting the fire but the bonding at both ends of the neutral got the electrical contractor a trip to the licensing board and the inspector was not approached in any way.
  15. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    996
    Location:
    NY State, USA
    110.3(B) says to follow the manufacture's instructions and does not apply IMO.

    All I can say is I am glad you are not my inspector. :)
  16. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    It is only through education that one learns that the way they have been doing things is completely incorrect.

    I am deeply involved with the education of electrical contractors and inspectors here in NC. Over the past years of working with the Department of Insurance, the ones charged with qualifying electrical inspectors in NC, and the NC Licensing Board I have witnessed shear ignorance of the rules outlined by the NEC. I once was stunned by the lack of knowledge but have become accustom to seeing someone that lacks knowledge.

    I have dedicated my life to the continuing education of electrical contractors and inspectors as well as upcoming students in the electrical field. It is my desire to see everyone on the same page when dealing with electrical safety and the proper installation of electrical systems. I am myself a student of the electrical trade and continually learn things that I thought were safe but find out they are not.

    One of my favorite statements is, “just because it works in no way means that it is done in a safe and compliant manner.â€

    It was in the 2002 code cycle that the requirements for portable generators was added to 702 which required them to be grounded (connected to earth) if connected to the premises wiring system, but the language in 250.34 and the FPN has gone unchanged from the 1999 code cycle.

    As long as the stand-alone generator is being used without a connection to the premises wiring no earth connection is required. Once the stand-alone system is connected to the premises wiring then a connection to earth is required either as a separately derived or a non-separately derived system. At any rate the bonding must be done at one place or the other not at both places.

    UL has stepped forward with their Standards for the manufacturing of stand-alone generators and now require that ALL 15, 20 and 30 receptacles on these generators be protected by GFCI protection.

    The NEC also has come forward with this requirement to go into effect on January 1, 2011 590.6(A)(3) Receptacles on 15-kW or less Portable Generators. All 125-volt and 125/250-volt, single-phase, 15-, 20-, and 30-ampere receptacle outlets that are a part of a 15-kW or smaller portable generator shall have listed ground-fault circuit-interrupter protection for personnel.

    There is a big difference in temporary power and optional standby power. These stand-alone generators are designed as temporary power and if used as optional standby power must follow the rules outlined in 702. The grounding requirements outlined in the note following 250.34(C) states that should a portable generator be used as optional standby power it must be connected to earth and again in 702.

    One thing to keep in mind is that portable generators include many different types of generators and is not limited to the stand-alone generator.
  17. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,147
    Location:
    Houston, TX

    You have done Great work JW, and that is one reason that Complying to Code and Insurance is so expensive.

    Keep up the Good Work...
  18. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    I did not mean to say that I don't believe there could be a safety issue here and I will site an example that I recently had occur.....

    We took in many portables during the recent stroms issues in my area. Probably 20-30 various small portables that lost AC output. Normally I would not devote much time to trying to fix these smaller units as it is generally not a profitable endeaver.....but I did repair quite a few and condemed a lot also as repair costs would be prohibitive...parts-labor...added up to too much money for such a smallish unit....

    Usually I find bad brushes....or a blown capacitor or a bad voltage regulator...easy fixes, just find the parts somewhere.

    Sometimes it's a bad rotor or stator and that gets very pricey.....

    One machine had no output.....a 5KW unit I think it was. Don't recall the brand. I could not find a reason for it NOt to have output. It was the design that had no brushes.....diodes on the rotor and a run capcitor. I desoldered the diodes and tested them....good.....tried a similar rated capcitor....still no output. Did ohm tests on the stator and all seemed normal. Most small generators have 4 wires coming out of the stator and depending on how they are connected it might be 120/240 or 120 only........This machine was 120/240 and had connectors between the outlet panel and the stator connections. I was thinking something on the panel was shorted so I disconnected the panel from the staor leads. I checked all the wiring on the outlet panel....all good. I checked the outlets....nothing shorted.

    I started the generator and probed the staor connections......It had NORMAL output....120/240 all fine.....but if I tried to connect the leads to the panel.....there was a dead short to the output and obviously a serious arc and the engine/generator grunted down indicating a dead short on the output....

    If the connectors were hooked back up with the engine off and than started ....iit again had no output.....


    So the bottom like is the stator was shorted to the body of the generator......or at least that was my take on it....

    I sold the owner a new unit......

    This was the first time I had ever run acorss this scenario and it may have happened before but it was a new one on me.....

    I have brought this neutral/ground bonding iussue up many times at work as it is one I am really not totally clear on.

    I have read JW's posts many times trying to get a better understanding of this issue. It still is not clear to me. 4 wire dryer cords.....and seperated gounds and neutrals in sub panels and out buildings.......I would like to understand this better and be able to explain it better....

    After the recent storms.....I watched a major NewYork network broadcast that covered generators and hooking them up for homeowners. It was so inaccurate as far as what an electrician would charge to do this work it was redciculous and added to the problem.....Gave people the idea it was an easy inexpensive and simple thing to do. I broughta generator home for my next door neighbor. He was without power for 4 days. I lent him my small generator. I told him to use extension cords for his unit and just make a good cord for it.....
    Last edited: Dec 4, 2011
  19. Rich B

    Rich B DIY Senior Member

    Messages:
    283
    Location:
    New Jersey
    I should add....

    I was out on a few jobs recently and one was for one of our generators that was tied into a building and during the snow storm.....they lost power and the generator did not start. No one knew it did not start for a few hours. They were on their UPS system and eventually the whole place went down. Oh....it was just the local office of emergency management for our area. They handle all 911 calls.....and it is also the police and fire academy where they train everyday....You'd think someone in such a place would realize they were on UPS and know the generator wasn't running.....All it takes is the flip of a toggle switch on the machine to start it! Nope.....4 hours later all their computers hard crashed and the county dispatch system went black in the middle of the storm.......

    Their generator has been nothing but problems from day one and ours was hooked in as theirs was likley to fail and had been worked on numerous times in an effort to rectify it's issues. Now they are ripping it all out and a new building is being construced....and another new generator will be installed....bigger and better....

    The no start condition for our unit was never really clear as it should have started.....but didn't. The remote start connectiuons were made by their electrician.....and should really have got the job done. He added a simple relay that was not really needed. We eliminated it and after a couple hours of various wiring attempts...it was tested and worked. We did an ACTUAL power interruption....and transfer. The reason I bring this entire episode up.....The transfer switch had a SWITCED Neutral...I noticed it right away when I started working in the switch......
    Last edited: Dec 4, 2011
  20. jwelectric

    jwelectric Electrical Contractor/Instructor

    Messages:
    2,534
    Location:
    North Carolina
    Do you understand parallel paths?
    If the EGC is bonded on both ends to the neutral then the equipment grounding conductor is carrying current just like the neutral.

    A couple of years ago a good friend of mine was repairing the EMT between two panels in a ware house. This was a run of 2 inch pipe that carried the feeders from the main to a remote panel about 50 feet away. The EMT was the equipment grounding conductor and the remote panel did not have an isolated neutral.

    A stack of boxes had toppled over and broke the connection at one of the couplings. When Fred walked up to the pipe and grabbed the pipe, one side of the coupling with one hand and the other pipe on the other side of the coupling in the other hand, was the last thing he remembered until they were loading him in the ambulance.

    There is a major concern with having these small stand-alone generators connected to the premises wiring system with the neutral bonded to the frame of the generator and again having the EGC and neutral bonded at the service equipment.

    Just a few miles away a man built a pole barn for his horses. He had finished all the wiring but had not called for an inspection so there was no power on the building.
    He came home from work and noticed that the ground was wet so he called his plumber to come and fix the problem at the barn. They back fed a breaker from the 30 receptacle on the generator to have lights to fix the pipe that had frozen and ruptured.

    After all was repaired the plumber went to turn off the generator and when he leaned over and touched the frame with wet feet in a puddle of water from the busted pipe he got his world rocked. The frame of the generator and being just inches from the grounding electrode at the barn completed the parallel path which caused him to remember his religion. He completed the third parallel path for current to follow.

    In the post above about the man that was burnt while refueling, he swore he felt current. It is possible as the neutral and equipment grounding was bonded at both ends.
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