Predator Standby Genertor - Bonded Neutral?

I bought a Predator Generator and plan to install an interlock on my main panel with an outside plug to backfeed the power to my house. Based on my findings I need to break the neutral bond on the generator since the Main has the neutral bonded. I took the cover off my generator and it doesn't appear to me the neutral is bonded. I thought if it was bonded it would have the neutral and ground tied to the same lug on the engine. Can anyone look at this picture and confirm if the neutral is bonded?

 

Try calling the manufacturer, they usually have technical people at the plants to answer this type question.

 

I would not dig into the generator for the purpose of unbonding neutral and ground there.

If the manufacturer or the generator instructions did not have anything about unbonding neutral and ground, I would leave it as-is and hook it up to the house inlet receptacle anyway.

Nothing bad will happen in this particular instance with neutral and ground bonded in two places.

 

Not an electrician, and I am sure they will chime in, but its not code to have two bonds...

Electrical code.....

250.24(a)(5)

 

Determining if the generator has a bonded neutral is easy. You can use a simple continuity tester or a multimeter set to ohms. Place one probe in the longer slot of the 120 volt receptacle and the other probe in the equipment ground U slot (or to the external ground connection) and see if there is continuity or minimum ohms resistance. If yes, then the neutral is bonded. If no, then the neutral is floating.

Having a neutral-ground bond at the generator AND in the service panel will cause the neutral currents to return to the generator over BOTH the neutral AND the equipment ground conductors. While the risk is low this IS contrary to the National Electrical Code. Not connecting the equipment ground conductor at either the generator OR the house inlet connection removes this parallel path with a minimal danger. It still is not code compliant but the danger is pretty much limited to a ground fault condition in the generator-to-house interconnect cable. Taking pains to protect this cable from damage (don't lay it across a driveway and drive on it) minimizes any danger.

 

Thanks guys and Furd I'll try to figure out if I can run your test. If it is a neutral bond then I'll have to figure out how to remove it.

 

If the neutral and equipment ground are bonded then leave it that way. If they are not bonded there are easy methods that can be used to make that bond. Use a neutral switching transfer switch or transfer panel at the house (best solution) OR do not connect the equipment ground of the interconnect cable.

 

Furd, the goal is to identify how to properly handle the neutral bonded generator using an INTERLOCK and meet code. Based on my research, I need to break the neutral bond on the generator to ensure only one bond exists which is in the main. I don't see the need for a transfer switch if I know what my loads are and manage them correctly with the Interlock. Plus I will have to buy a 3 pole transfer switch to manage isolate the neutral bond. I don't see a need for this expense and adding all the additional wires a circuits when an interlock on the main can make this very simple. I just want to meet code to ensure safety is maintained along with not voiding my insurance on my home.

 

I have given you the the information, interpret it any way you desire. If you do not pull an electrical permit and have it inspected according to the code adopted in your LOCAL jurisdiction then you WILL be in violation. If you have no local, regional or state electrical codes then obviously you will not have a code problem.

 

I plan to have an inspection but I've heard this means nothing from a liablity standpoint. That's why I'm paying to have the Electrician from my Electric company set it up but I'm trying to find the right way to do it because the Electrician seemed to not be concerned about the neutral bonding. He stated since the 220 had 4 wires there was no issue with bonding. This scared me. Appreciate your help.

 

Unless the electrician is a bona fide business entity apart from his job with the utility it is doubtful that he would have any liability insurance. Also, unless he was working as an employee of the utility when he did the work on your system it is unlikely the utility would have any liability either.

This IS a straightforward installation, no "rocket science" involved. While the utility DOES make rules for what needs to be done prior to them providing electrical service it is really the job of the governmental electrical inspector to determine if your installation meets the requirements of the local code.

Many thousands, if not tens of thousands, of generator installations have been, and will continue to, be made with bonding at both the service panel AND in the generator. They work and while definitely not in strict compliance with the national code neither are they a serious hazard in my opinion. While the risk is slight it DOES exist and there is no question that the installation does not meet code. The ONLY time that such an installation would absolutely not work is if the generator has a GFCI circuit breaker prior to the output receptacle. Some generators will have 120 volt GFCI receptacles but the 240/120 volt twist-lock receptacle will NOT have GFCI.

I have stated this many times over the years. Connect the power inlet fitting at the house in accordance with ALL codes in regards to equipment grounding EXCEPT with the equipment ground terminal of the inlet fitting itself. This means to run two "hot" conductors from the interlocked "generator" circuit breaker to the two hot connections (X and Y) on the inlet fitting. Run a neutral conductor from the neutral bus in the panel to the neutral (N) connection on the inlet fitting and run an equipment ground conductor from the neutral bus to the enclosure of the inlet fitting. Do NOT make any connection to the equipment ground (G) connection on the inlet fitting. This will isolate the equipment grounding conductor in the interconnect cable (generator to house) and prevent any parallel currents from flowing in the equipment grounding conductor. This requires no modification of the generator nor of the interconnect cable. Absent a switched neutral in the service panel this is the best method available. It is NOT code compliant but the risk of any danger is extremely low.

 

I've yet to see a power company who employed electricians, not even the rural coops I have had experience with have electricans, they generally only employ linemen. It sounds as if you are hiring a lineman who does part-time electrical work and may not be familiar with generators.

 

Highlt, I am not familiar with that particular band, but most portable generators bond the neutral to ground via a small jumper wire on one of the receptacles. Look for an extra wire between the ground and neutral terminals on the outlets. Oh, and if you are going to use the unit when it is not connecto to the house, you need to replace the jumper.

Post a picture of the back of the outlets if you can't find it.

 

A few more questions since I've read some other posts.

1. Is the neutral bonded generator only an issue if you have GFCI circuits? I'm interested from a code perspective.

2.Does a neutral bonded generator without GFCI still require the bond to be broken?

If question 2 is yes, then I assume my options are the following.

1. Interlock - Break the neutral bond on generator to prevent two bonding points. Only option I see using an Interlock.

2. Transfer switch - Leave bond on generator and have 3 pole Transfer switch to handle neutral.

3. Transfer switch - Break bond generator and have 2 pole transfer switch.

 

1. From a code perspective the GFCI has no bearing on the issue. From a practical standpoint, if there are GFCI's on the generator itself, a circuit bonded at the panel and generator will cause to GFCI's to immediately trip because they will sense the current on the ground conductor.

2. From a code perspective, yes. From a practical standpoint, no.

 

Thanks for your input Auger. I'm torn between buying an Interlock kit versus a 3 pole transfer switch. The cost is about the same but the flexibility of the Interlock allowing me to control anything is nice.

 

IMO I would break the bond at the gen..... ( Im not an electrician)

My gen came with a floating neutral...When I plug to the inlet to my transfer switch I am bonded at the panel

If I use the gen stand alone the code says the gen needs to be bonded.. I use an edison plug to do this...( Although IMO its safer to run a gen with a floating neutral stand alone, but thats not what code says)

I do use this if I use the gen for the RV.. The RV neutral and ground are not bonded at the RV panel...

 

Auger-

I managed to locate and break the bond on the Predator. It was inside the control module on the ground lug. I've attached a picture of it for anyone else who might want to know how to break the bond for a Predator Generator.

I plan to proceed with installing a 30 amp breaker in my my main panel with an Interlock. Since the neutral is floating now there will be only one bond in the system. This generator will only be used when hooked to the house electrical system but I will have a BIG note stating FLOATING NEUTRAL DO NOT USE STAND ALONE. This should be safe and meet code now. Waiting for official report from Electrical Inspector. Thanks for your help.