Will GFCI outlets work with unbonded generator?

[trailertraveler]

I know the issue of bonding the ground and neutral on small generators has been discussed before. I did a search and found numerous discussions but did not see any mention of any impact on the function of the GFCI outlets. I saw mention of GFCIs not working (not resetting) on another internet discussion but it was not specifically an RV forum. I know that my Surge Guard will not pass the power without the ground/neutral bond plug. I have also seen various opinions on whether it is necessary to use a grounding rod when powering the RV. There was one comment about connecting the grounding lug on the generator to the frame of the trailer, but it was not clear whether this was instead of or in addition to a grounding rod. Several years ago I asked Yamaha about using the bonding plug and they recommended against it. South Wire, the manufacturer of Surge Guard, sells a bonding plug. Discussions on the internet range from never use an unbonded ground generator to power an RV to bonding is not necessary if no EMS system is in use. Any comments, references, suggestions would be greatly appreciated. Also, are there compelling reasons to use Surge Guard when on generator power?

[Kirk W]

11 minutes ago, trailertraveler said:

but did not see any mention of any impact on the function of the GFCI outlets.

There is no effect on the operation of a GFCI. They compare the current through the hot lead to that returning via the neutral lead and the power source is not a factor.

11 minutes ago, trailertraveler said:

South Wire, the manufacturer of Surge Guard, sells a bonding plug. Discussions on the internet range from never use an unbonded ground generator to power an RV to bonding is not necessary if no EMS system is in use. 

This is a totally different issue and has no relationship to the operation of a ground fault. The Surge Guard or Progressive-EMS are both designed to protect your equipment from electrical issues that take place outside of your RV and keep them from entering the RV. A GFCI protects you from an electrical problem that takes place in some device which you have connected to that outlet or one of the downstream outlets that it protects. They serve entirely different functions with no effect of one on the other. 

Edited August 8, 2021 by Kirk W

[trailertraveler]

58 minutes ago, Kirk W said:

 

1 hour ago, trailertraveler said:

South Wire, the manufacturer of Surge Guard, sells a bonding plug. Discussions on the internet range from never use an unbonded ground generator to power an RV to bonding is not necessary if no EMS system is in use. 

This is a totally different issue and has no relationship to the operation of a ground fault. The Surge Guard or Progressive-EMS are both designed to protect your equipment from electrical issues that take place outside of your RV and keep them from entering the RV. A GFCI protects you from an electrical problem that takes place in some device which you have connected to that outlet or one of the downstream outlets that it protects. They serve entirely different functions with no effect of one on the other. 

Thanks for the responses Kirk!

I understand that I raised two different issues. Actually three, including use of a grounding rod. I was interested in the reasons for/benefits of using the bonding plug, reasons to use the Surge Guard when using the generator and the need for a grounding rod.

Sorry if my original post was not clear.

Edited August 8, 2021 by trailertraveler

[Kirk W]

1 hour ago, trailertraveler said:

Also, are there compelling reasons to use Surge Guard when on generator power?

That depends on your faith in the generator that you use. The SG will protect your RV from over/under voltage which is possible but rare. While I wouldn't say that it is compelling, since you paid the money to buy the SG, why not use it? 

The ground rod use is a different issue. Your RV is insulated from the ground by it's rubber tires. Ground roads are used for utility generators because the structures that they supply electricity to are all of them connected to earth ground and the combination adds a safety factor. But if you use a ground rod with your generator for it to do anything at all you must also use a ground rod for your RV.

[oldjohnt]

On 8/8/2021 at 8:09 AM, trailertraveler said:

I did a search and found numerous discussions but did not see any mention of any impact on the function of the GFCI outlets.

TrailerTraveler, GREAT questions, while Im long retired and rusty from my days as a Power Distribution Design Engineer I will offer my professional opinions and answers  

1) The GFCI works by sensing the current flowing out the Hot versus being returned by the Neutral. It DOES NOT sense or measure  current in the Equipment GroundiNG Conductor,  it does NOT pass through the Torroid Coil . There's ONLY the two wires Hot and Neutral passing through the GFCI's Torroid current sensing coil.  THEREFORE it still works with or without Neural Ground Bonding,,,,,,, or using a Floating Neutral,,,,,,,,or using a Genset or utility power source. The GFCI isnt concerned with or monitoring the equipment ground conductor ONLY Hot and Neutral...It still works regardless ..........

 

On 8/8/2021 at 8:09 AM, trailertraveler said:

I have also seen various opinions on whether it is necessary to use a grounding rod when powering the RV. There was one comment about connecting the grounding lug on the generator to the frame of the trailer, but it was not clear whether this was instead of or in addition to a grounding rod.

 

On 8/8/2021 at 8:09 AM, trailertraveler said:

 

 

On 8/8/2021 at 8:09 AM, trailertraveler said:

 

 2) Im rusty on the latest NEC but can tell you this.  Ifffffffff a portable genset is configured as a SEPARATE DERIVED SYSTEM it is required to be bonded to a proper GROUNDING ELECTRODE such as but not limited to driven into earth ground rods SUBJECT TO AN EXPEPTION its not a requirement IFFFFFFF the genset is used to power up portable plug and cord connected tools THAT ARE PLUGGED INTO THE GENSETS ONBOARD MOUNTED RECEPTACLES

 ONBOARD RV GENSETS: In the case of onboard gensets, the iron conductive frame of the RV suffices for and can be used as a  "Grounding Electrode" IE you dont need to drive a ground rod when youre in your RV running off its onboard genset.  You can if you like. 

Sooooooo YES use the frame as a Grounding Electrode for the Genset BUT no earth ground rod is required. Typically an onboard RV genset is configured with a BONDED (NOT Floating) Neutral and such is bonded to the RV's frame which serves as the Grounding Electrode. HEY if you feel good go ahead and drive a rod and connect to the RV neither me nor the NEC are stopping you 

NOTE some portable gensets come from the factory with  A BONDED NEUTRAL, others with a A FLOATING NEUTRAL for good reasons I could explain if needed. As you know an EMS will throw a fault if theres no NG bond which is why a bonding jumper can be used to correct for a genset that has a Floating Neutral so the EMS works. Again a GFCI still works regardless  

 

On 8/8/2021 at 8:09 AM, trailertraveler said:

Several years ago I asked Yamaha about using the bonding plug and they recommended against it. South Wire, the manufacturer of Surge Guard, sells a bonding plug. Discussions on the internet range from never use an unbonded ground generator to power an RV to bonding is not necessary if no EMS system is in use. Any comments, references, suggestions would be greatly appreciated. Also, are there compelling reasons to use Surge Guard when on generator power?

WOW that opens several cans of worms lol I will try to be brief

 1) If a portable genset comes with a Floating Neutral that's because its safe and NEC proper based on how many poles and how the Transfer Switching is configured, if you connect utility and genset Neutrals together, and what you're powering (house, RV, tools etc)  SO IF YOU BOND THERE MAY BE AN NEC VIOLATION AND SAFETY PROBLEM  They will recommend NOT bonding, there can be ONLY ONE NG BOND. HOWEVER an RV panel unlike a home panel uses separate insulated and isolated Neutral and Ground busses THEREFORE its okay to create a NG bond in a floating genset used to power an RV (subject to the above) even if NOT to power your home TWO VERY DIFFERENT THINGS 

2) Grounding and Bonding. There's a lot of old wives tales and mis information and lay person non engineer non electrician info out there on that complex topic I CANT EXPLAIN THE NEC AND A LIFES WORK HERE LOL so will just offer this based on my training and experience as a Power Distribution Design Engineer  NOW DO AS YOU WISH........ 

 For an onboard RV genset (remember its panel does NOT connect N and G like a home)  I would use a BONDED NEUTRAL and also bond to the RV frame as a Grounding Electrode.

For a portable genset on the ground  TO POWER AN RV I would BOND N and G and per the NEC use a ground rod but most don't do that nor have I for short term use. For home its different but Im not going into that here it would take an entire library lol.

Floating gensets are NEC safe and proper in certain circumstances, bonded in others

NOTE those who think driving a rod and connect to the RV since its on rubber wheels protects a whole significant amount against lightning may not understand the nature of things. The gazillion volts amps and energy lightning can produce are no match for a few inches of rubber tires YEAH RIGHT. Earth grounding of the Neutral is protection against surges and spikes and to keep the gird at a common low voltage reference.

SURGE WHEN USING GENSET  Sure use it is fine IFFFFFF genset has a bonded Neutral. However the chances of a major high energy spike or surge on the utility IS FAR LESS ON A GENSET so theres much less risk when using your own generation. Use on genset if you like......

 When browsing the net for info see if its from lay persons or experts or technicians or engineers before making what may be a life or death decision and remember Bonding and Floating and earth grounding and RV versus home and transfer methods and how  many poles are switched (Hots and Neutrals switched or Neutrals tied together???? ??) matters.

I would BOND N & G on an onboard RV genset and connect to the frame.......There is a place and reasons why and NEC for a Floating system is required which I'm not trying to cover here,,,,,,,Use an EMS on genset if you like,,,,,,,No earth rod is required if done as above on an RV but you can if you like but don't think that helps much in a lightning strike because you're on rubber YEAH RIGHT 

PS FYI If you use a portable genset to feed your home and tie genset and utility Neutrals together AS TYPICALLY DONE  .....You use a FLOATING genset and tie the EGC to the gensets frame HOWEVER if you switch Neutrals and dont bond them together, use a Bonded Genset as the RV N and G are NOT bonded together and per NEC attach a Grounding Electrode such as a rod into earth.   The reason Yamaha says NOT to bond is because if you do it may violate the NEC !!!!!!!!!! They cant know how you use it. 

PS FYI You for sure want the RV frame (just like all other non current carrying metallic boxes or enclosures etc) bonded to the Equipment Grounding Conductor in case there's a short energizing the frame YIKES   Hot Skin  can be a killer and simply alone driving a ground rod to the RV may not be enough to prevent electrocution !!!!! TIE THE FRAME TO THE EGC

PS FYI the use of a ground rod on a stand alone portable generator to power an RV has nothing to do with use of a ground rod for the RV. Using a Ground Rod where necessary when configuring a portable genset in accordance with the NEC as a Separate Derived System doesn't know or matter if you attach the RV frame to another ground rod or not !!!!!!!!!! Yes you can drive a rod for the RV if your wish or NO you don't have to. Neutral Ground Bonding IS NOT THE SAME as earth grounding of the Neutral. You can Bond but NOT ground, those are two different things.  Just because you use a Ground rod on a portable genset as required for a Separate Derived Source  DOES NOT mean you need a ground rod on the RV. Typically you DO not drive a ground rod and attach to an RV frame REGARDLESS if you use a Bonded or a Floating portable genset to power the RV

PS FYI if an RV frame gets in contact with a live hot wire and its NOT bonded to the Equipment Grounding Conductor (as it should be) so the breaker trips, it can remain energized and electrocute someone who touches it. HOWEVER even if if a ground rod is attached to the hot skin the resistance of the earth is too great to allow enough current to trip the breaker so the skin remains hot and can electrocute someone EVEN IF RV IS ATACHED TO A GROUND ROD !!!!!  

 THERE CAN ONLY BE ONE NEUTRAL GROUND BOND

  PS if you see different opinions on this subject and cant decide which to follow CONSULT MIKE HOLT

 Electrical Training Solutions |Mike Holt Enterprises

Those who agree with him are most likely RIGHT those who disagree likely WRONG in my opinion

 Out or time I have to run ask questions later

 

 John T  BSEE,JD Retired Power Distribution Design Engineer

  

   

 

Edited August 11, 2021 by oldjohnt