Ground Neutral Plug use?

[Gliddenwoods]

I want to charge my Oliver with  Blueitti (sp?) battery "solar generator". 

Is it correct that I need to plug a "ground neutral plug" in one of the Bluetti outlets to make it work correctly?

[FloraFauna]

I needed to do so with my Champion generator.  

[Snackchaser]

I've never heard of a Blueitti.  However there are a similar issues with a  Jackery.  They have what's called a floating neutral.  Also common in some generators.  So yes, a floating neutral requires a neutral to ground bonding plug.  Otherwise the Electrical Management System (EMS) will see it as an open ground.  

But there is a problem.   Many  (if not all) of these power packs have no reference to ground what-so-ever.  So the "u-ground" pin hole of the receptacle is not connected to anything, it's just an open hole.  So a neutral to ground bonding plug wouldn't connect to anything in the ground pin hole, and it won't work.  

Now that I've confused everyone, including myself, there is a bypass trick.  Use a 1-outlet to 3-outlet adapter, or an extension cord with a "Wye" that provides 3 extra outlets to plug into.  Plug the neutral to ground bonding plug into one the extra outlets to effectively bond the neutral and ground... despite there being no ground on the power pack.   Cool huh.  

This is one of many reasons to have a $10 plug-in circuit tester, the ones with three lights that show various conditions such as open grounds.  I recommend you test all circuits when rigging such power supplies.

Cheers!  Geoff

[Gliddenwoods]

47 minutes ago, FloraFauna said:

I needed to do so with my Champion generator.  

Into an outlet in the Oliver or in the generator?

[Gliddenwoods]

4 minutes ago, Snackchaser said:

I've never heard of a Blueitti.  However there are a similar issues with a  Jackery.  They have what's called a floating neutral.  Also common in some generators.  So yes, a floating neutral requires a neutral to ground bonding plug.  Otherwise the Electrical Management System (EMS) will see it as an open ground.  

But there is a problem.   Many  (if not all) of these power packs have no reference to ground what-so-ever.  So the "u-ground" pin hole of the receptacle is not connected to anything, it's just an open hole.  So a neutral to ground bonding plug wouldn't connect to anything in the ground pin hole, and it won't work.  

Now that I've confused everyone, including myself, there is a bypass trick.  Use a 1-outlet to 3-outlet adapter, or an extension cord with a "Wye" that provides 3 extra outlets to plug into.  Plug the neutral to ground bonding plug into one the extra outlets to effectively bond the neutral and ground... despite there being no ground on the power pack.   Cool huh.  

This is one of many reasons to have a $10 plug-in circuit tester, the ones with three lights that show various conditions such as open grounds.  I recommend you test all circuits when rigging such power supplies.

Cheers!  Geoff

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.bluettipower.com/collections/solar-generators%3Fsrsltid%3DAfmBOorYwy_9QQeUU5f8w-gieqaqxkTNeuxvTgwk7-IXFxfPsFHY-ShT&ved=2ahUKEwiZwsmvkJKVAxXDmisGHevaGgUQFnoECBsQAQ&usg=AOvVaw1JV2q4OjzofNCgrtpnFEQd

[Steph and Dud B]

37 minutes ago, Gliddenwoods said:

Into an outlet in the Oliver or in the generator?

A generator. There is another option in a pinch. You can use the Bypass switch on your EMS control panel (ours is in the "attic" over the bed). This will keep the EMS from blocking power from the "ungrounded" generator, but it will also remove all protection provided by the EMS. However, power from the Bluetti is already supposed to be clean, right?

[Gliddenwoods]

27 minutes ago, Steph and Dud B said:

A generator. There is another option in a pinch. You can use the Bypass switch on your EMS control panel (ours is in the "attic" over the bed). This will keep the EMS from blocking power from the "ungrounded" generator, but it will also remove all protection provided by the EMS. However, power from the Bluetti is already supposed to be clean, right?

That sounds dangerous and I could fry something; yes?

[Steph and Dud B]

32 minutes ago, Gliddenwoods said:

That sounds dangerous and I could fry something; yes?

Not really. Lots of people have RVs with no EMS system at all. The EMS cuts off power to your rig if the voltage is too high/low, the wires are not connected properly, or the source has the wrong Hertz (cycles per second). Cheap generators can have all of those problems. Shore power can be wired incorrectly or have voltage issues. Check your specs, but most new Bluetti power stations use a pure sine-wave inverter. That means the power should be "clean" enough for sensitive electronics. Almost certainly safer than plugging into shore power at a campground.

I got this from an AI search: "Bluetti power stations are very safe for sensitive electronics. All Bluetti units use pure sine wave inverters. This mimics the clean, stable power of a standard wall outlet, preventing screen flickering, overheating, and data loss for devices like laptops, TVs, and CPAP machines... Avoid ECO Mode: If using a Bluetti solar generator, users on PowerEquipmentForum suggest turning off the "ECO mode" for the most stable and reliable power delivery to sensitive electronics."

[FloraFauna]

9 hours ago, Gliddenwoods said:

Into an outlet in the Oliver or in the generator?

Into the outlet on the generator.  I believe this is an artifact of the lack of a grounding rod and grounded electrical system on the trailer (which would be totally impractical).

[CRM]

13 hours ago, Gliddenwoods said:

Into an outlet in the Oliver or in the generator?

Never at an outlet. This is known as a "bootleg ground" and can cause dangerous situations.

[Snackchaser]

The bonding plug needs to be at the source -- the Bluetti or generator outlets.  Not an outlet in the trailer.  

Because the Bluetti outlet has nothing connected to the ground, the bonding plug cannot join the ground and neutral.  Therefor a one-to-three outlet adapter can be plugged into the Bluetti, one of the three adapter outlets gets the bonding plug, another gets the trailer feed cord, and the third is a spare.  That effectively bonds the ground and neutral.

Bonding at the power source has always been required by code, these power packs just add a new dynamic.

Someone had an idea to use the EMS bypass "in a pinch."  This isn't risk free, but it would be fine for getting the lights on while finding the bonding plug.  The EMS is actually protecting the trailer from an un-bonded neutral that the bonding plug fixes.  

Keep in mind that these power supplies are perfectly fine for single power cord loads as designed.  They are not designed to be connected to a trailer where the wiring system assumes a bonded supply.  

Cheers!  Geoff 

Edited 11 hours ago by Snackchaser

[Steph and Dud B]

3 hours ago, Snackchaser said:

Keep in mind that these power supplies are perfectly fine for single power cord loads as designed.  They are not designed to be connected to a trailer where the wiring system assumes a bonded supply.  

Interestingly, Bluetti makes units with 30, and even 50A, RV receptacles specifically for plugging in an entire RV.  Not sure if that's what the OP has, or how they handle the ground circuit. 

[Gliddenwoods]

1 hour ago, Steph and Dud B said:

Interestingly, Bluetti makes units with 30, and even 50A, RV receptacles specifically for plugging in an entire RV.  Not sure if that's what the OP has, or how they handle the ground circuit. 

[Snackchaser]

1 hour ago, Steph and Dud B said:

Interestingly, Bluetti makes units with 30, and even 50A, RV receptacles specifically for plugging in an entire RV.  Not sure if that's what the OP has, or how they handle the ground circuit. 

That’s a great comment.  In reality, the manufactures are producing these things faster than the regulatory bodies can keep up.  Merely disclosing a floating neutral is enough to keep them off the hook for now at least.  This was first mandated for the generator industry, and It’s ultimately the installers responsibility for how they are connected and used.   

These power packs have a least off-set the risks with built-in GFCI’s for personal shock protection, but that does not satisfy the long standing rules for bonding that the trailer industry must follow.

This is directly related to the trailer “hot-skin” issue that was bandied around for years.  They recently codified long overdue requirements for trailer Ground Monitor Interrupters (GMI) that will be phased in over the next few years.  Similar to the EMS (except it can’t be by-passed), the GMI’s will prevent the use of non-bonded power supplies, and it will be non-optional for new trailers.

We watch with interest how this story fully evolves!

Cheers!  Geoff

[Tom and Doreen]

47 minutes ago, Snackchaser said:

This is directly related to the trailer “hot-skin” issue that was bandied around for years. 

Could get a little exciting with an Airstream! On the plus side an Airstream probably would make a pretty good Faraday cage! 

[Steph and Dud B]

24 minutes ago, Tom and Doreen said:

Could get a little exciting with an Airstream!

I got a little zap off our aluminum skinned trailer when it had an open ground once. Didn't hurt me, but definitely got my attention.

[Steph and Dud B]

For the electrical engineers out there: does using a bonding plug on a generator with a floating ground actually do anything to improve safety? There's still no actual connection to earth ground. I always thought of a household ground as a way for stray current to be shunted safely to earth ground rather than finding a path through a person. Why are earth ground and neutral tied together at a household panel? What good is bonding them together without an earth ground?

[CRM]

3 minutes ago, Steph and Dud B said:

For the electrical engineers out there: does using a bonding plug on a generator with a floating ground actually do anything to improve safety? There's still no actual connection to earth ground. I always thought of a household ground as a way for stray current to be shunted safely to earth ground rather than finding a path through a person. Why are earth ground and neutral tied together at a household panel? What good is bonding them together without an earth ground?

Yes, using a bonding plug makes it safer by providing a low resistance path back to the generator to trip the breaker in the generator if a short to the metal case of an appliance inside the RV or the generator itself occurs. 

When it comes to the ground rod system in a residential system, it is there for voltage stabilization and surge dissipation, not to trip breakers. In fact, if the neutral and grounding electrode system are not bonded in the service panel you could connect a hot conductor straight to the ground rod and it will not trip the breaker. You need the bonding in the panel to provide a path back to the transformer for that to happen. You get that path when the ground and neutral are bonded in the service panel, completing the circuit back to the utility transformer's neutral point.

[Steph and Dud B]

6 minutes ago, CRM said:

Yes, using a bonding plug makes it safer by providing a low resistance path back to the generator to trip the breaker in the generator if a short to the metal case of an appliance inside the RV or the generator itself occurs. 

Ok, I think I got that, thanks. So why are so many generators built with floating grounds?

[CRM]

29 minutes ago, Steph and Dud B said:

Ok, I think I got that, thanks. So why are so many generators built with floating grounds?

To make sure that if the generator is connected to a residential service that will always be code complainant. You can't have more than one neutral/ground bond in a system, and since a residential main panel is already bonded you would be violating code and creating a possible hazardous condition. 

Edit- I shouldn't have said "always be code compliant" since there are ways to connect a generator to a residential system that will violate code even if you use a floating neutral  generator. 

 

Edited 2 hours ago by CRM