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[Debbie Dunkley]

I will be providing sound and generators for a smallish show this coming weekend...I hope everyone behaves...

Because of this I went on my usual Googling trip and I have a question.
I will be using a Yamaha Ef3000 (PA) and a Yamaha EF2000 (backline). Both generators have open neutrals.
If I will be grounding my generators (copper rod and together), would there be any benefit to me to use neutral/ground plugs ( like the one Mike Sokol recommends) to bond them to their frames?
bonding plug

[frank kayser]

I will be providing sound and generators for a smallish show this coming weekend...I hope everyone behaves...

Because of this I went on my usual Googling trip and I have a question.
I will be using a Yamaha Ef3000 (PA) and a Yamaha EF2000 (backline). Both generators have open neutrals.
If I will be grounding my generators (copper rod and together), would there be any benefit to me to use neutral/ground plugs ( like the one Mike Sokol recommends) to bond them to their frames?
bonding plug

Quick question, Debbie
Have you used the grounding plug in the past?  Ever?
I know I've hooked to 120v gens where I had 60v on hot, and 60v on neutral.  My Honda 1000 is also wired that way.  If it is, grounding plug should not be used.
Congrats on openiong a show!
frank

[Debbie Dunkley]

Quick question, Debbie
Have you used the grounding plug in the past?  Ever?
I know I've hooked to 120v gens where I had 60v on hot, and 60v on neutral.  My Honda 1000 is also wired that way.  If it is, grounding plug should not be used.
Congrats on openiong a show!
frank

Hi Frank - no I have never used a grounding plug.
I came across the threads discussing this on different forums and discovered this device. I took it seriously when I read it was Mike who developed it.
The Osha fact sheet document I have states that no grounding rod is necessary with a generator IF it is bonded neutral AND the receptacles on the generator are directly used.
This made me think that even though I would normally use the rod and connect the grounds between the 2 genies, adding the bonding plug would be a step up on safety - no? OR...... maybe even...as per the Osha doc, no rod necessary when using the bonding plug???


"Grounding Requirements for Portable and Vehicle-mounted Generators

Under the following conditions, OSHA directs (29 CFR 1926.404(f)(3)(i)) that the frame of a portable generator need not be grounded (connected to earth) and that the frame may serve as the ground (in place of the earth):

The generator supplies only equipment mounted on the generator and/or cordand plug-connected equipment through receptacles mounted on the generator, § 1926.404(f)(3)(i)(A), and
The noncurrent-carrying metal parts of equipment (such as the fuel tank, the internal combustion engine, and the generator’s housing) are bonded to the generator frame, and the equipment grounding conductor terminals (of the power receptacles that are a part of [mounted on] the generator) are bonded to the generator frame, § 1926.404(f)(3)(i)(B).
Thus, rather than connect to a grounding electrode system, such as a driven ground rod, the generator’s frame replaces the grounding electrode.

If these conditions do not exist, then a grounding electrode, such as a ground rod, is required.

If the portable generator is providing electric power to a structure by connection via a transfer switch to a structure (home, office, shop, trailer, or similar) it must be connected to a grounding electrode system, such as a driven ground rod. The transfer switch must be approved for the use and installed in accordance with the manufacturer’s installation instructions by a qualified electrician.

Grounding requirements for generators connected via transfer switches are covered by Article 250 of the National Electrical Code (NEC)."

[frank kayser]

One thing you can do to see if using a neutral-ground bonding plug is safe to use.
To check,  take a measurement between H-G, N-G, H-N.
H-G should read 120v
N-G should read zero.
H-N should read 120.v


If the reading is as above, a neutral-ground bonding plug can be safely used on that genny.
Do this on both gennys.



The Honda I have runs:
H-G should read 60v
N-G should read 60v.
H-N should read 120v
It is not safe to use a neutral-ground bonding plug on this setup.
Most gens are not set this way.


Mostly grounding rods are to dissipate near-strike lightning, as I understand it.
As far as what The Code says, or what the local jurisdiction says is WAY above my pay grade.

[Debbie Dunkley]

One thing you can do to see if using a neutral-ground bonding plug is safe to use.
To check,  take a measurement between H-G, N-G, H-N.
H-G should read 120v
N-G should read zero.
H-N should read 120.v


If the reading is as above, a neutral-ground bonding plug can be safely used on that genny.
Do this on both gennys.



The Honda I have runs:
H-G should read 60v
N-G should read 60v.
H-N should read 120v
It is not safe to use a neutral-ground bonding plug on this setup.
Most gens are not set this way.


Mostly grounding rods are to dissipate near-strike lightning, as I understand it.
As far as what The Code says, or what the local jurisdiction says is WAY above my pay grade.

I will start them up tomorrow and test them just to be sure even though the manufacturer states they are floating neutral models.
I have a receptacle tester I can use which will indicate the wiring status of the units.

[Mike Monte]

I will start them up tomorrow and test them just to be sure even though the manufacturer states they are floating neutral models.
I have a receptacle tester I can use which will indicate the wiring status of the units.

FWIW: I have two Honda eu3000is generators and searched the "floating ground issue" over the winter.
Since my units have always worked well for my rigs/applications I never thought to check their ground status.
After reading much about floating neutrals (there is alot of info, mostly on RV forums, one such: http://www.rvforum.net/SMF_forum/index.php?topic=86203.15;wap) I decided to check using a basic 3-wire receptacle tester.
Sure enough, one of the yellow lights (I can't remember which one) "flickered"....as I understand, indicating a floating N-G
so
I made a N-G bond plug (really easy to do), plugged it in, and no more flickering.
I assembled one of my PA's (using the gen) in the back yard and all worked well...

..mind you, my PA had always worked well using a single gen but last fall I added a second gen (same model) with the parallel wires for a larger gig (originally scheduled for last month [sob]) and wanted more certainty about grounding.

...this raises a question: Is there such a thing as too much grounding??

[Chris Hindle]

...this raises a question: Is there such a thing as too much grounding??

After someone gets bit from not enough grounding, it's a little too late.
Just sayin.
Mo is better. Over the top may be just about right.
Chris.

[Steven Cohen]

Frank,

My takeaway from a discussion a few years back was that a generator with a floating neutral, one can use a ground to neutral bridge plug. Please correct me if I am wrong but I think you are describing a floating neutral with your Honda generator where you measured "H-G should read 60v
N-G should read 60v.
H-N should read 120v"

 I understood (possibly incorrectly) that if one measures H-G should read 120v, N-G should read zero, and H-N should read 120.v then the generator has a bonded neutral and a ground to neutral bridge plug should not be used. In addition, if a bonded neutral generator is connected to a home's load center, the bonded neutral should be disconnected in the generator.

Here is a link to the discussion,

https://forums.prosoundweb.com/index.php/topic,164927.0.html



 

One thing you can do to see if using a neutral-ground bonding plug is safe to use.
To check,  take a measurement between H-G, N-G, H-N.
H-G should read 120v
N-G should read zero.
H-N should read 120.v


If the reading is as above, a neutral-ground bonding plug can be safely used on that genny.
Do this on both gennys.



The Honda I have runs:
H-G should read 60v
N-G should read 60v.
H-N should read 120v
It is not safe to use a neutral-ground bonding plug on this setup.
Most gens are not set this way.


Mostly grounding rods are to dissipate near-strike lightning, as I understand it.
As far as what The Code says, or what the local jurisdiction says is WAY above my pay grade.

[Debbie Dunkley]

I made a plug yesterday and will check the gennys today using my receptacle tester. If they show floating N - which I am convinced they will - then I will try the plug and make sure all works well.
reply #1 in the PSW thread Steven references would indicate that it is in fact a BAD idea to connect a generator with floating neutral like the Yamaha EF3000 (in a standalone fashion) to a ground rod - I did read that it is UNNECESSARY.

[Debbie Dunkley]

Just tried both generators (actually all 3 - I have 2 of the EF2000 also which can be in parallel).... tester showed 'open ground' on all 3 generators which is exactly what I expected.  I then plugged in my bonding plug and the tester showed 'correct'. I believe it works and as long as I connect the grounds to the gennys as I always do, then I assume I only need the one bonding plug.

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