Portable Generator Grounding

[marspec]

I have purchased a pair of Honda 2000s and will parallel them. My fiver has a hard wired Progressive. I know I need to provide a ground by connecting a plug to the generators with the neutral and ground connected. The question is: Make up a plug for one generator or both?

[Bobbo]

You are quite welcome. However, you owe me a cold one if we ever park next to each other. :B

[marspec]

Ah Ha! Yes I took the plug from one gen and xferred it to the other.
Live and learn. Thanks.

[Bobbo]

marspec wrote:

Bobbo wrote:

marspec wrote:
When the generators were paralleled the EMS allowed hook-up and ran the AC. There was, however, an open ground message. HMMM!

This is puzzling. If there was an open ground, the EMS should not have allowed the hook-up. If there was no open ground, there should have been no open ground message.

Are you sure the open ground message wasn't a message from an earlier error? The EMS does keep displaying the error message from earlier even after the problem is corrected.

I would agree re prior error message except when a single gen was hooked up the error didn't appear. When paralleled the EMS displayed Line 1 voltage, Line 1 amps, Line 2 voltage, Line 2 amps, 60 cycles, E0, and then whatever the msg for open ground is EF2??

I think I got your answer.

There is no "EF2."

There is "E2" which means that there is an open ground and it will not connect.

There is also a "PE2" which means that there was a previous open ground error, but it has been corrected.

It should work like this, you plug the bonding plug into the generator and crank it, you get E0 and power, but no PE message.

You unplug the bonding plug, you get E2 (open ground) and no power.

You plug the bonding plug back in, you get E0 and power, followed by PE2 which means you previously had an open ground, but it is now repaired.

Apparently, at some point, you had removed the bonding plug while the EMS was monitoring the line, and the EMS detected it.

[marspec]

Bobbo wrote:

marspec wrote:
When the generators were paralleled the EMS allowed hook-up and ran the AC. There was, however, an open ground message. HMMM!

This is puzzling. If there was an open ground, the EMS should not have allowed the hook-up. If there was no open ground, there should have been no open ground message.

Are you sure the open ground message wasn't a message from an earlier error? The EMS does keep displaying the error message from earlier even after the problem is corrected.

I would agree re prior error message except when a single gen was hooked up the error didn't appear. When paralleled the EMS displayed Line 1 voltage, Line 1 amps, Line 2 voltage, Line 2 amps, 60 cycles, E0, and then whatever the msg for open ground is EF2??

[Bobbo]

marspec wrote:
When the generators were paralleled the EMS allowed hook-up and ran the AC. There was, however, an open ground message. HMMM!

This is puzzling. If there was an open ground, the EMS should not have allowed the hook-up. If there was no open ground, there should have been no open ground message.

Are you sure the open ground message wasn't a message from an earlier error? The EMS does keep displaying the error message from earlier even after the problem is corrected.

[marspec]

Well I made a new plug without the resistor. (And yes I installed the plug on the generator.) When a single generator was hooked to the RV the EMS allowed hook-up with no errors. When the generators were paralleled the EMS allowed hook-up and ran the AC. There was, however, an open ground message. HMMM! FWIW I was amazed to find out the installed vacuum pulled 10 amps.

[time2roll]

Here are a couple pics of how it is done for an electric vehicle:
Note it has two resistors as this also applies to 240v EV charging.
For an RV it would just be one resistor neutral/ground or the EMS will detect reverse polarity (I tried that also).

I suppose it depends on the type of grounding plug you use but this is how I did it: (just like mine)






Got the resistors from Radio Shack and the plug from Home Depot

[time2roll]

Yes, plugged into my Kipor portable generator. The PI EMS would switch on/off/on real time as I plugged in, removed, and plugged in my bonding plug with a resistor.

Use some copper in place of the resistor to make it work.

[Bobbo]

A picture is at the bottom of this page of a thread from October 2012.

marspec wrote:

smkettner wrote:
For additional safety you can make the bond plug with a 100,000 ohm 1/2 watt resistor.

OK I wired a plug with the resistor and hooked a single generator to the fiver and got the no ground message. I doubt that using only a single gen should make a difference. I had a 98K reading between the ground and neutral plug. I've wired another plug without the resistor and will give that a try tomorrow. The generator was putting out 129V at 60 cycles. What voltage reading are others getting?

This may be a dumb question, but I've got to ask it: You did put the plug into a socket ON THE GENERATOR didn't you? Plugging it in inside the RV won't do anything.

[eric1514]

Somebody post a picture of this plug...please.

[time2roll]

I am at a loss on why yours does not work. The resistor should pass enough to spoof the bond but provide high resistance to limit any fault current to a safe level. This method was suggested for charging an electric vehicle from a generator where the cord has a similar ground continuity check. It worked. Just for fun I tried it with my 30a hardwired PI EMS and it also worked.

[marspec]

smkettner wrote:
For additional safety you can make the bond plug with a 100,000 ohm 1/2 watt resistor.

OK I wired a plug with the resistor and hooked a single generator to the fiver and got the no ground message. I doubt that using only a single gen should make a difference. I had a 98K reading between the ground and neutral plug. I've wired another plug without the resistor and will give that a try tomorrow. The generator was putting out 129V at 60 cycles. What voltage reading are others getting?

[Bobbo]

wa8yxm wrote:
Or use the bypass.. Question.. Will the bypass reset when power is removed (I believe it will)

No, it doesn't reset itself. It is a slide switch that has to be slid back to its normal position. Once, I was testing my system, and slid the switch to bypass. It was 6 months before I noticed it was bypassed and not properly protecting my coach.

[wa8yxm]

If possible I'd modify the 30 amp outlet on the parallel cables..

Or use the bypass.. Question.. Will the bypass reset when power is removed (I believe it will)

The Power Gard (Surge guard) monitors frequency and voltage, So do the Honda inverter generators. if the frequency goes wonkey they tend to catch fire. thus they lock to each other and to the crystal controlled time base, They are, more "Paranoid" of frequency errors than your surge guard and for very good reason.

Likewise if the voltage drops it tends to drop all the way to ZERO, (or if it climbs) NOTE this is not true of some of the china knockoffs.. But it is for Honda (And, though not as well ONAN RV generators), they perform all the functions of the Surge Guard and do it well.

Most other brands I do not know about (I know one Chinese brand that had over voltage issues.. but I'll not name it).

Now: here is a question for folks: WHY do we use a safety ground (And yes, I know the answer).