Portable Generators

[OldGuyNewJeep]

Here in CT we got walloped by tropical storm Isaias on Tuesday. Many are still without power. Mine came back late last night.

Anyway, I have a generator inlet and interlock kit installed. It’s fantastically easy and a real life saver. My generator is a bit underpowered for my needs, though, and also 30 years old. I want to upgrade.

Criteria: the 30a twist lock connection *must* be floating neutral. I do not want the headache or expense of a transfer switch. That’s too bad, too, because this looks like a hell of a nice unit for the price.

I’m looking to keep the budget at around $1k. Don’t get me wrong, I want one of these, but I can’t justify that price for something that will get used once in a blue moon.

Recommendations?

The Harbor Freight Predator 9000 is very seriously tempting me. For the price, it may just be worth gambling. I intend to keep my 30 year old workhorse as a backup because it’s never let me down.

Oh, I want at least 7000 running watts.

The trouble I’m having is that no one advertises if their unit is floating neutral or bonded neutral. I’ve grown weary of downloading manuals to check, and I figure one of you guys can offer an endorsement. Thanks!

Edit: I got the Generac. The Predator is also bonded neutral. I think they all are these days. Manually disconnecting the bond is easy and that’s what I’ll do when hooking up to the inlet.

Sponsored

 

[Jdsmoke]

The Genacs are great. Doesn’t the transfer switch stop the electricity from back flowing down the line. I thought it’s goal was disconnecting from the power grid to protect workers.

 

[OldGuyNewJeep]

The Genacs are great. Doesn’t the transfer switch stop the electricity from back flowing down the line. I thought it’s goal was disconnecting from the power grid to protect workers.

I have an interlock installed in my panel. It's basically just a piece of sheet metal that prevents you from turning on the generator circuit without first turning of the main. It's exactly for the purpose you say - to prevent energizing the grid with a generator. Where I live, it is required per code. (Plugging in to, say, a dryer outlet is a no-no.)

What I love about an interlock setup is that the generator powers the whole panel. It's up to me to decide which circuits I want to enable/disable. For example, I turn off the Central A/C circuit because my generator can't power my 3 ton system. Likewise for my dryer and electric stove circuits. (Turning them off is just to prevent someone in my household from accidentally turning on a high-draw appliance and overloading the generator.)

Now, if you have a bonded-neutral generator with full GFCI protected outlets like the one at Costco that I linked above, you'll need to get a GFI transfer switch. Transfer switches work great, but you have to plan ahead and decide which circuits you'll want. Changing your mind, later, is another check written to your electrician... plus, their initial cost is much higher.

Soooo... what I'm looking for is someone who can say "I have XYZ connected to my interlock and I love it!" (Maybe I'm just looking for someone to tell me that getting a Harbor Freight generator isn't the dumbest thing they've ever heard.)

 

[OldGuyNewJeep]

Updating my own post in case it someday helps someone...

So, this thread asks and answers my same question. It’s an interesting discussion on a fairly important topic, albeit one that few seem to know about. After reading that thread and consulting a few other resources (including a retired electrician), I decided that the Generac XT8500EFI would probably be “safe enough” to plug-in to my inlet as-is, but I will disconnect the bond because I don’t like to take chances.

Yes, the Generac (and most modern portable generators) have bonded neutral GFCI 120v receptacles.

Some manufacturers (Champion) document how to convert their generators to floating neutral, but doing so makes them non-compliant with OSHA/NEC when used as a portable (i.e. plugging tools into the outlets) So, you are supposed to put a sign/warning label in place when/if you disconnect the bond.

I will be leaving my new Generac in its factory configuration for storage and portable use, but will disconnect the bond when tying it to my house wiring.

In case the forum link above ever expires, I’m pasting what I believe to be the best reply from that thread:

Any portable generator that has receptacles is under 10kw, sits on the ground, and is intended by design to be a separately derived system for the operation of cord and plug tools and equipment. The NEC requires any seperately derived system to have a main bonding means between neutral and ground.

Operating a portable generator as emergency power for single family dwellings has been a dilemma for manufacturers for years as the neutral to ground bond cannot exist at the generator when connected to premise wiring which also has a main bonding jumper with the utility. One or the other but not both. They have just recently been writing in their instructions on emergency power use about this issue of neutral and ground bonding.

Limit your exposure to the generator when operating the house wiring through your integrated interlock system. Stop it, fuel it, start it, get away from it. I don't mean that as there is eminent danger; the possibility of electrical shock is there but it has to have nearly powerball win odds to happen.

Do not drive a ground rod and attach to the frame, this increases the odds of getting shocked. Do not operate hand tools from the generator receptacles just let the generator power the premise wiring.

To date I do not know of any manufacturer of a portable generator where in their instructions actually tells you what to do about the neutral and ground bonding. They just say contact a licensed electrician about it. By doing so they pass the liability to you and the electrician.

The manufacturers never meant for you to power your house with a portable, but it was one heck of a selling point to say you could.

Anyway, there you have it.

 

[Blade1668]

OldGuyNewJeep
Thanks for that info and linking in your other post..... as no surprise to me; I have learned that I know even less, especially on wiring and glad to have a good buddy that's a "retired" Electrician too.

 

[OldGuyNewJeep]

OldGuyNewJeep
Thanks for that info and linking in your other post..... as no surprise to me; I have learned that I know even less, especially on wiring and glad to have a good buddy that's a "retired" Electrician too.

You bet. It’s quite a deep rabbit hole. (BTW, that link isn’t to a post that I made, but the guy who made it had my same question.)

Today I watched all 27 minutes of this, and came away with a MUCH better understanding of the issue. I highly recommend watching.



I also read all the comments on that video... while the guy who made it had the same conclusion as in the forum post (ie nothing bad is likely to happen plugging a bonded generator into house wiring), some of the commentators vehemently disagreed. Essentially, you end up with current running through the ground wire in the cord between the generator and the inlet. If it were compromised (cut it with lawnmower?), or if you were to touch the inlet box and the generator frame at the same time, you could have a bad time. Very unlikely, but NEC writes code to cover all possible scenarios.

I’m going to evaluate how hard it is to toggle my new Generac from bonded to floating. If it’s just a jumper like in that video, I’ll probably do it when plugging in to the house, then putting it back when done. After my warranty expires I will install a toggle switch to accomplish switching. If it isn’t easy, I’ll probably look into a neutral switching transfer switch. (But I’d use it as-is in an emergency, as the risk is low enough for me to tolerate.)

Edit: disconnecting the bond is easy, and that’s what I’ll do.

Man, the things they don’t tell you when buying these things can kill you! Yeah, CO is the obvious one, but getting shocked is not high on my todo list, either.

Glad someone else is interested in this topic.

 

[Blade1668]

Well watching that video made it clear as mud. Some of what was being explained in video I have "seen and felt" with 10 and 20 k gen sets in military. Due to grounding, ground rods wiring and rain. Walking near the areas "you could feel the ground vibration" from electric transmission though the ground.... not just the generator running. I missed the part of it that you got from someone else posting, but good for it.

Sponsored