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Small Cabin Forum / Off-Grid Living / Need Generator to Panel Wiring Opinions/Advice
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SCSJeff
Member
# Posted: 11 Oct 2017 22:25
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Hi all,

This is going to be long, so bare with me please

I've been running our off-grid vacation cabin for the last 3 years in the following manner:

Cabin wired AC like a conventional residence. I have a 12 space 240v panel that is fed directly from our Coleman PowerMate 6250W (Surge) 240V Generator. Generator is located behind shed approximately 50 feet away. Feed from genny is 10 Gauge. I also have a small 1500W Champion generator that I've made up a cable that jumps both hots so I can feed both sides of my panel through the same feed.

I have a 240v deep well pump (500'). Hence the need for a 240v panel. There is also a 120v septic pump that has a pretty good amp draw when it is running as well. In addition, I have a 5 cubic foot chest freezer that I'm going to use a Johnson Control on to "convert" it to a fridge. Figure it would run whenever I have the Genny running and that should keep it cold enough for a weekend.

Off one of the circuits in my panel (15A lights & and a few receptacles), I have an auto transfer switch that is also fed by my small solar setup:

Solar Setup consists of a Xantrex ProSine 600W and (2) Golf Cart Batteries. Solar setup also resides in shed and feeds the auto transfer switch with a 12 Gauge wire.

This gives me most of my lights and a few receptacles that are live on solar and then auto switches over to my generator when running.

Here's what I've discovered to be a pain working with this setup over the last 3 years:

1) Both ceiling lights in our 2 upstairs bedrooms and kitchen high hats are not on the "solar" circuit. I do have 1 receptacle in each room that is hot on the solar and I guess at the time, I assumed I would just plug a lamp into the receptacle. But now, I wish those ceiling lights worked without having to start a generator. (or at least our beast. See next point)

2) Coleman Generator is LOUD and obnoxious (not really an issue inside the cabin, but I feel bad for the neighbors/wildlife . But, except for when the well pump is needed, I feel like it is just screaming and sucking down gas for very little use requirements. I do use the Champion a lot too, which is much quieter. But, it struggles handling anything more than just what is on the solar circuit. (And obviously can't run the well pump or the septic pump)

3) Very annoying to have to start generator just to flush the toilet (after pressure tank is exhausted) and/or wash hands, etc. Then just to shut it back off 5 minutes later...

4) Very annoying having to walk out to start/stop generators behind shed. Especially in the dark. Have to be completely on guard for rattlesnakes. Seems they like the hum/vibration of the running generators...

5) Not sure this is all the easiest setup for someone else to understand if they come to the cabin without me?

So I have plans to address these complaints...

1) Too complicated (and expensive) to add more circuits to the solar. Therefore, I want to get an inverter generator that will be much quieter and fuel efficient. (Looking at Champion 3500W Inverter) This will run everything (except well pump) and I won't feel as bad just letting that run for extended periods.

2) Quieter Inverter Generator should address this too.

3) I plan on replacing the existing pressure tank with a 100 Gallon storage tank and a 120v shurflo pump that will run off the solar circuit. This way I can run the big genny once or twice a weekend to just fill the storage tank from the well.

4) Looking at the remote start/stop version of the Champion. How nice to have power first thing in the morning without having to get dressed and go out in the snow/rain, etc.

So finally my concern/question with all this...

They way I am feeding both sides of my panel by jumping the hots inside the cable for the 120v generator... Seems after a bunch of research my findings are as follows:

1) Could be possible to overload the neutral. However, since the 3500W genny that I'm looking at can only max out at around 25A, this "should" not be a concern. Can anyone confirm? If this is a concern, I could get a larger panel and just move all the circuits to one leg. This way I can eliminate the jumper in the cable. But, aren't I still running the same amount of amps over the neutral that way anyway?

2) I normally switch off the breaker for the well pump when running the small genny (just for peace of mind). However, I have forgot once or twice after plugging in the genny and then ran inside to flip it off. I feel like that is a lot to expect someone else to remember if I'm not around. I understand if I wasn't feeding both legs of the panel, this would not be a concern... the pump would just not start. However, I'm reading mixed opinions on what would happen with how I'm feeding 120v (same phase) to both sides of the panel. Some say it would cancel out and no voltage at all would be seen by the pump. But, I don't know. It would be great if I didn't have to worry about whether the pump breakers were off or not.

3) Is the 10 Gauge cable at ~50' run from behind the shed to the panel OK when feeding 120v over it (don't expect to ever hit the generator max of 25 amps, but would prefer to be safe). I tested the voltage drop with a small load going on and I was getting a solid 120v in the house. So that seems OK. I'm just concerned about over heating the feed if suddenly the freezer and the septic kick on at the same time all the lights, tv, etc. are on while running the vacuum... (You know, the perfect storm)

Thanks for reading through this everyone! I know it was long, but I wanted to try to give as much info as possible in advance.

Thanks,

Jeff

bldginsp
Member
# Posted: 17 Oct 2017 09:09
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Make sure ground and neutral are always bonded at the source to clear ground fault

toyota_mdt_tech
Member
# Posted: 17 Oct 2017 22:06 - Edited by: toyota_mdt_tech
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Get the new Honda EU7000is. Its quiet, it has electric start, its set up for remote start (do it from cabin)
Now under full load, this is a whisper quiet 60db, in eco mode, its 52db. I have the slightly older version, the EU6500is, its a carb engine, the 7000 is EFI.

With a 240V, you can run both legs of your panel. I know this generator has a floating ground. The ground only works if you hook it to a ground rod. There is not actual neutral, the stator wiring has a "WYE" point, but its not tapped and wouldn't work if it was, it would he half the voltage.

The duplex 20 amp outlet is GFCI protected, so no shock, but didnt see the GFCI rating on the 240V set up.

I have my EU6500is wiring into my house, its so quiet, no one knows it there. It runs my electric hot water tank, electric dryer, electric range and does them all in "eco" mode. It is as quiet as a little Honda EU2000i

Its not low cost like your champions, but you will throw rocks at those champions after owning the EU7000is. You can get it now for about $3799.
http://www.electricgeneratordepot.com/honda-7000watt-super-quiet-light-weight-inverte r-120-240v-fuel-efficient-generator-eu7000is

I paid cash for mine from a Honda dealer in Montana and got it for $3125, included shipping and no tax.

SCSJeff
Member
# Posted: 18 Oct 2017 08:42
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bldginsp, So you're saying that if I bond neutral and ground at the genny and then remove the bond at the panel, my GFCI receptacles should test correctly using a tester?

toyota, Indeed, when we first built the cabin, my intention was to get the big Honda. (We have a 6500 at work and it is super quiet) However, as the cabin construction progressed, that much outlay of cash became harder and harder to justify to the finance committee I'm also very concerned about theft. Another reason I started looking at the cheaper generators. (It won't hurt as bad if/when they get stolen)

In addition, I was just up last weekend and did some tests with my Kill A Watt. Under no load and/or light load, the Coleman 6250 (surge) was giving a nice 120v inside the cabin. However, when the well pump was running, the voltage dropped all the way down to 106v :-o. This has me concerned that I need yet a bigger genny just for the well. Also makes me wonder if the Honda (5500 rated is the same as my coleman) would even be large enough to handle the well (certainly not while on eco-mode, which would be a major reason for using the Honda in the first place)

I'm actually now debating pulling the well circuit out of the panel and dedicating it to just a 240v genny input. I'll keep this input right outside the cabin and keep the Coleman right outside too. This way I can step out the door to start/stop it under plenty of light at night (to see rattlesnakes). this will also cut about 50' out of the run too.

toyota_mdt_tech
Member
# Posted: 18 Oct 2017 21:27 - Edited by: toyota_mdt_tech
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Quoting: SCSJeff
bldginsp, So you're saying that if I bond neutral and ground at the genny and then remove the bond at the panel, my GFCI receptacles should test correctly using a tester?


Well, the neutral doesnt exist, you have line 1 and line 2, across them, you have your voltage. Ground is open/floating/hooked to gennie chassis. If you ground the gennie chassis to a ground rod, it has an earth ground. If you bond a neutral (in this case, one leg of the AC circuit) and ground together, are you hooking a live wire to the generator chassis?

Just a question.

SCSJeff
Member
# Posted: 19 Oct 2017 08:23
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Quoting: toyota_mdt_tech
Well, the neutral doesnt exist, you have line 1 and line 2, across them, you have your voltage.


Are you referring to the GFCI receptacles or the generator?

Quoting: toyota_mdt_tech
are you hooking a live wire to the generator chassis?


Not sure what you mean? (IE: sarcasm or genuine question?)

toyota_mdt_tech
Member
# Posted: 19 Oct 2017 08:49 - Edited by: toyota_mdt_tech
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There is a few models with GFCI, I think the EU7000is and the EB2000i (not EU) but that is only for the 110V stuff. The 220 on the 7000 doesnt mention it, so I assume its not.

I was serious on the bonded neutral. The neutral is just one half of the line voltage. Its looking for the other half, really no neutral on a generator. There is some generators that have a neutral, but its commercial, super spendy etc. My EU2000i is all plastic, well, anything I can touch is plastic, so its insulated in that regards.

My question would be if you bonded what you thing is the neutral to chassis, you would be hooking one have of your voltage leg to the generator chassis. I havent tested this, but it seems that is what you'd be doing. I dont know how the GFCI's in the generators work without the neutral, special ones? Not sure, but those would certainly prevent any shock hazard.

SCSJeff
Member
# Posted: 19 Oct 2017 10:08
Reply 


Ah, OK, Got it

That would explain why most of the "cheap" generators I've used have no neutral/ground bound. (They don't have a neutral .

I know my brother-in-law has a larger Honda commercial generator that when he tried backfeeding his house during a power outage, it kept blowing the breaker. I think he ended up having an electrician remove the neutral/ground bound in the generator to address that.

So, I take it my GFCI's will never test correctly with a tester as long as I'm feeding the panel with a generator?

So, as a side note to another thread I have open. Should I ground the generator to my ground rod if my panel is already grounded?

Thanks,

Jeff

toyota_mdt_tech
Member
# Posted: 19 Oct 2017 10:48
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Quoting: SCSJeff
So, as a side note to another thread I have open. Should I ground the generator to my ground rod if my panel is already grounded? Thanks,Jeff
I would say that is the way it was designed, you should have a lug on the generator itself just for that. Now feeding a panel, and one that is bonded, not sure if that will be an issue. Basically, that is bonding the earth ground to the one leg of the feed still. Its tricky when you have no actual neutral.

SCSJeff
Member
# Posted: 19 Oct 2017 10:55
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Quoting: toyota_mdt_tech
Now feeding a panel, and one that is bonded, not sure if that will be an issue.


Yeah, that's what I'm finding... No clear consensus from people (smarter than I on the subject) on all the forums and/or from electricians that I've spoke to...

I guess once I decide on a final setup, I'll go ahead and ground the generator (if it is designed for that), Although, doesn't seem to matter much one way or the other as long a common sense is used in every other part of the system...

Thanks for all your input toyota!

toyota_mdt_tech
Member
# Posted: 19 Oct 2017 21:23 - Edited by: toyota_mdt_tech
Reply 


Jeff, hooking the generator to ground is fine if your just running cords from the generator, but if you hook it into a panel, I think removing the neutral and ground buss bars bond inside the panel would be a good idea. In other words, wire it like its not the primary panel, but a sub panel (bond removed) and if it ever becomes the primary, bond it. I would just buy the extra ground BUSS bar for your panel (you can buy them right where you get the panel from and there is mounts inside the panel) and wire them separately, ie bare grounds to the added buss, white wires or neutrals (not a true neutral, but you know what I mean) to the existing BUSS and if it ever becomes a primary panel (hooked up to the grid) then just run a jumper wire to tie the 2 bars together. Then you can use the ground rod hooked to the generator chassis which would be tied into the ground bar in the panel. Then your system would have an earth ground.

SCSJeff
Member
# Posted: 19 Oct 2017 21:59
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Awesome advice toyota!

Thank You!

neckless
Member
# Posted: 24 Oct 2017 09:15
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the pump is the biggest pain for you cause your using water all the time,,,,wonder if u filled a tank from well then use a 12 volt pump to service the pressure tank....could go a week on a fill or more and no need for the 240 very often

SCSJeff
Member
# Posted: 24 Oct 2017 14:18
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neckless,

I know it probably got lost in my long post to start this thread. But, that is exactly what I'm planning on doing! I can only fit between a 100 - 130 gallon tank inside, so I don't know about going a whole week (maybe if I was by myself). But, yeah, if I can get by with only needing the big genny once per trip (or at worse, once per day), that would simplify a lot and save fuel)

neckless
Member
# Posted: 25 Oct 2017 05:02
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some times u just got to redneck it lol

toyota_mdt_tech
Member
# Posted: 25 Oct 2017 10:36
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How about an elevated storage container, lets say 500 gallons and just use the existing head pressure. Is you cabin downhill from well, store water close to well in elevate position. Run pump to fill storage and good for a while.

SCSJeff
Member
# Posted: 25 Oct 2017 15:30
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Unfortunately, I use the cabin through the winter and would have freezing temperatures to deal with. (And no, I'm not downhill from the well) I don't really want the expense or the logistics of putting in an in ground cistern. So I'm limited to what I can fit inside the cabin. I think 100-150 gallons would get a group of 4-8 guys through a day of showers and flushing. So I'm fine with running the generator for 15 minutes a day to refill the storage tank. I can work that around my convenience.

bldginsp
Member
# Posted: 6 Nov 2017 08:53
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Quoting: SCSJeff
bldginsp, So you're saying that if I bond neutral and ground at the genny and then remove the bond at the panel, my GFCI receptacles should test correctly using a tester?

Please, hire an electrician.

PA_Bound
Member
# Posted: 6 Nov 2017 10:54 - Edited by: PA_Bound
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Quoting: shelleyWalern
Oh, and the "trick" with connecting the generator to the dryer outlet to backfeed the house? DON'T YOU DARE!! It will result in damage and/or injury...


@shellyWalern... I'm curious, do you have facts or details to support the risks and possible damage if you back-feed a panel from something like a dryer connection? I've never done this myself and don't necessarily plan to... but I have a friend who worked in industrial health and safety who did this on several occasions- all without issue. I will add however, he did first make sure to flip the breakers disconnecting the entire house from the grid.

Additional detail would be valuable here, instead of just a blanket 'don't do it' statement.

SCSJeff
Member
# Posted: 6 Nov 2017 12:24
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Quoting: bldginsp
Please, hire an electrician.



Quoting: SCSJeff
Yeah, that's what I'm finding... No clear consensus from people (smarter than I on the subject) on all the forums and/or from electricians that I've spoke to...


As maybe could be inferred... I did hire an electrician to do the initial install. He was not sure why the GFCI receptacles did not test correctly. I work with an electrician and he said they will never test correctly when being fed by a portable generator. I spoke with a 3rd electrician and he also was scratching his head about it.

So you see why I'm now asking on this forum?

idk: If I can't get a consensus from professionals, Maybe I'm overthinking this and should just not care

MntGoat
Member
# Posted: 6 Nov 2017 12:59
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Quoting: shelleyWalern
Oh, and the "trick" with connecting the generator to the dryer outlet to backfeed the house? DON'T YOU DARE!! It will result in damage and/or injury...


Ignore this statement, clearly no idea.

toyota_mdt_tech
Member
# Posted: 6 Nov 2017 19:13 - Edited by: toyota_mdt_tech
Reply 


I am certain Mt Goats comment was tongue in cheek. You can always wire in a true "inlet" vs outlet, grab you a panel interlock for just that circuit alone, this will prevent it and the main breaker from ever being on at the same time.

Home Depot sells them:
https://www.homedepot.com/p/Square-D-Homeline-Outdoor-Generator-Inter-Lock-Kit-HOMRBG K2C/203030954

I would still inquire if this meet the code for your area.

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