Advice on wood shop motors in off grid setting

[066logger]

Victron system could do it but the ROI might be awhile
Found this video a while back, awesome system.

Ahahahaha oh I’m sure the wife would be thrilled with half the house filled with solar equipment not to mention the million plus I’d have to spend lol. Geez that’s a sweet setup though!

 

[NC_hydro]

Yeah? 3phase is something I have 0 experience with lol. It runs right overhead my shop in town but my experience has been getting a transformer and pole set to go 3 phase and the included electric bill (shop is currently not hooked to the grid at all) are astronomically expensive $10-20,000. The dual victrons would be sweet! How big of a motor do you think you can run on 20kw? Just for my figuring

16kw continuous and 40kw surge should handle quite a lot

 

[Mattb4]

I’ve definitely looked into them, the worst part is I’m not sure the negatives outweigh the positives in my use case. First off another engine to maintain (battery, coolant, oil, keeping stupid mice out etc) and in the used market I’m looking at $5,000+ for a machine that’s got 5-15,000 hours on it. Vs my tractor only has 300 hours, it’s a 46hp (engine hp, 38pto hp) kubota non turbo diesel that gets used regularly enough here on the farm that the battery doesn’t go dead but in a decade I’ve only put 300 hours on it. The pto generators are cheap here ($1,250.00 for 35kw generac) and they have a much smaller footprint than a similarly sized engine drive generator since I’ve gotta store my tractor regardless…

Just about everyone that I know of that tries a PTO generator ends up not liking it. They get in the way of your tractor being a tractor and are not particularly good at outputting a stable voltage and frequency. Did not look at prices but this site has quite a few used diesels gensets: https://www.generatorsource.com/Used-Generators

 

[Hedges]

Yeah? 3phase is something I have 0 experience with lol. It runs right overhead my shop in town but my experience has been getting a transformer and pole set to go 3 phase and the included electric bill (shop is currently not hooked to the grid at all) are astronomically expensive $10-20,000.

Only $10 ~ $20k, huh?

Cost for utility transformer installation?

What has the utility company charged you for a transformer installation or upgrade on their side of the meter? How flexible/negotiable were they? I have a house in Oakland, CA. with 100A service. To support the PV install I want to do, and for more loads like electric heat (presently all gas)...

diysolarforum.com

The dual victrons would be sweet! How big of a motor do you think you can run on 20kw? Just for my figuring

Also look at Rosie and Sunny Island.

16kw continuous and 40kw surge should handle quite a lot

I have 23kW continuous, 44kW surge for my main system.
The 3-phase one would be 18kW continuous, 33kW surge. It takes in single-phase 120V from grid and makes 3-phase.

Would like to see a rotating mass to provide surge.
There are rotary phase converters to make 3-phase - wonder how they do for that?

 

[Hedges]

If total wattage is within inverter limit, only starting is a problem, consider a 3-phase motor and VFD. It ramps up RPM slowly.
Ideally PF corrected VFD.

I think there are some choices for 5 HP VFD that works with 120/240V split-phase rather than 3-phase input. The off brands are more likely to claim split-phase input. Probably any do work, but can't deliver as much power.

VFD are pretty inexpensive. Much less than an inverter.
3-phase motors tend to be more expensive but can find used on eBay.

 

[066logger]

16kw continuous and 40kw surge should handle quite a lot

I would think so haha. I was surprised one 5hp motor can draw over 100amps on startup .

 

[fmeili1]

I would think so haha. I was surprised one 5hp motor can draw over 100amps on startup .

My Trane 5 Ton central AC unit (5 hp motor) had an inrush of 162 Amps (measured it twice!), even the label showing "only" 144 LRA. After installing a "Micro-Air EasyStart 368 Soft Starter" it reduced the inrush to 33.5 Amps! Now my inverters have no problem at all with it.

 

[066logger]

Only $10 ~ $20k, huh?

Cost for utility transformer installation?

What has the utility company charged you for a transformer installation or upgrade on their side of the meter? How flexible/negotiable were they? I have a house in Oakland, CA. with 100A service. To support the PV install I want to do, and for more loads like electric heat (presently all gas)...

diysolarforum.com

Also look at Rosie and Sunny Island.



I have 23kW continuous, 44kW surge for my main system.
The 3-phase one would be 18kW continuous, 33kW surge. It takes in single-phase 120V from grid and makes 3-phase.

Would like to see a rotating mass to provide surge.
There are rotary phase converters to make 3-phase - wonder how they do for that?

Oh good grief!! $150,000!!! That’s insanity. I was talking to one of the local business owners here who has a small engine shop and was adding on another building and looking at adding an additional 400 amp service. I assumed 3 phase as he’s in the middle of the industrial part of town but he was complaining they had quoted him a little over $10,000 to set the pole and put in a meter base. Maybe it was just single phase . Good grief. Yeah I’m never connecting to the grid… no wonder the local sawmill down the road runs a Detroit two stroke diesel generator with 20’ tall straight pipes when the 3 phase lines run right over his log yard! I can hear that engine bog down every time his log carriage rolls through and he’s about 4 miles away as the crow flies .

 

[066logger]

My Trane 5 Ton central AC unit (5 hp motor) had an inrush of 162 Amps (measured it twice!), even the label showing "only" 144 LRA. After installing a "Micro-Air EasyStart 368 Soft Starter" it reduced the inrush to 33.5 Amps! Now my inverters have no problem at all with it.

That’s definitely a good thing to keep in mind! I’ll look into it. If nothing else it might help the inrush current more manageable for the tractor. I posted on a tractor sub over on Reddit looking for people with experience doing what I’m looking to do and one member had done basically the same thing with not great results. I guess the governor on his particular tractor he was using was struggling to keep the motor where it needed to be and he had all sorts of problems with over voltage and brownouts, blowing up his electric motors and switches. I’m still waiting on the details on that one…

 

[066logger]

Just about everyone that I know of that tries a PTO generator ends up not liking it. They get in the way of your tractor being a tractor and are not particularly good at outputting a stable voltage and frequency. Did not look at prices but this site has quite a few used diesels gensets: https://www.generatorsource.com/Used-Generators

Yeah . I’ve definitely heard some mixed opinions on them… some seem to really get along good with them but some absolutely hate them. I do have a quick attach and hydraulic top link on my 3 point so it’s only a 5-10 minute operation to swap implements, inevitably the implement I need is never on it anyway so I’m always swapping back and forth lol.

 

[066logger]

If total wattage is within inverter limit, only starting is a problem, consider a 3-phase motor and VFD. It ramps up RPM slowly.
Ideally PF corrected VFD.

I think there are some choices for 5 HP VFD that works with 120/240V split-phase rather than 3-phase input. The off brands are more likely to claim split-phase input. Probably any do work, but can't deliver as much power.

VFD are pretty inexpensive. Much less than an inverter.
3-phase motors tend to be more expensive but can find used on eBay.

I think I’m probably pretty far over the limits of what my system is capable of unfortunately. My bigger inverter is only a 6,000 watt 18,000 watt surge (supposedly).