12kw Isuzu Diesel Generator

[Greenhorn18]

Hey there how you doin today? I'm looking to power an off grid cabin that's solely powered off a Isuzu 12kw diesel generator. Specifically the one that Central Maine Diesel carries. I have a few questions:

Can I wire the generator into its own 100 amp circuit panel where I could then set specific 120v to 240v breakers to outlets? How would I go about doing this?

Can I somehow wire the Isuzu into a backup generator so that the backup automatically comes on if the Isuzu shuts down such as for maintenance?

Last, goes along with the first question but could I run a mini split through that 100amp breaker system?

Thank you very much if you can answer any or all of these for me, much appreciated! Enjoy life

 

[techman]

The generator is a 120/240V so yes you can feed a regular panel. 12 KW is enough power to run a mini-split and other loads. Just watch for big loads like hot water heaters, electric ovens, etc. You need enough reserve to start the compressor, and if the gen is heavily loaded it may not start the compressor.

As for wiring the the generator to a panel, if you not sure about that, see an electrician about it. It is standard wiring technology which you would have from regular utility power.

For the backup you mention, I assume a second generator. You will need an appropriately sized transfer switch to be able to switch between two sources as you have described.

paul

 

[Greenhorn18]

Thank you Paul! So say I'm pulling something like 4500 watts continuously, the generator would still be able to start the compressor yeah? Wiring the generator doesn't seem out of my capabilities, a bit more research and videos and I'll be confident.

You assumed correctly, I'd have a much less expensive 12kw gas powered generator to transfer the load so that I could change oil, filters etc. on the Isuzu. I assume a 100amp transfer switch to the second would work just fine?

So my plan would be to wire the Isuzu into a panel that I could then distribute the amps where I'd want. Add a transfer switch from the cheap gas gen to the panel to switchover for maintenance. All off the grid!

I figured the Isuzu is the best choice for continuous use 365 because that's what it was designed for. I hope the over 30k hours continuous use is no hoax!

 

[RNeumann]

Lots of good info so far. When sizing remember panels and transfer switches are in amps at 240v and gens will give you watts. Some gens will list amps but most list amps at 120v.

A gen designed for USA 240v split phase (2 120v Lines in opposing phases) will work with about and "normal" panel designed for residential/light commercial.

A mini split could be a 100 different things. You will need to find the specs and make sure you are understanding what the specs say with relation to my first paragraph. The start amps is the killer for gens. It can more than double the running amps so make sure to base your calcs on that figure.

4500watts continuous is a huge continuous load! Wow!!! I've rarely seen a large house that that requires that. I'm hoping those calcs are off. If not I'd strongly recommend an evaluation of your needs and or desire to be off the grid. An off the grid place, or an efficient home can function on about 500w continuous. Most off the grid folks have propane appliances- including the frig which could easily drive that figure down to 100-200 watts.

As mentioned an auto transfer switch could automatically switch from one power source to another. ASCO is one of the more common and major names. You will need to understand the specs and probably call them to figure what causes it to switch. Even the best gens will fluctuate with load etc and you don't want a bunch of false trips/switches between gens.

Good luck!

 

[Greenhorn18]

Lots of good info so far. When sizing remember panels and transfer switches are in amps at 240v and gens will give you watts. Some gens will list amps but most list amps at 120v.

A gen designed for USA 240v split phase (2 120v Lines in opposing phases) will work with about and "normal" panel designed for residential/light commercial.

A mini split could be a 100 different things. You will need to find the specs and make sure you are understanding what the specs say with relation to my first paragraph. The start amps is the killer for gens. It can more than double the running amps so make sure to base your calcs on that figure.

4500watts continuous is a huge continuous load! Wow!!! I've rarely seen a large house that that requires that. I'm hoping those calcs are off. If not I'd strongly recommend an evaluation of your needs and or desire to be off the grid. An off the grid place, or an efficient home can function on about 500w continuous. Most off the grid folks have propane appliances- including the frig which could easily drive that figure down to 100-200 watts.

As mentioned an auto transfer switch could automatically switch from one power source to another. ASCO is one of the more common and major names. You will need to understand the specs and probably call them to figure what causes it to switch. Even the best gens will fluctuate with load etc and you don't want a bunch of false trips/switches between gens.

Good luck!

Yeah it is a huge load - I'm a website software designer by trade so I have multiple computers running at any given time. I worked out the number and its actually cheaper (after the initial purchase) to run an efficient diesel gen over getting power from the grid (not to mention the work required for that to be a possibility!) When I think about it more and more as I always am, maybe its the smarter route to simply get the Isuzu and not a stand by gen, power off the Isuzu for ten or so minutes at welcoming times to do maintenance. I figure if I keep up with all the required maintenance it will last me years to come as it's rated to run 24 hours a day 365. Claiming over 30k hours of use is very attractive to my mind. It's possible to wire a gen to a normal panel being a handy man I figure. What do you think?

 

[Sawyer Rob]

30,000 hrs is a LONG ways from 10 years!

For 10 yrs continous, you are going to need something a lot more industrial than that Isuzu...

SR

 

[RNeumann]

Yeah it is a huge load - I'm a website software designer by trade so I have multiple computers running at any given time. I worked out the number and its actually cheaper (after the initial purchase) to run an efficient diesel gen over getting power from the grid (not to mention the work required for that to be a possibility!) When I think about it more and more as I always am, maybe its the smarter route to simply get the Isuzu and not a stand by gen, power off the Isuzu for ten or so minutes at welcoming times to do maintenance. I figure if I keep up with all the required maintenance it will last me years to come as it's rated to run 24 hours a day 365. Claiming over 30k hours of use is very attractive to my mind. It's possible to wire a gen to a normal panel being a handy man I figure. What do you think?

Wiring a panel is fairly straightforward from my point of view. Ask me to spell, sing, dance, write or speak to crowds and not your guy. But mechanically I am shown something once and it's locked in. With that, panels are a matter of power in, and power out. Your biggest issue is the non standard nature of the generator specs and wiring. The bigger ones like you are looking at are way more inline with "normal" wiring though.

Like you said, read, watch videos and ask questions. I also use these. I like them so much I continue to buy the updates. They have electrical, mechanical etc.
Code Check Electrical: An Illustrated Guide to Wiring a Safe House: Redwood Kardon, Douglas Hansen, Paddy Morrissey: 9781621137788: Amazon.com: Books

 

[RNeumann]

How about a large UPS for backup? Go crazy and get the Tesla battery!

Is solar an option?

Btw everyone with a RV or gen should have one of these-

P3 P44 Kill A Watt Electricity Usage Monitor - Low Temperature Alarms - Amazon.com

 

[TractorGuy]

One problem with diesel generators is the need to KEEP them loaded. Run too long under a light load and you stand a chance of wet stacking the engine.

I have a 10KW diesel backup generator we use during power outages. For prolonged outages like the hurricane we just had I find myself searching for ways to keep it loaded. It will run my 3.5 ton package AC with the rest of the house but the outside temps during the outage were 65 degrees so we didn't need it. After I had the water heater warmed up and all the laundry done we had to resort to baking cookies. I would not want to search for ways to keep it loaded 24/7.

For an off grid house I would definitely look into solar with a backup generator. Most of the research I've done on this indicates it won't be cost effective if utility power is readily available. If it was going to cost 20K plus to connect to the grid I would rather spend that plus to stay off.

 

[Greenhorn18]

30,000 hrs is a LONG ways from 10 years!

For 10 yrs continous, you are going to need something a lot more industrial than that Isuzu...

SR

I didn't say anything about 10 years, I imagine at constant use at max it'll last me 2.5 years before I need to upgrade to a better one.