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Inverter generator or generator ?

Guda

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Nov 19, 2019
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Does my MPP Solar 48v All-In-One prefer sine wave or does it matter?
 
Generally for Battery Charging purposes it does not really matter "that much". The trick is to ensure the genset can stay within the correct frequency range (57-62hz) for North American power compatibility. 47-52hz for EU.

If your Inverter/Charger is also doing Pass-Through power to "house AC" while charging, then you will get Mod Sine passing through and THAT isn't good. Motors (fridge compressor , water pumps etc) will strain with Mod-Sine and of course there are electronics issues too that can arise.

IF possible, it is best to use a Pure Sine Inverter Genset, especially if you are using Pass-Through AC and running equipment that may be affected by less clean wave forms such as Mod-Sine.

I am not aware of any modern Generators using Square Sine (that s REALLY bad), they are typically Mod Sine or Pure Sine (Inverter generator).

AN ASIDE: If using a Generator to charge, pending on charger capacity.
My Inverter/Charger (Samlex) can deliver 100A Charge to 24V bank (programmable) but that only pulls <33A / <3800W at 120V.
 
Great info! Thank you!

I think I can select the source in my unit. I have to look & I am slammed. But basically if I am thinking correctly, I can tell the unit to use the battery always. So it would not be passing AC through.

I rented a 2000w generator for the weekend & when my compressor would turn on the compressor would over draw fault. I had to keep restating. Thats why I was thinking about the settings. Just haven't had the time to play with it.

I have some more generator related questions I'll start a new thread for.
 
Guda, as you may realize, you're likely to pay more per watt for an invertor type generator than not, but in addition to the invertor type producing a more stable sine wave when it's current is tested on an oscilloscope, another factor to consider is that inverter generators are much better capable of using less fuel when taxed less by appliances...not so with conventional generators.
 
Guda, as you may realize, you're likely to pay more per watt for an invertor type generator than not, but in addition to the invertor type producing a more stable sine wave when it's current is tested on an oscilloscope, another factor to consider is that inverter generators are much better capable of using less fuel when taxed less by appliances...not so with conventional generators.
Hey Arbee!

What I decided to do was buff this powerbox I already had. Here is that thread. I am making a video about the whole build. I will be a week ish before the video comes out. I keep needing parts. I am adding a bunch of options. Kinda fancy.
 
Unscientific gas generator efficiency:
I ran Army radio equipment on 10KW (SF-10) generator for almost 2 years. I could gauge the amount of fuel used because they ran off 55 gallon drums. I had two sets of generators which I would run for 12 hours on end 12 hours off. My radio equipment and accessories ran less than 5 kW load out of the 10KW generator capacity. Observations: I use less gasoline over a 12 hour period when I loaded the generator to 75%, anything less or anything more I use more fuel.
 
Wow, thats so much gas. I would have guessed they'ed used diesel for that. Must have been a cold environment?
 
1. The SF-5 (5KW) & SF-10 (10KW) were gas Army Gen's in 1967, the larger generators like 45KW were diesel. My opening comments were only to comment on efficiency, I can't remember the amount of fuel used. I wanted to point out that if you are selecting a backup generator for bad weather or emergencies to charge your batteries that under sizing it or oversizing it would lower your efficiency.
 
Standard gensets are PSW by design (usually). It's just the THD and subharmonics to watch, also keeping the frequency in range as the loads change. For off-grid purposes, the advantages of the inverter generators are basically lost IMHO. Typically (not always but most of the time) the bottom line is you want the genset to turn on, charge the batteries as quickly as possible (within reason), and shut off again.

So max charge rate + average loads + 25% = Genset KW

Around here, propane is less than half of gasoline or diesel so we always either convert or buy propane gensets with electric start. I'm going to be testing a Mebay DC30D soon to handle the dry contact from the inverters.
 
1. The SF-5 (5KW) & SF-10 (10KW) were gas Army Gen's in 1967, the larger generators like 45KW were diesel. My opening comments were only to comment on efficiency, I can't remember the amount of fuel used. I wanted to point out that if you are selecting a backup generator for bad weather or emergencies to charge your batteries that under sizing it or oversizing it would lower your efficiency.
Oh okay I see. Thank you!

Well, my AIO has variable charging. 10amp up to 110 amps at 10 amp intervals. To me ideal is not having a generator until I can get a high end model that works with the AIO automatically. But, having the correct battery, rest of my pv deployed & wind turbine will make it so I almost never, if not never need a generator. So, I want to get all that done before I pull the trigger on a expensive generator.

My truck will soon be able to charge my AIO at 10amps. So currently if I have 0 power from solar I'll have to run the truck for about 3.5 hours a day to make enough power to be okay. I've been working on this truck deal for over a month & in that time (solar minimum) I only had to use truck power for main power 2-3 times. Currently, I don't need much over & above solar, luckily.

Standard gensets are PSW by design (usually). It's just the THD and subharmonics to watch, also keeping the frequency in range as the loads change. For off-grid purposes, the advantages of the inverter generators are basically lost IMHO. Typically (not always but most of the time) the bottom line is you want the genset to turn on, charge the batteries as quickly as possible (within reason), and shut off again.
Interesting. Great info, thank you.

So max charge rate + average loads + 25% = Genset KW
110 amps is a huge generator & wire. 110amp AC wire gotta be huge

Around here, propane is less than half of gasoline or diesel so we always either convert or buy propane gensets with electric start. I'm going to be testing a Mebay DC30D soon to handle the dry contact from the inverters.
Before the fire (propane generator) I ran one every night. I really hated it but I was stuck. I had 3 20 gal tanks to run them. One exploded. I burned my hands up pulling the other 2 out. I like diesel now. Gas & propane are just to volatile for me now.

Thank you
 
Before the fire (propane generator) I ran one every night. I really hated it but I was stuck. I had 3 20 gal tanks to run them. One exploded. I burned my hands up pulling the other 2 out. I like diesel now. Gas & propane are just to volatile for me now.
I can completely understand your reservation with propane. Sounds like a terrible experience!

110 amps is a huge generator & wire. 110amp AC wire gotta be huge
If I'm understanding you correctly that's 110A @ 48V DC. That's basically 5.4KW or ~22A @ 240V. 10AWG would handle that easily depending on the run. Realistically though you'd be looking at an 8AWG or a 6AWG depending on loads and total run length. Either way shouldn't cost a fortune.

Well, my AIO has variable charging. 10amp up to 110 amps at 10 amp intervals. To me ideal is not having a generator until I can get a high end model that works with the AIO automatically. But, having the correct battery, rest of my pv deployed & wind turbine will make it so I almost never, if not never need a generator. So, I want to get all that done before I pull the trigger on a expensive generator.
Just a thought for the future: As long as you have an electric start generator of any kind, you typically can add an auto-gen start unit such as the Mebay DC20D MKII or DC30D. That will allow you to have a 2-wire or dry contact start from the inverter for automatic on/off operation. The gensets that include that functionality by default are few and far between (Generac Guardian) etc while also costing a mini fortune compare to a decent electric start genset with an auto-gen start unit added.
 
I can completely understand your reservation with propane. Sounds like a terrible experience!
Thanks man. Its a new year & its going to be awesome.

If I'm understanding you correctly that's 110A @ 48V DC. That's basically 5.4KW or ~22A @ 240V. 10AWG would handle that easily depending on the run. Realistically though you'd be looking at an 8AWG or a 6AWG depending on loads and total run length. Either way shouldn't cost a fortune.
Hum, forgive my lack of specs. I am not sure how the AIO works. But, it takes AC for non solar charging. I am pretty sure it will take 110amps at 120V. I think. Its been a few since I fooled with the AC charging settings. But, I seam to remember it going that high. No idea how I'd wire for that.
Just a thought for the future: As long as you have an electric start generator of any kind, you typically can add an auto-gen start unit such as the Mebay DC20D MKII or DC30D. That will allow you to have a 2-wire or dry contact start from the inverter for automatic on/off operation. The gensets that include that functionality by default are few and far between (Generac Guardian) etc while also costing a mini fortune compare to a decent electric start genset with an auto-gen start unit added.
Oh wow. Thats pretty sweet.

I'd prefer a diesel generator. The type that is installed. Like heavy equipment type. For some reason my backhoe starts no problem in the cold, but not my Powerstroke. Not sure if one what I am talking about has to run a block heater or not. But I might never need it. Wind & solar is great where I am. Huge solar farms all around. No big wind turbines around, but tons of little ones. I had one I lost in the fire, it blew like crazy all the time. With a new battery & a wind turbine ($5000) I literally might never need a generator.

I am in the process of making it so my truck can charge my AIO at 10amp. I wanted 20amp but the wiring would all have to be beefed up to 4/0 & thats crazy a lot. I still have to upgrade the alternator wire to get 10amp safely. I'm going to replace that with 4/0. Still trying to figure out what connector to use to connect to the alternator. Might just be a weird lug.
 
Hum, forgive my lack of specs. I am not sure how the AIO works. But, it takes AC for non solar charging. I am pretty sure it will take 110amps at 120V. I think. Its been a few since I fooled with the AC charging settings. But, I seam to remember it going that high. No idea how I'd wire for that.
What's the model of your inverter? 110A @ 120V input would be 13.2KW. That's crazy high for a single inverter. That's more than 2 SMA SI6048's or a single 15KW Quattro's charging capacity.

I am in the process of making it so my truck can charge my AIO at 10amp. I wanted 20amp but the wiring would all have to be beefed up to 4/0 & thats crazy a lot. I still have to upgrade the alternator wire to get 10amp safely. I'm going to replace that with 4/0. Still trying to figure out what connector to use to connect to the alternator. Might just be a weird lug.
4/0 is rated for ~230A (varies based on several specs). Seems odd that you would need that size wire for charging at 10A. No matter the voltage, 10A could be carried by a 12 or 14 gauge wire. Unless you are saying that you are converting it from a lower voltage/higher current somewhere along the way and in that case you need the larger wire for the lower voltage stage.

Would you be interested in sharing your wiring configuration/schematic for charging with your truck? I'm just a little curious but no worries if not.

I'd prefer a diesel generator. The type that is installed. Like heavy equipment type. For some reason my backhoe starts no problem in the cold, but not my Powerstroke. Not sure if one what I am talking about has to run a block heater or not. But I might never need it. Wind & solar is great where I am. Huge solar farms all around. No big wind turbines around, but tons of little ones. I had one I lost in the fire, it blew like crazy all the time. With a new battery & a wind turbine ($5000) I literally might never need a generator.
Sounds like a plan (no need for a genset). If you do get a diesel for backup, the lower end/cheapest auto-gen start units are usually designed/programmed for diesels out of the gate. With heater control and all. They are actually a little more difficult to configure for any type of gas generator (usually).
 
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What's the model of your inverter? 110A @ 120V input would be 13.2KW. That's crazy high for a single inverter. That's more than 2 SMA SI6048's or a single 15KW Quattro's charging capacity.

I think it says 60amps... Oops. Going to have to see what I was looking at.

4/0 is rated for ~230A (varies based on several specs). Seems odd that you would need that size wire for charging at 10A. No matter the voltage, 10A could be carried by a 12 or 14 gauge wire. Unless you are saying that you are converting it from a lower voltage/higher current somewhere along the way and in that case you need the larger wire for the lower voltage stage.
I need to go up to 4/0 as my alternator is 250a. I need to 4/0 from alternator to truck battery ASAP. I think I have 1/0 from the truck battery to the system in the back. Currently its like 8awg-10awg. Thats fine for what the truck needs but the inverters can draw more power than even the 1/0 can handle.

I was shooting for 20amps, But to get 20amps I'd need to upgrade the 1/0 run to 4/0. And then there is other stuff like Anderson connectors, solenoid, & maybe other stuff that may or may not need to be upgraded. So I am okay with the 10amp. Worst of the worst days are like 3-4 hours of charge time. Super rare tho. Since I installed my winter array, only a few days I needed just a bit more power.

Yes, the power cord that runs the AC could be a lower rated wire size. TBH that wire (aside from the plug) can handle 30amps. Its a long run & maybe some day I'll have 20amp to charge with

Would you be interested in sharing your wiring configuration/schematic for charging with your truck? I'm just a little curious but no worries if not.
I am making a video about the whole build. Its started off with me needing power, living in motel everything a mess after fire. Foolishly I bought this. Well long story short it was a lemon & under powered poo. You might be able to see some wiring specks on their site. So there is a entire system that I am building another system on top of. I am adding bells, whistles & the kitchen sink.

I ran the block heater plug back to the box to run off the low power system on a switch. I added a converter that connects to a cord real to easily plug the truck in & charge it without turning it on. And a 120v 3000w inverter. I will also be adding a SCC in a few months.

The inverter thats in the box is 115v 2000w. Just clicks right off when plugged in to the AIO. 10a is like 1200w. 2000w at 115v is like a waste tbh. Nothing likes 115v.

Sounds like a plan (no need for a genset). If you do get a diesel for backup, the lower end/cheapest auto-gen start units are usually designed/programmed for diesels out of the gate. With heater control and all. They are actually a little more difficult to configure for any type of gas generator (usually).
A plan I hope to avoid. Wind & solar with the correct battery. Literally might never need any fuel burning to make power.
 
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