Help me size my inverter

[Stainless03]

Hurricane season is upon us in South Florida and I've convinced myself I need to build another run of the mill "portable" power station. But the more I read the more confused I get. I need a unit that will start up 12,000 btu stand up A/C unit, two refrigerators, and phone/laptop chargers overnight. The A/C requires 1100 running watts and I'll need roughly another 1000 watts for the other items. I began looking at the LV6548 style inverters or the 3k EG4 unit but they don't seem to have the required surge capacity to start an A/C that size. So at this point I've been looking at the Multiplus II 48/3000 or 48/5000. I know the 3kva will run 2400 watts constant which is enough, but will it have the surge capacity I need? Is there another inverter I should consider?

Currently I plan to charge the unit off of my 4500 watt(3500 constant) inverter generator during the day when needed, but down the road I'll add small amounts of solar. I expected to need two EG4 server rack 48v 5kwh batteries knowing that A/C uses an easy 1.1kw per hour. In the future I will likely use it as a UPS for a freezer or take it to my office to run computers/registers when the power goes out there.

And just out of curiosity.. How large of an inverter would I need to power up my 120v 2hp air compressor? My generator will start the motor with no load, but if there is pressure in the tank I have to be plugged into my washer outlet in the house. That's not a need, but it would be cool to have a plug in the garage that actually works for the compressor.(I have no intentions of staying at this house long term, so I'm not wasting money having it all wired right.)

Thanks guys!

 

[Deleted member 91418]

Will has a video where he goes over all sorts of inverters. While I must admit I have no knowledge on server-rack systems or all-in-ones, a section of that video says "get the biggest inverter you can afford", and he's got a good point. My boss's work RV has dozens -I mean dozens of inverters in the back bedroom. They all work like a charm, but he kept needing more power and thus needed more inverters capable of running bigger appliances.

Based on your needs for running an A/C, if the budget and system allows for it, I would get a couple of all-in-ones with the most pv allowed and A/C output. Even if it doesn't seem like a brilliant idea at first, it will allow you to easily add solar to it in the future.

It wouldn't hurt to over-size your inverter also. For example, I have a Giandel 600w pure sine wave (it's literally new to my system), but because all of my appliances running at once will only pull 350 watts, I still have enough clearance to not over-push the inverter. My boss (and a few members) have told me to over-size an inverter, as if it's ran to its maximum output all the time it can wear out it's components. For how small my foot-print is (an old Honda SUV) I know I won't be adding more appliances in the future; I physically can't lol. Therefore, 600w is plenty enough for me.

And I'm sure I don't need to say this part, but make sure you use proper protection items on your build! I don't know if it's just me, but I've been seeing a lot more fires/meltdowns this spring with quite a few systems. I even passed an RV on fire, which was caused by pv cables popping loose from their SCC.

 

[seneysolar]

Hurricane season is upon us in South Florida and I've convinced myself I need to build another run of the mill "portable" power station. But the more I read the more confused I get. I need a unit that will start up 12,000 btu stand up A/C unit, two refrigerators, and phone/laptop chargers overnight. The A/C requires 1100 running watts and I'll need roughly another 1000 watts for the other items. I began looking at the LV6548 style inverters or the 3k EG4 unit but they don't seem to have the required surge capacity to start an A/C that size. So at this point I've been looking at the Multiplus II 48/3000 or 48/5000. I know the 3kva will run 2400 watts constant which is enough, but will it have the surge capacity I need? Is there another inverter I should consider?

Currently I plan to charge the unit off of my 4500 watt(3500 constant) inverter generator during the day when needed, but down the road I'll add small amounts of solar. I expected to need two EG4 server rack 48v 5kwh batteries knowing that A/C uses an easy 1.1kw per hour. In the future I will likely use it as a UPS for a freezer or take it to my office to run computers/registers when the power goes out there.

And just out of curiosity.. How large of an inverter would I need to power up my 120v 2hp air compressor? My generator will start the motor with no load, but if there is pressure in the tank I have to be plugged into my washer outlet in the house. That's not a need, but it would be cool to have a plug in the garage that actually works for the compressor.(I have no intentions of staying at this house long term, so I'm not wasting money having it all wired right.)

Thanks guys!

Id be looking at a LF inverter to start A/C units and have 2 fridges running. Air compressors have different startup loads depending on tank empty/full - that is hard to say what yours will draw.

Something like this you wont overload, it can surge output to 18k watts for 20 seconds:

6000 WATT PURE SINE INVERTER CHARGER 48 VDC TO 120 VAC

6000 WATT PURE SINE INVERTER CHARGER 48 VDC TO 120 VAC | Built for the purpose of running your whole house (smaller home), business office or large RV.

theinverterstore.com

You'll get all sorts of recommendations. Victron is great but you really have to wrap your mind around the programming. What I like about Aims is the simplicity of it. The generator charging is adjustable with a rotary knob so you can easily adjust while charging if you want to load/unload the generator. These inverters have been around for years, its not new tech but its reliable and simple. No software updates, no Bluetooth, no apps, no programing of any sorts, no bugs.

Adding solar later will require a separate charge controller.

If not adding solar, it really doesn't make sense for an HF all in one unit. The surge capability are not the best either (but they are cheap and will probably be recommended here shortly). If you do go that route, pay attention to the MPPT features, as the higher voltage ones need a min amount of PV to start up.

 

[Deleted member 91418]

No software updates, no Bluetooth, no apps, no programing of any sorts, no bugs.

I long for the good old days of where everything was simple lol.

That 6000w inverter seems like a good idea though!

 

[Stainless03]

Id be looking at a LF inverter to start A/C units and have 2 fridges running. Air compressors have different startup loads depending on tank empty/full - that is hard to say what yours will draw.

Something like this you wont overload, it can surge output to 18k watts for 20 seconds:

6000 WATT PURE SINE INVERTER CHARGER 48 VDC TO 120 VAC

6000 WATT PURE SINE INVERTER CHARGER 48 VDC TO 120 VAC | Built for the purpose of running your whole house (smaller home), business office or large RV.

theinverterstore.com

You'll get all sorts of recommendations. Victron is great but you really have to wrap your mind around the programming. What I like about Aims is the simplicity of it. The generator charging is adjustable with a rotary knob so you can easily adjust while charging if you want to load/unload the generator. These inverters have been around for years, its not new tech but its reliable and simple. No software updates, no Bluetooth, no apps, no programing of any sorts, no bugs.

Adding solar later will require a separate charge controller.

If not adding solar, it really doesn't make sense for an HF all in one unit. The surge capability are not the best either (but they are cheap and will probably be recommended here shortly). If you do go that route, pay attention to the MPPT features, as the higher voltage ones need a min amount of PV to start up.

I hadn't even looked at the aims units actually. Seems like the 4k would be sized better for me, but that put it in to the same price range as the Victron 48/5000 which is so easy to expand. I appreciate the input, I'm going to look into these further. I just want to be sure I have a quality setup I can expand down the road when needed.

My concern isn't budget. While I don't want to waste money I hate the idea of getting a cheap HF inverter that can't start anything I need.

 

[Ampster]

How large of an inverter would I need to power up my 120v 2hp air compressor?

I have never gone through the aftermath of a hurricane. We did have a three day outage and I was only concerned with keeping my refrig cold, my phones charged and my lights on.

 

[seneysolar]

I hadn't even looked at the aims units actually. Seems like the 4k would be sized better for me, but that put it in to the same price range as the Victron 48/5000 which is so easy to expand. I appreciate the input, I'm going to look into these further. I just want to be sure I have a quality setup I can expand down the road when needed.

My concern isn't budget. While I don't want to waste money I hate the idea of getting a cheap HF inverter that can't start anything I need.

I power my cabin with the 4K version. I've been very happy with it, its about 7 years old now.

 

[Deleted member 91418]

I sadly can't give much of a verdict on my Giandel; it's not even been 24 hours with my use. But if cost isn't a huge importance, I say do as much research as possible, keep asking around (some real great input here) and get high quality inverters from a reputable brand. Even though Victron has me cringe due to a sour experience, they do have some very good products!

 

[DIYrich]

I would go for the eg4 6000xp. If that is not enough. You can parallel a second.

 

[Stainless03]

I have never gone through the aftermath of a hurricane. We did have a three day outage and I was only concerned with keeping my refrig cold, my phones charged and my lights on.

In the last few years my house as lost power for 8ish days once and 15 or 16 days the second time. My genset will power all of my critical loads, but keeping them feed with fuel becomes a major problem. None of the gas stations have fuel and ration what they do. At least with a backup battery I can run the generator more efficiently and even set a few panels outside to offset usage.

 

[Stainless03]

I would go for the eg4 6000xp. If that is not enough. You can parallel a second.

Why? Aren't those high wattage idle consumption with very little surge ability? Wouldn't that be vastly inferior to the 48/5000? I'm very knew at this, so I'm not trying to be sarcastic.

 

[DIYrich]

Why? Aren't those high wattage idle consumption with very little surge ability? Wouldn't that be vastly inferior to the 48/5000? I'm very knew at this, so I'm not trying to be sarcastic.

Cost. victron is great.

Multiplus 48/5000 is 5kw 120v single phase surge to 9kw.
6000xp is 6kw 120/240v split phase, surge to 12kw for 3 sec, and 11 kW for 5 sec.

 

[wdwtx2.0]

Why? Aren't those high wattage idle consumption with very little surge ability? Wouldn't that be vastly inferior to the 48/5000? I'm very knew at this, so I'm not trying to be sarcastic.

6000XP has 50 watts or less idle, less than 30 watts with PV.
Edit: The 6000EX low frequency had a high idle draw.

 

[Stainless03]

Another member here tried his stand up A/C on a single battery Victron 3k and it worked great. I'd rather spend the money and get the quality parts than the EG4 inverters.

 

[Stainless03]

Now that I've made this mornings impulse purchase it's time to start collecting the rest of the little parts I need. Thanks guys!