I am thinking to leave both positive and negative floating in reference to ground and use isolation monitor instead. This way if I come in contact with one wire I will not feel any shock but isolation monitor should pick it up and shutoff power.
That's what I observed in my test from day before. DC caps stay live as long as 120Vac is present.Once it is plugged in to 120vac outlet the HVDC likely stays live whether unit is running or not.
There is a 350V rail inside any 240V AIO. Does that count?Nice work ! Are there practical 12V or 24V to 280V boost converters? Hmm I'd love to run my 230VAC mini split on direct 24V DC someday
Thanks! Not that I am aware of anything practical. There are dc-dc boost modules on aliexpress but definitely not something plug and play.Nice work ! Are there practical 12V or 24V to 280V boost converters?
As long as it stays below 360V i guess you could tap hvdc bus from one of those inverters. But some of them like the Growatt 5000es have 450v bus that may be too high for this air conditioner.There is a 350V rail inside any 240V AIO. Does that count?
Got it. Well if someone is going to do this surgery they should test first and ask aroundAs long as it stays below 360V i guess you could tap hvdc bus from one of those inverters. But some of them like the Growatt 5000es have 450v bus that may be too high for this air conditioner.
Tapping dc bus allows for slightly higher efficiency and avoiding issues like flickering lights. A suitable AIO unit will have to be tested and potentially firmware modified. But my goal is 350Vdc loads in the house like inverter based air conditioners, instant water heaters coupled directly to 350Vdc battery which is powered by high voltage DC rooftop solar strings. For cooking I think I can use 240Vac powered induction cook tops that must be also rectifying 240Vac up to 340 - 400Vdc. This way most high power loads in the house are kept on hvdc avoiding the need for big and expensive 48v to 120/240v inverters. And added benefit is redundancy since there is no inverter.I’m not sure if there is value to tapping HVDC vs using the inverter output.
One thing I’d love to know from this is how it affects the noise signature from the induction.For cooking I think I can use 240Vac powered induction cook tops that must be also rectifying 240Vac up to 340 - 400Vdc.
It would be silent if PWM frequency is above human hearing upper frequency limit. But I never tried induction cooktop before. I may get one of those table top single burner units to experiment with.So would it sound better?
It would be silent if PWM frequency is above human hearing upper frequency limit. But I never tried induction cooktop before. I may get one of those table top single burner units to experiment with.
This forum is getting so big that some threads get lost in the torrent of new posts. Not a bad thing but does result in some interesting threads getting pushed down quickly. I usually browse by what's new.Dunno how i missed this the whole time.
My next goal in this project is to install DC modded mini split. Will have this Midea run for another summer. It accomplished its main task of proving that inverter ACs can run on DC. That was the major reason I bought it to replace perfectly fine 5k BTU single speed box.Mine has been sitting dormant since i installed a mini split in my room
Excellent work, I'm going to be installing this exact model into my RV and would love to have the choice of AC or DC. Do you use a switch to choose between the two before powering on or does it not back feed in any way? Have you tested DC draw and amps with a "kilowatt" meter during use on a really hot day yet? Also, could you please give an estimate of the efficiency difference between the two using this mod or just AC plugged in? Thank you.Installed junction box outside to route AC and DC power through.