Electrical Question - 208/230V

[C5c5]

Originally Posted by Old Scout

Tfryman--who mentioned European????? ….the OP did!!! but the "real" question is: is it 208-230v double-pole or single-pole? I "assume" OP's split AC is double-pole US std but not all RV breaker boxes accommodate phased 240v double-pole breakers....that is, below the main breaker...also, typical 7500 watt genset isn't phased either, believe 10 and 12k are?????? without knowing the "electrical IQ" of the OP, providing advice on this forum is always problematic.....

I am an electrical mechanic for rotary wing aircraft. I know electrical theory and aircraft systems. When it comes to residential, I am not as familiar.

[Old Scout]

C5c5….no offense to you at all.....you are asking the right questions...key here is that residential 240v appliances are two phased hots, a ground, and sometimes a neutral. Many RVs are wired for 50 amp service [two hots, neutral and ground], but most RV wiring doesn't support phased 240v applications.

[aether_one]

Originally Posted by Old Scout

Tfryman--who mentioned European????? ….the OP did!!! but the "real" question is: is it 208-230v double-pole or single-pole? I "assume" OP's split AC is double-pole US std but not all RV breaker boxes accommodate phased 240v double-pole breakers....that is, below the main breaker...also, typical 7500 watt genset isn't phased either, believe 10 and 12k are?????? without knowing the "electrical IQ" of the OP, providing advice on this forum is always problematic.....

Yes, he did ask about a "European power setup" but his mini-split is not European standard - 60 Hz is NA.

[paul65k]

Originally Posted by jacwjames

One problem you may have is trying to run the mini split on the generator. You would need a generator that actually makes the 230/240 volt power >>> two 120 volt circuits with the correct phasing.

My generator provides two 120 volt circuits on the same phase so I cannot run a 240-volt appliance.

This is a major consideration

Typically true 240V RV generators start at 12KW

[C5c5]

Thank all for the input!

There are some conflicting opinions here, but it seems the general idea is yes, I can install a 208/230V single phase 60Hz minisplit in my motorhome.

I've spoken to others who have suggested that so long as the minisplit is on its own dedicated properly sized inverter, it should work. This would for shore power use only.

If I wanted to have generator back-up, then I might run into problems from phasing.

[Old Scout]

…"dedicated properly sized inverter???????"..... have no idea what this is about--you are not going to run off bats?

[C5c5]

Originally Posted by Old Scout

…"dedicated properly sized inverter???????"..... have no idea what this is about--you are not going to run off bats?

Yes, I will be getting a very large solar system in a few months. I however for the short future will be running everything on shorepower. I am getting on the road full-time sooner than anticipated and can't install everything in time.

As far as the inverter, I'm told that it needs to be able to handle 208/230V.

[KanzKran]

The 208V is referring to a Y-connected 208Y/120V three-phase system, which is common in places like apartment buildings and small commercial spaces. You get 208V phase-to-phase, and 120V phase-to-neutral.

But the 208V is single-phase, just like 240V in your house panel is single-phase. So all that 208/230V means is that it's '208V compatible'. Many induction motors show something similar on the nameplate, like 208-230/115V for a dual-voltage motor. It just means it's rated for full output at 208V, as well as 230V, and 115V when reconnected for low voltage. Many if not most small induction motors are NOT 208V rated, unless it says so on the nameplate. Your unit is.

So in a nutshell, if you can connect to a 240V circuit (see the post above about the quad breaker with handle ties), you can run it on your 120/240V power.

Edit: By the way, induction motors built to the NEMA MG-1 standard are rated 115V, 200V, 230V, 460V, and 575V, and are intended to operate on 120V, 208V, 240V, 480V, and 600V (mostly in Canada), respectively, systems. Many motors still show 208V for a 208V system, though it should be 200V to conform to the 4%+ voltage allowance that's built into these motors, so those are a bit of an oddity.

[C5c5]

Originally Posted by KanzKran

The 208V is referring to a Y-connected 208Y/120V three-phase system, which is common in places like apartment buildings and small commercial spaces. You get 208V phase-to-phase, and 120V phase-to-neutral.

But the 208V is single-phase, just like 240V in your house panel is single-phase. So all that 208/230V means is that it's '208V compatible'. Many induction motors show something similar on the nameplate, like 208-230/115V for a dual-voltage motor. It just means it's rated for full output at 208V, as well as 230V, and 115V when reconnected for low voltage. Many if not most small induction motors are NOT 208V rated, unless it says so on the nameplate. Your unit is.

So in a nutshell, if you can connect to a 240V circuit (see the post above about the quad breaker with handle ties), you can run it on your 120/240V power.

Edit: By the way, induction motors built to the NEMA MG-1 standard are rated 115V, 200V, 230V, 460V, and 575V, and are intended to operate on 120V, 208V, 240V, 480V, and 600V (mostly in Canada), respectively, systems. Many motors still show 208V for a 208V system, though it should be 200V to conform to the 4%+ voltage allowance that's built into these motors, so those are a bit of an oddity.

Thank you!

[KanzKran]

Just for completeness, here's a 1 hp motor nameplate showing 115/208-230V, with full load current numbers that correspond to the different line voltages, and the reduced service factor at 208V from 1.15 down to 1.0, since it's basically an undervoltage condition. But it's still designed and rated for continuous full hp output at 208V line voltage as well as 240V. As is yours, even though it'll be working on a 240V system since RVs aren't typically connected to 208V power.

Yours just can't be connected for 120V systems, while this motor can.

And here's a 208-230V (only) motor nameplate, which is more like yours.

[Old Scout]

…."big solar panels"...and big battery bank and big inverter with phase output????....and big$$$$$$$ too.....yes, you will certainly going "big"!!!!!!

[Xmcdog]

As long as you are roughly within range you will be fine. Most local domestic supply is around 242 volts 60 hz.

I have installed hundreds of mini splits with no voltage issues. Max limit I am told is 253 volts.

[Xmcdog]

Just a little more trivia for you. The compressor motors in a mini split are 3 phase DC motors running on about 360 volts.
This gives them a soft start and the initial amp draw is about 0.92 amps on startup for a 15 k btu unit.

[Xmcdog]

Originally Posted by KanzKran

Just for completeness, here's a 1 hp motor nameplate showing 115/208-230V, with full load current numbers that correspond to the different line voltages, and the reduced service factor at 208V from 1.15 down to 1.0, since it's basically an undervoltage condition. But it's still designed and rated for continuous full hp output at 208V line voltage as well as 240V. As is yours, even though it'll be working on a 240V system since RVs aren't typically connected to 208V power.

Yours just can't be connected for 120V systems, while this motor can.

And here's a 208-230V (only) motor nameplate, which is more like yours.

Sorry to disagree but mini splits are using 3 phase DC motors with inverter control. Different animal.