110 vs 220

[DustyDesertDweller]

Hi all, I'm currently building an off grid studio and workshop in the desert in Southern California and am contemplating whether I want to wire for 220v or not. the studio is about 400sq and I will be installing a mini split for heating and cooling. I used a BTU calculator to size the mini split and I plan on going with a 12k BTU unit. 110v 12kbtu units are plentiful by the looks of it. I will also be running a washer and propane/gas dryer which are also readily available in 110v. So far I don't have any plans for 220v devices but people often suggest to run 220v anyways. I am leaning towards avoiding 220v at the moment but with the option of wiring 220v later in the workshop if I get a tool that requires it (none of my tools require 220v but maybe down the line I will upgrade my welder to a 220v unit but no plans to in the near future). Probably my biggest reason for avoiding 220v at the moment is that I have two EGR 3k inverters and I like the idea that if one fails I still have a backup that is capable of running all devices rather than losing power to all 220v devices.

My main question for the forum is do any of you have any convincing arguments for running 220 now? And if I don't run 220v now, how would you recommend I set myself up for the possibility of wiring 220v painlessly in the future? The inverter/charger, batteries and breaker box will be located in my workshop so any 220v wiring I'd be doing in the future won't be going very far.

Thank you!

 

[chamilun]

220 would allow for more expandality in the future.

say a piece of equipment you want only works on 220.

also with 220 you are sharing loads on two legs instead of 1.

Id go 220 every time

 

[Glock24]

Hi, the real reason to use 220V vs 110V is that usually the 220V devices like AC units are more efficient and many high power draw devices require 220V.

If you don't have high power draw appliances that require 220V then I see no strong argument against sticking with 110V, at least for now.

Wiring for 220V is a good idea though, so you'll be ready in the future.

 

[chrisski]

Hi all, I'm currently building an off grid studio and workshop in the desert in Southern California and am contemplating whether I want to wire for 220v or not.

I recommend you go with 220 V.

I did a 3 kW build for my RV at 120 volts and my needs grew a bit, and now I can't install 220 Volt appliances like a mini-split AC.

American Split Phase still allows 120 volt legs. I'd prefer to wire the bus just once, and wire it as spit phase instead of going back later to fix it. Turning 120 volts into 240 takes a bit of time. Starting at 250 volts is not that much more money, and a bit of work saved in the long run.

An EG4-6000XP is much less expensive than the components I put it together. For a stationary build where space requirements are not a factor, that could help.

 

[dktool]

At the least run 4 conductors so it's easy to upgrade voltage later.
I would do 240 the first time.

 

[jorby]

Since you already have the inverters, install a 220v main panel and wire both poles to the same 120v inverter. You will have the path to upgrade to 220 if you ever need it, without buying a 220v split phase inverter now, when you don't need it.

EDIT: OK, OK, **** 240v **** FFS!

 

[Steve_S]

Corrections which are CRITICAL !
210-230 V is NOT USED IN USA ! Those are Asia, Europe, Africa's etc... VERY FEW NATIONS USE 240V @ 60HZ Split Phase.
Everyone else pretty much uses 210-230V @ 50 Hz SINGLE PHASE !
These are NOT Compatible in any way... STOP saying 220V, especially to Vendors/Suppliers who will think you are on European or other based grid.

US 240V/Split Phase is two 120V @ 60Hz legs. Every 240V Panell has 120V Breakers and when linked can output 240V.
240V in USA is used for Dryers, Stoves (even induction ones), Well Pumps, EV Chargers etc...
120V is all the common goodies like lights, refrigerator etc... By Default 120V is 15A or 20A and residential 240V up to 60A but usually not higher than 40A.

I am an OFF Gridder - fully solar powered with 51kWh of LFP Battery.
240V Installation provides all the 120V I need/want and have 240V for the few things that need it.
Do NOT cut yourself short as things are always changing and redoing thing sis cstly as well as a PITA, setup for a 240V Main Panel (Minimum 100A but better to be able to support 200A)

Here's the GOTCHA ! 240V/100A = 24,000W. 200A is Double the wattage.
Virtually all homes even with 100A Panels rarely ever see 100A being pulled unless you have something in the oven, the dryer going and the well pump (if 240V) kicks on, on top of lights, radio etc what ever else is running. NB: Teen Kids ADD LOAD ! They never turn off squat !

FYI, Most Heat Pumps, even the small ones prefer 240V, very few use 120V and those that do are A-Typically 120V/30A which is odd and also inefficient. Also, pretty much all built-in stove tops, including Induction ones are 240V/30A, some are 240V/20A but not many. Only the small portable ones are 120V.

Last Point and it is a $$$ WARNING !
Wire today for ALL possibilities. Copper is NOT cheap and will never get cheaper ! I have seen it go up 400% in < 10 years and now with the new tariffs, Ohh Lordie it's gonna get bad fast. 80% of US' copper comes from Canada ! on the 2nd that jumps 25-50% !

PRO-TIP: Stick to the Commonly available quality brands for your AC Supplies. Use Square-D Panels & Breakers, Southwire 14-awg for 120V/15A circuits, 12-awg for 120V/20A, 10-awg for 120V/30A. 8/3 Gauge for 240V/20A - 30A & 6/3 for 240V/40A. * Also depends on run length of the wire, always defer to a local electrician & local electrical code requirements. DO NOT BUY OFF BRAND / NO-NAME BRAND ANYTHING !!!

Hope it helps, Good Luck.
PS: AGAIN - Do NOT refer to 210/220/230V They DO NOT APPLY TOP USA !
You are 120/240V @ 60Hz,

 

[ricardocello]

The USA standardized on 120/240 VAC 60 Hz split-phase in 1967.

Before that, it was 115/230 VAC, and back before the 1940s, it was 110/220 VAC.
And in the 1880s, it was 110/220 VDC because of Edison.

I don’t know why people here still call it 110V or 115 or 220 or 230.
Unless they are really really ancient.

Now three-phase 120/208V, that is alive and well here.

 

[740GLE]

FYI, Most Heat Pumps, even the small ones prefer 240V, very few use 120V and those that do are A-Typically 120V/30A which is odd and also inefficient. Also, pretty much all built-in stove tops, including Induction ones are 240V/30A, some are 240V/20A but not many. Only the small portable ones are 120V.

9k and 12k mini splits at 120v are just about the same efficiency as their 240v counterparts. Like 20.5 vs 21 SEER2 ratings. I’m guessing the OP isn’t too concerned about heating.

If the OP already has 120v inverter/AIO and only 240v load would be the mini split, it make sense to future proof and wire a 120/240 panel for 120. A 12k mini split only needs 20a breaker.

I’d then used the saved money from not buying a new inverter on more insulation or shading to allow that mini split to work much less.

 

[TM48]

When you buy a load center it will be 240v. Wire it as 240v (only one more wire) and just feed it with one inverter so it will only have one leg hot. When you needs change it will already be there.

 

[DustyDesertDweller]

9k and 12k mini splits at 120v are just about the same efficiency as their 240v counterparts. Like 20.5 vs 21 SEER2 ratings. I’m guessing the OP isn’t too concerned about heating.

If the OP already has 120v inverter/AIO and only 240v load would be the mini split, it make sense to future proof and wire a 120/240 panel for 120. A 12k mini split only needs 20a breaker.

I’d then used the saved money from not buying a new inverter on more insulation or shading to allow that mini split to work much less.

Yes I'm not too concerned with heating and the walls are r19 and roof is r30. My two AIO inverters can do split phase if I choose to go down that path so I would like to future proof my system just in case.

When you buy a load center it will be 240v. Wire it as 240v (only one more wire) and just feed it with one inverter so it will only have one leg hot. When you needs change it will already be there.

Can you explain a little more? I was planning on connecting my two 3kw AIO inverters together in single phase for a total of 6kw. How do you recommend I then connect those to the load center?

 

[DPC]

STOP saying 220V, especially to Vendors/Suppliers who will think you are on European or other based grid.

220..... 220.... 220....

550......

2300 !

6900 ?

Bingo

 

[DPC]

Last Point and it is a $$$ WARNING !
Wire today for ALL possibilities. Copper is NOT cheap and will never get cheaper ! I have seen it go up 400% in < 10 years and now with the new tariffs, Ohh Lordie it's gonna get bad fast. 80% of US' copper comes from Canada ! on the 2nd that jumps 25-50% !

They tariff the Aluminum too don't forget.
Thats gonna cost.

And dont forget the nickel the cobalt and everything else.
Uranium lol...

 

[DPC]

The USA standardized on 120/240 VAC 60 Hz split-phase in 1967.

Before that, it was 115/230 VAC, and back before the 1940s, it was 110/220 VAC.
And in the 1880s, it was 110/220 VDC because of Edison.

I don’t know why people here still call it 110V or 115 or 220 or 230.
Unless they are really really ancient.

Now three-phase 120/208V, that is alive and well here.

There is even more weird stuff but you are correct.

Typicaly if I see 550 it was 25 cycle..
Modern stuff says 600.
In America you use 480 3 phase, maybe a bit of 600 I dont know how common.

There are some 220 three phase transformers with a centre tap to make an Edison three wire off one phase
That is exceedingly rare up here.

2300 25 cycle two phase for electric trains...
Ah the good old days.
I miss these little guys.

 

[Glock24]

The USA standardized on 120/240 VAC 60 Hz split-phase in 1967.

Before that, it was 115/230 VAC, and back before the 1940s, it was 110/220 VAC.
And in the 1880s, it was 110/220 VDC because of Edison.

I don’t know why people here still call it 110V or 115 or 220 or 230.
Unless they are really really ancient.

Now three-phase 120/208V, that is alive and well here.

Where I live we use 120/240VAC split phase and it's not the US.

People call it 110/220 or 120/240 and in reality voltage varies between around 110V to around 120V depending on the zone and time of day.

In my case it dips to 116V around noon and goes up to 122V a little past midnight.

Here's the past 7 days:

 

[DPC]

In my case it dips to 116V around noon and goes up to 122V a little past midnight.

Thats normal in a lot of places.
Most electrical equipment is fine if the voltage stays between + or - 5%. of 120 volts.
In the old days the swigs were more and the equipment was even more tollerant.
Half of Japan is 100 50hz and the other half 110 60hz....
All kinds of strange stuff out there.

 

[TM48]

Yes I'm not too concerned with heating and the walls are r19 and roof is r30. My two AIO inverters can do split phase if I choose to go down that path so I would like to future proof my system just in case.


Can you explain a little more? I was planning on connecting my two 3kw AIO inverters together in single phase for a total of 6kw. How do you recommend I then connect those to the load center?

If your inverters are capable of split phase operation I'd do that. If not but can be paralleled then you could double them up on one leg.(half the panel).

 

[GuyG]

When you buy a load center it will be 240v. Wire it as 240v (only one more wire) and just feed it with one inverter so it will only have one leg hot.

Hmm. There’s a safety issue whenever you wire up a split phase box for only one leg. Very clear and bold labeling is absolutely necessary, at a minimum. If you do connect wires to both line lugs (bad idea), make sure to cap off the other end of the unused wire with a Polaris or some similar method, and label it.

I came across a box once that apparently received power on only one leg. But I guess they were irked that only half the breaker slots worked. Guess what they did about that?

 

[jorby]

Yes, label it. If a 240v breaker is installed and wired to a 240v device, it won't work, but won't hurt anything either.

 

[740GLE]

Can you explain a little more? I was planning on connecting my two 3kw AIO inverters together in single phase for a total of 6kw. How do you recommend I then connect those to the load center?

I have a 100a square D panel I feed with my 24/3000 multiplus. I didn’t even bother connecting anything to the main panel lugs.

I back feed a 30 dual pole breaker with a jumper to both “legs”. All my breakers that I’m using are just 120v.

When you run your inverters in split phase but 90% of your large loads are 120v, IMO that leads you into having a possible unbalance issue with one leg having more than 3k and shutting down.

sure 240v future proofs you for future loads, but you’d also most likely need to upgrade your inverters, so just be prepared and planned for the upgrades.

 

[DustyDesertDweller]

I have a 100a square D panel I feed with my 24/3000 multiplus. I didn’t even bother connecting anything to the main panel lugs.

I back feed a 30 dual pole breaker with a jumper to both “legs”. All my breakers that I’m using are just 120v.

I've only built DC systems, I've never wired an AC panel so forgive my ignorance but I figure the main panel lugs is where you would normally connect the AC out of your inverter? If so, what's the reason for back feeding a 30 dual pole breaker instead?

When you run your inverters in split phase but 90% of your large loads are 120v, IMO that leads you into having a possible unbalance issue with one leg having more than 3k and shutting down.

sure 240v future proofs you for future loads, but you’d also most likely need to upgrade your inverters, so just be prepared and planned for the upgrades.

Yes, running split phase with literally every device being 120v seems wrong to me but people are fairly consistently advocating for running split phase 240v regardless and its hard for me to understand why. I need someone to explain this like I'm a 5 year old haha.

I am a fan of the idea of making it as easy as possible for future me to wire a 240v outlet or two in my shop next to where the breaker is but I am unclear on the best approach. It seems to me if I set up my panel with 120v only for now then in the future it would be as simple as changing the wire layout between the inverters and panel (they will be inches or feet apart) as well as inverter settings and then adding a 240v breaker to the panel and running a wire a couple feet to a 240v outlet. Is this at all accurate or is it much more complicated than that?

Future proofing the option of adding some 240v outlets later on probably also involves slightly oversizing my main panel? I should have about 10kw of solar with 30kwh of batteries powering a 120v shallow well water pump, two 120v mini splits, 120v power tools (table saw, compressor, welder, etc..) washer and gas dryer, lights, etc..). I'm thinking 8 or so 15a/20a circuits in total. Would a 100a panel suffice?

 

[pollenface]

If it were my thing that I was making for ME, I would not give 2 hoots what other people say I should do

If you are only planning on 110v loads, then so be it.

 

[DustyDesertDweller]

If it were my thing that I was making for ME, I would not give 2 hoots what other people say I should do

If you are only planning on 110v loads, then so be it.

I definitely hear that but also most people on here probably know more about this stuff than me. I've only set up a few simple DC solar systems. This will be my first time wiring an AC system so I'm open to getting informed on better options but so far I'm still scratching my head.

 

[pollenface]

I definitely hear that but also most people on here probably know more about this stuff than me. I've only set up a few simple DC solar systems. This will be my first time wiring an AC system so I'm open to getting informed on better options but so far I'm still scratching my head.

The most interesting thing I leaned is generally more volts (be it AC or DC) has less loss given the higher electrical pressure, or something....

110v @ 20a over 100ft on 9awg = 2.874% loss
220v @ 10a over 100ft on 9awg = 1.2933% loss

very interesting

 

[Glock24]

The most interesting thing I leaned is generally more volts (be it AC or DC) has less loss given the higher electrical pressure, or something....

110v @ 20a over 100ft on 9awg = 2.874% loss
220v @ 10a over 100ft on 9awg = 1.2933% loss

very interesting

Split phase carries 120V across two conductors, same as 120V, but you're able to carry more amps to the same device because the load is balanced between the two conductors.

Still, many devices are more efficient running in 240V vs 120V.