Off grid 220 volt a/c help

Dskimmd

I live in Mali West Africa. I'm building an off-grid yurt roofed house. I have 2000 watts of panels and 8000 watts of batteries. I also have 800 watts of panels powering a lorenz well pump. I have a magnum 4400 inverter and I am using two 120v outputs on it to bring 240v to my American circuit breaker. I have a 240v breaker wired to a Mitsubishi minisplit A/C that requires 220v single phase 2 wire in without a neutral, only a ground. At the outside unit where the hot comes in I read 120v on each wire relative to the ground but the a/c still does not power on and when I read the two hot wires, I don't get 240v. What am I doing wrong? Thanks!

boonhauler

Re: Off grid 220 volt a/c help

What's the model number of the inverter? Did you check to see if the inverter is putting out 240 VAC? What around the hertz, 50 - 60?

BB.

Re: Off grid 220 volt a/c help

Welcome to the forum Dskimmd!

First, 8,000 Watts of Batteries... If that is a 48 volt battery bank you have:

8,000 Watt*Hours of batteries / 48 volt battery bus = 166 AH battery bank

That sounds a bit small to run a 4,400 Watt battery bank.... Normally, we would be suggesting closer to a 440 Amp*Hour @ 48 volt minimum (if you plan on pulling >~1,670 Watts of continuous power from the AC inverter) (minimum sizing rule of thumb for the battery bank.

For the US/North America, our 120/240 Split Phase power is not that complicated... Basically our line power is a center-tapped transformer:

||(

---

120 volt "Red"
||(
||(

---

Neutral "White"
||(
||(

---

120 volt "Black"

And if you draw power between Line-Red and Line-Black, you get your 240 VAC @ 60 Hz.

For a ~240 VAC power system, you could just ignore the Neutral (don't wire it to anything). The Inverter may tie the Neutral to its "green wire/chassis" ground, or it may not (in the US, we typically tie Neutral White to Green wire safety ground in the main circuit breaker panel--AC inverters sometimes will be wired with the neutral tied to their internal chassis/green wire ground). The green wire ground is usually tied to a long ground rod (~8-10 feet driven into the earth) and/or tied to the metal cold water pipe (and to any other large metal things in the home, like plumbing, stove, etc.--So you do not get shocked if you touch the White wire to any grounded items in the home/office).

You care, because you don't want a sort on the Red or Black to take your inverter chassis to 120 VAC with respect to ground.

The next question--For US/North America, we run 60 Hz (cycles per second) AC power--Typically 230 VAC power is 50 Hz AC. The mini-split AC system may, or may not, care about the 50/60 Hz issue. That would be my first question.

Next, if you do not see 240 VAC wires at your AC power connection... Make sure you are connected, one black/one red, to each of the L1/L2 outputs of the AC inverter (or LA/LB, whatever they are named).

If you see zero VAC, then it sounds like you are tied to one output connection only. If you see 120 VAC, then one of the hot wires is tied to the Neutral (center tap) of the inverter output.

Is the inverter operational? Do you have good battery bank voltage?

-Bill

Cariboocoot

Re: Off grid 220 volt a/c help

Welcome to the forum.

I think we need to check the inverter model. Is it MS4448PAE?
That should have two "hot" connections and one "neutral" for both AC IN and AC OUT.
You get 120 VAC between either hot and neutral or 240 VAC between the two hots.
The neutral line is normally bonded to ground. Do no take a Voltage reading from hot to ground but between the two hot wires. If it does not read 240 VAC something is wrong with the inverter.
Note that Hot 1 OUT is separated from Hot 2 Out by two neutral connections.
According to the manual the connections are:
AC Hot 1 IN
AC Hot 2 IN
AC Hot 1 OUT
AC Neutral
AC Neutral
AC Hot 2 OUT

To my mind this is a strange way to do it.

Dskimmd

Re: Off grid 220 volt a/c help

I'm not at the site do I can't tell you the exact model. It is a MS-AE series 4400 watt and can output 120 and 240 w/o having to stack.

Dskimmd

Re: Off grid 220 volt a/c help

My mini split is from the US so it is 220v 60hz. It has an L1 and L2 input w/o a neutral. The manual says 220 volts single phase 2 wire input. Should I take 120 from only one side (phase) of the breaker instead of using a 240 breaker which is split phase?

BB.

Re: Off grid 220 volt a/c help

In the US, both L1 and L2 have 120 VAC to ground/neutral.

We use two pole breakers with a "ganged switch" so that if there is a sort anywhere (hot to hot, Red to ground, Black to ground), it will trip 1 side of the breaker, which will trip both breakers off.

In theory, you can use just one breaker in one hot lead to the A/C system... However, in reality, you should use a breaker in L1 and L2 for safety. Especially if the Neutral is bonded to earth/safety/green wire ground.

-Bill

Dskimmd

Re: Off grid 220 volt a/c help

It is MS-AE so it is just as you described. The two AC hot outs are separated.

solar_dave

Re: Off grid 220 volt a/c help

Dskimmd wrote: »

It is MS-AE so it is just as you described. The two AC hot outs are separated.

so you get 240 ish across the 2 hots? does the inverter kick out? Does the AC just fail to start? Got a DC clamp meter? Got an AC clamp meter? How big is the wiring from the battery to the inverter?

Cariboocoot

Re: Off grid 220 volt a/c help

Dskimmd wrote: »

My mini split is from the US so it is 220v 60hz. It has an L1 and L2 input w/o a neutral. The manual says 220 volts single phase 2 wire input. Should I take 120 from only one side (phase) of the breaker instead of using a 240 breaker which is split phase?

The minisplit should be wired to L1 and L2 through a double-gang breaker.
But what you will have to check is that the inverter is actually putting out the 240 VAC. This may require turning off the inverter and disconnecting all AC wires IN and OUT ad checking directly at the inverter's output terminals. That will confirm whether or not it is working properly. If it is it will be a matter of checking the output wiring to see where there is a mistake preventing the A/C from getting AC.

BTW, the old North American power standard was 110/220 60 Hz. A few years back they upped the Voltage to 120/240 but essentially it is the same thing. We just use the higher numbers now as default.

Dskimmd

Re: Off grid 220 volt a/c help

Thanks all for your welcome and responses. I'm not saavy to all of this and have been learning on the go.
On my inverter, there are two ac hot outs which are 180 degrees out of phase. I have the two hots going to my breaker, one yo each side just like in the US. Is this two phase or split phase? Is there a difference?
When I check L1 or L2 ac in on the minisplit a/c against neutral they each read 120v. When I check them against each other I get <1 volt and not 240. I'll have to check at the box to see if I'm really getting 240 out.
The wiring out from the inverter was pretty straight forward. If the box isn't 240, I'll crack the inverter and check to see if I'm really getting 240. I don'g know the wire size from the battery but they are huge cables. It was all put together for me in the states. I added the second hotbout to get 240.

Cariboocoot

Re: Off grid 220 volt a/c help

There is no "two phase": the NA standard is single phase, 240 VAC. It gets 'split' as 120 VAC/120 VAC in reference to neutral.

When I check them against each other I get <1 volt and not 240.

That is a problem. Possibly bad inverter problem. But it is best to check with all AC wiring disconnected because it is possible the problem lies elsewhere.

Photowhit

Re: Off grid 220 volt a/c help

Dskimmd wrote: »

I added the second hotbout to get 240.

Not sure what this means...

So you have a system wired in the states, using a breaker box from the states, does your beaker appear as a double breaker? A breaker box has a neutral and 2 hot wires; here is an illustration;

Attachment not found.

Hot wires go to the 'A' and 'B' (through the main breaker, typically at the top )and the neutral to the buss bars on either side(where the white wires are connected.

The Breaker for a 220/240 uses both 'hot' wires and will be a double breaker utilizing the 2 hot wires; This illustration show both 120 and 240 breakers;

Attachment not found.

A 240 connection will have a red and black wire going to either side of the double breaker, and a neutral, and a 120 a single hot wire and a neutral...

Here is the layout of the Magnum 4448 PAE connections, from their PDF;

Attachment not found.

This should help you trouble shoot your situation, There are line ins for charging from an outside AC source, typically grid or generator, and the line outs should go to breakers, often one at the power center and then at the breaker box.

inetdog

Re: Off grid 220 volt a/c help

Quick guess:
The Inverter has only a 120V output and the second output connector is just in parallel with the first, maybe with a separate fuse. Leaving you with <1V between the two.
You need to get a transformer (or autotransformer) to reverse the phase of one of the outputs so that you will have your 240V.

Or just get a 240V inverter. Trying to get a second 120V inverter and synchronize it to the first will only be possible if they are the same brand and model and they support such a feature by using a synchronizing cable between the two.

SkiDoo55

Re: Off grid 220 volt a/c help

As "Photowith" suggested need to make sure you are feeding thru your breaker panel with a double pole Breaker, and you aren't using a twin single pole breaker, which only picks up one leg of the feed vs; the double pole which picks up both legs to feed thru to load.

mike95490

Re: Off grid 220 volt a/c help

inetdog wrote: »

Quick guess:
The Inverter has only a 120V output and the second output connector is just in parallel with the first......

Some inverters can be "stacked" to double the output amps, and some stacked to double the output volts. The manual tells all.