inverter air con

[Kappy]

Good Morning.

Comments noted, will need to relocate invertor back to where it was, seemed like a good idea at the time.

240 Volt isolated by manual switch.

Seems my victory was maybe premature.

Well last night I ran A/C for about 3 hours and when turned off was showing 90%.

So over night I was running electric side of Suburban HWS, microwave on standby, 2 TV's on standby and 24 volt fridge and this morning before the sun had any effect on panel, notice an alarm coming from Bus.

On inspection invertor fault light was on and controller was showing 0% nothing coming in and nothing going out Amp wise but was displaying 23.7 volts I guess battery voltage.

I so I guess I'm at an impasse.

Although I do believe either or both the controller and invertor has a low voltage protection.

Kappy,

What is your SOC on the meter when this happened?
I suspect the inverter is not going thru the shunt and being missed being read by the meter, as per my last post.

Triptracks

I didn't see the SOC when the alarm went off, it was overnight,

I don 't understand this bypassing the shunt, I haven't I don't think.

Correct me if I'm wrong I understood both or either Controller and Invertor have a safety to prevent total draining.

Also would have thought a 2000 watt invertor would handle a 1400 watt HWS cycling in as was already hot from when AC was connected.

The 24 V fridge/house light seem to be wired direct from the controller.

[triptracks]

what meter told you the SOC was 90%?

[Kappy]

I have a Steca PR1010-3030 solar controller.

From what I can gather the Steca is a pretty reliable controller and would have shut the system down at 22,2 volts

In the morning the controller displayed SOC 0% but show the voltage as 23.7 confirmed with multimeter.

So the batteries recovered a little from when the alarm has been activated, time unknown.

Could be a week battery, next step to load test.

Yesterday after SOC at 100% I ran the inverter all day with TV, 24 Volt fridge, plus portable A/C alternating with a 2 1/2 HP split A/C together with the electric side of HWS. and SOC 100% all day slight variation in Amps.

The other thing I discovered was with A/C running the power would Cycle off and on about every 3 minutes for about a second.

Running a Powertech 24v modified Square wave (MSW) 2000w (MI-5116), that I read elsewhere did the exact same thing with A/C's and fans .

So may need to change invertor as well.

In any event the solar panels are coming off to be relocated so I can fit my new Dometic Harrier Invertor A/C.

[triptracks]

Ok, a number of things here.

1. To read the SOC, any and all loads would need to be connected to the load terminals of the Steca Regulator. Your inverter is not wired this way, so the SOC is not being reflected in the reading. DO NOT modify this, however, as the Steca will not handle the inverter load especially when running the A/C.

2. a Modified Sine wave (MSW) aka square wave, inverter is not recommended especially for running motor loads and some electronics. I suggest you replace this with a pure sine wave inverter. The power cycling off every 3 minutes is trying to tell you something - things are not right, and I would imagine you are overloading that inverter especially with A/C and HWS running at the same time. Standard electric HWS use 1100W; your inverter is only rated to 2000W, leaving 900w for the A/C. Add to that it is modified sine wave.

3. I suggest you install a BMV700 or 702 battery monitor with shunt. This will tell you the true battery load and the SOC.

4. I wouldn't suggest the Harriet is a good solution. Is your existing A/C an inverter or IBIS roof rattler? I would suggest a good quality inverter type split system A/C would use less power, be quieter and run more efficiently.

5. These types of loads are not kind to GEL or AGM batteries. You should consider LiFePO4 if you wish to run these types of loads for long periods off your batteries.

[dapope]

In the case of the harrier, for us it was the best solution. Not the most efficient, but the most practical. That can also be important.

[Kappy]

Ok, a number of things here.

1. To read the SOC, any and all loads would need to be connected to the load terminals of the Steca Regulator. Your inverter is not wired this way, so the SOC is not being reflected in the reading. DO NOT modify this, however, as the Steca will not handle the inverter load especially when running the A/C.

2. a Modified Sine wave (MSW) aka square wave, inverter is not recommended especially for running motor loads and some electronics. I suggest you replace this with a pure sine wave inverter. The power cycling off every 3 minutes is trying to tell you something - things are not right, and I would imagine you are overloading that inverter especially with A/C and HWS running at the same time. Standard electric HWS use 1100W; your inverter is only rated to 2000W, leaving 900w for the A/C. Add to that it is modified sine wave.

3. I suggest you install a BMV700 or 702 battery monitor with shunt. This will tell you the true battery load and the SOC.

4. I wouldn't suggest the Harriet is a good solution. Is your existing A/C an inverter or IBIS roof rattler? I would suggest a good quality inverter type split system A/C would use less power, be quieter and run more efficiently.

5. These types of loads are not kind to GEL or AGM batteries. You should consider LiFePO4 if you wish to run these types of loads for long periods off your batteries.

I'm really quite new to all this, so discovering some flaws in my system.

The MSW is out the window.

Getting my batteries load tested today for peace of mind.

The Dometic Harrier is an inverter type A/C, fitted a normal invertor split system just wasn't achievable, so had to go with the roof top.

According to Dometic it has a draw at cooling of 6.5 amps.

I will be fitting a BMV700 when I refit everything.

[T1 Terry]

The 6.5 amps is possibly a peak draw @ 240vac, 6.5 x 240 = 1560w x 10% for inverter losses = 1760w, so a 2000w inverter would be needed and the peak draw should be around 140 amps from the 12v battery. Being an inverter type system that peak is at the beginning of the cooling/warming cycle, not at start up, it slowly builds up to that and may never actually reach the peak before it starts to cycle back down.
From what I've seen the 3.5kW Mitsubishi split system I'm doing the testing on draws 3,000w at full song with both head units in operation, but one head unit on eco-cool between 900w and 450w, so there is quite a range in power draw depending on just what function the unit is doing at the time.

T1 Terry

[triptracks]

Interesting, Terry.

I have never seen any more than 1500W draw from my 5kW split system, so 3000W surprises me with a 3.5kW system even with two heads.

While the Harrier is an inverter system, it still is not as efficient (power and cooling), or as quiet, as the split systems and expensive in comparison.
I think dapope (Martin) has installed one of these and reported this also.

I can run the 5kW using a 2600W inverter and still run the HWS or boil the kettle (2400W) or use the washing machine (7kg using hot wash).

[dapope]

140 a draw at 12v max fits with my figures that I have seen. Normally it doesnt sit that high of course. As we are in the Pilbara, its a perfect testing environment, I suspect a split system would struggle at times as well. Already we have had 45 deg days..and 40 is not uncommon, we havent got to summer yet!

[native pepper]

Deciding on A/C units and their performance seems a lot like batteries, everyone has different experiences, which makes it difficult to make informed decisions. The bloke I know who has a 5kw split system in the same size and model bus runs lots of things whilst using his inverter a/c on a 2kw inverter, so will follow his example and hope it works out well.