Inverter(s) tripping

[BritishPete]

I am new here but I have just discovered the "Ignore button" It is a wonderful tool.

[russ]

Whatever with the "should s" THREE inverters do the same AND most inverters are good to only 15.5V sometimes 15V

I really think it best I ignore your posts in future.

Mod note - New and obnoxious? Careful - I have a bigger ignore button

[BritishPete]

If anyone could show me a reasonably priced inverter that won't trip at 15.5V I would buy it.

PS. I worked in the Attaturk area for a while I enjoyed the food.

[billvon]

Normally it is fine but when a charge controller changes to ABSORB the current also soon dimishes. When fast moving cloud changes MPPT voltage from say 14V to 14.8V at reduced charging current it will often overshoot for a fraction of a second. My Flexmax 80A (Australian) controller frequently records 16V and in this situation enough to trip all 3 of my inverters. Also 15.5V is required (for most flooded battery banks) to equalize. this will trip just about any inverter.

Hmm, odd. The 12V inverters I have experience with:

Trace SW series DC voltage 11.8 to 16.5V
Prosine 2.0 10-16V
Outback FX2012 10.5-17.5V
Xantrex Freedom SW 3012 10-16V

But I suppose some inverters might have trouble.

There is a simple fix (thanks for asking) Installing a Silicon diode between the battery bank and the inverter(s) will drop the voltage at the inverter(s) by 0.7V.

Wouldn't work for any of my installations. For a 2000 watt load that's a loss of 140 watts in the diode. That's more cost, power loss and heat than I'd want to try to deal with in a system designed for long term operation. But for smaller systems it might be a simple fix for an inverter problem.

[BritishPete]

Mine; Power max TSW 15.5V
Aims 15.5V
Vector 15.5V

All trip above 15.5V for more than a second or so.

The inefficiency in my 1600w system is not really a problem as it is used only a total of about 5% use time so the 5% loss becomes 5% of 5%.

[BritishPete]

Russ, I am impressed you did leave my comment, so in fairness to all I removed it.

[john p]

many of the cheaper 12v inverters do trip at about 15 to 15.5 v especially TSW ones. Most but not all quality 12v inverters dont trip below 16.5v

[Sunking]

Anyway your loss I had much to offer but cannot deal with arrogance.

It is not arrogance, it is experience. Between John P and myself we have over 70 years combined electrical design and technical experience. Throw Mike, Russ, and Rich into the equation and we have over 100+ years of experience

So far you have not added any value. You lack basic knowledge and design concepts of solar power systems. So far you have given bad advice which is why you are rebutted. Those with experience are not going to allow you to get away with it. One example is you do not know the difference between a watt and watt hour., or how to calculate either value. watts and watt hours are two of the most important specs in an electrical system and if you do not completely understand that you have no biz giving advice.

[BritishPete]

Good to know, of course I am stuck with mine now but one day I might just upgrade to a 24V or 48V system, that would be the time.

[john p]

Britishpete really a diode is not the answer to solving the overvoltage problem, The losses are great unless you are going to be manually switching it in and out of circuit. That is a pain.And you are making the inverter draw more current than usual .Lower input voltage must draw more current than higher voltage for a given output wattage.

Think about getting an adjustable controller. then set it to 15v. its a cheaper solution than going to 24v ,unless you intend to vastly increase the system size. 12v has advantages. there are more easily obtainable devices than 24v ones.

The only time I think people should have a diode in the input side of the inverter is to fool the inverter to shut down sooner than they usually do. Nearly all 12v inverters have a low voltage shutdown of between 10.5 and 11v . Far to low to save the battery. But this really is a design fault of the inverter .While it would help that problem ,it creates its own problems.

Also remember what Sunking said. Dont ever give a statement like "it uses 180w". You always need to use watt hrs. ie 180whr. Think about how your grid meter reads power ie 1080kwh..

[BritishPete]

Britishpete really a diode is not the answer to solving the overvoltage problem, The losses are great unless you are going to be manually switching it in and out of circuit. That is a pain.And you are making the inverter draw more current than usual .Lower input voltage must draw more current than higher voltage for a given output wattage.

Think about getting an adjustable controller. then set it to 15v. its a cheaper solution than going to 24v ,unless you intend to vastly increase the system size. 12v has advantages. there are more easily obtainable devices than 24v ones.

The only time I think people should have a diode in the input side of the inverter is to fool the inverter to shut down sooner than they usually do. Nearly all 12v inverters have a low voltage shutdown of between 10.5 and 11v . Far to low to save the battery. But this really is a design fault of the inverter .While it would help that problem ,it creates its own problems.

Also remember what Sunking said. Dont ever give a statement like "it uses 180w". You always need to use watt hrs. ie 180whr. Think about how your grid meter reads power ie 1080kwh..

Actually I have a controller with multiple variable user parameters including shut down at user defined voltage (mine is set to 11.8V with reconnect at 12.1V) BUT I think you are missing my point; In order to fully charge the batteries within sunlight hours I need more than 14.8 volts once a week. There is no jumping up and down I just put the diode in circuit for 2 hours once a week. Losses are really irrelevant as the power would otherwise not be flowing to the batteries anyway once they are on absorb for an hour or two. So I wait until charging current falls off to about 20 amps (on a 1000AH bank) then increase voltage to increase charge amps to 30A (decreasing) for the last 2 hours.

For me it works perfectly, and is very little hassle.

[BritishPete]

Ref yourt last, this is what I wrote;

Convert a chest freezer! I did and use only 180W per day average.

Now technically I included a time base (day) so this now becomes a measurement of total power (energy consumed in 24 hours). 180 watts per day or 180Whrs per day = same thing.

Without a DAY or HOUR or whatever other time base I agree I would have been incorrect.

[Sunking]

Now technically I included a time base (day) so this now becomes a measurement of total power (energy consumed in 24 hours). 180 watts per day or 180Whrs per day = same thing.

I rest my case you do not know the difference between watts and watt hours. They are not the same thing.

Watts = Power = Voltage x Amps
Watt Hours = Energy Consumed or delivered = Watts X Hours = Volts x Amps x Hours

Huge difference.

[billvon]

Ref yourt last, this is what I wrote;

Convert a chest freezer! I did and use only 180W per day average

Now technically I included a time base (day) so this now becomes a measurement of total power (energy consumed in 24 hours). 180 watts per day or 180Whrs per day = same thing. [/QUOTE]

180 watts average per day is 4.3 kilowatt-hours per day. This is a pretty common question in PV - "how many kilowatt-hours will I need if I use 100 watts a day average?" 100 watts is power; the answer they want is 2.4 kilowatt-hours per day, which is a measure of energy.

[Mike90250]

....180 watts average per day is 4.3 kilowatt-hours per day. ...

Darn big freexer to pull that much ! I could run 4, full size fridges for that power.