A tale of two inverters

[wpowokal]

Regulars may remember that I retired to Far North Queensland Australia (FNQ) to a place called Cow Bay, that being north of the Daintree river http://www.youtube.com/watch?v=Bz0IHLN_A-4 and that makes us "isolated". Not that it is far to the nearest town, just an hours drive but to have a trade person out is like $200 OZ each way then time on the job. So we all help each other, here begins my tale, my good mate works away quite a lot and he and wife, like me rely on renewable energy.

It began with a call from said wife one splendid FNQ day, telling me the inverter had failed, so across the mountain range I drove to confirm upon arrival that some of the Mosfets were zapped.



 As I had taken the precaution of taking my spare 3Kw 24v inverter with me I reconfigured the batteries to 24V from 48V, installed my inverter and she had power again.

So being a bit short of the ready ($$$$$) my mate purchased http://www.ebay.com/itm/4000w-8000w-pure-sine-wave-SOLAR-inverter-48v-50A-battery-charger-LCD-220v-/140723696831?ssPageName=ADME:X:AAQ:US:1123
This inverter was obtained for a very good price and at first glance seemed a good buy, however it lacks the sophistication we are used to in OZ made equipment, however the seller  was very accommodating. He sent a 50A? charger free of all costs since the inverter could be an inverter plus solar regulator OR inverter and charger.  We were able to hack into his site to obtain information about re-programming said inverter.

Little by little the inverter was re programmed to suit site conditions, the charger arrived,


It worked well as a <25Amp charger, so much for it being a 50 Amp charger, we did later up the amps but it got hot so returned it to original setting.
There is much more to this story but ATM I am unable to insert more than one pic, which seriously detracts from the intended tale so I give up and will try again another day.

Allan of the jungle

[wpowokal]

I am cursed, even in a reply I can post only one pic!

[Frank S]

Mate your not cursed. when you attach a pic look just under where it says choose file  you should see in ( more attachments) select that  each time for more pics and to the right  select where you want them to appear  usually will be inline expandable  thumbnail
 hope it helps Cheers

[wpowokal]

Thanks Frank, I will try again starting with the pics that should have been in the first post.

This being the business end of the old inverter, an OZ made unit built like a brick outhouse and the predecessor of the unit I am used to.

This being the repairs I had to make to the charger, on one of my trips over the mountain said wife told me, over the mandatory cup of tea, that the charger had also stopped working. Upon investigation we( I say we because she did the work under my watchful eye)  discovered that the 240V socket was U/S, OK but what was very disturbing was the earth pin was connected to diddly squat, now for an all metal case this was a worry. But as you can see from the pic, hard wiring worked a treat.

The new inverter, as value for money I give this a big tick, and the seller an enormous tick.

The connection area of the inverter.

What makes the new inverter work.

To allow the new inverter to work as a inverter/charger ( the 50 amp charger was a miserable failure) albeit at only 6 amps. He purchased a cheep Chinese solar regulator which works a treat, it replaced the PL60 that had gone somewhat troppo.

A relic of the past, a perfectly good but fuel hungry gas (LPG) gen set.
I am pleased to say all is operating as well a a cheep inverter can, there is another uncompleted task at my mates place, which concerns the refurbishment of a Chinese diesel gen set, but ATM that must wait as I feel the need to take my dog for a swim at Cow Bay beach.

Our tropical waters are very warm ATM and very enjoyable.
I have also been busy developing my own separate 12 V system, separate that is from my 48 volt system, but more on that later. Oh and if you ask nicely I may include a few pics of a recent trip to the Great Barrier Reef, absolutely nothing to do with renewable energy but just to get you drooling a bit.

Allan of tropical Far North Queensland OZ

[Frank S]

I have the same PWM only I have the CM6024Z model
 I won't say it's the bee's knees but I have seen it do 72 Amps for a short short.  One thing I did was use standoff studs to mount mine with a 1 inch air gap behind it. This greatly reduces it's heat build up
   I'm feeding it with  #2AWG THHN stranded, and it feeds the the batteries with the same ga wire  with a centeral connection point for it, the  Schumaker 60/30 the 500MCM to the 3000w inverter, and the 000 for the small 1800w inverter, and the batteries all converge

[wpowokal]

During the above trials and tribulations, specifically when the inverter would not act as a charger with greater than 6 amps, and still does not.

I cobbled together this beast...



It utilities a transformer out of a dead inverter, but the charge current was not enough so I placed a auto transformer in line to boost the primary volts to 300, that made it sit up and dance. It was housed inn a locked cabinet so never made it to being self enclosed.

Still having fun in the jungle.

Allan

[wpowokal]

OK another part of this tale involves a 5Kva diesel genset of Chinese origin, a wiz bang silenced model that failed after 9 hours service.



Uncovered it looks like this...



With a temporary fuel tank connected the motor started easily, well it took quite a lot of battery power ..



My trusty ute was used to supply this battery grunt, and start it did, but alas no terminal volts from the generator, even after flashing the 12V charging circuit. So digging a little deeper I uncovered the excitation capacitor that look very suspect, and yes at ...



A fraction of the rated capacitance at least one problem was found, and duly replaced with a metal can capacitor, in a different position so it was not immediately adjacent to the exhaust muffler.

This time flashing the field apparently did not help but loading it did and we had power...



We still have some wiring to sort out, as found all wires disappeared into a potted black box, I am rewiring it to basic protection and stop start. But suffice to say a genset that had been pushed into a corner for 9 years is now a functional unit.

[oztules]

Good to see your still doing good up there.

I find it hard to get excited about HF inverters, and apart from the low idle currents, can't find too much to be pleased about.
The other problem is you can't reverse feed them, and so need big solar chargers, when a cheap grid tie inverter will do just as well, and run the house during the day, easing the loads on the inverter

You can get the idling currents down on the LF models if you try though.

Something like this project. http://www.anotherpower.com/board/index.php?topic=780.0  Gets the best of all worlds, and I can recommend it against abuse..... including putting the output into the input ( it's a UPS too) ... makes an unseemly noise, but shuts off without death... on more than one occasion..... ( not too bright here).

Have seen it reverse feed 80 amps into the battery bank  (48v) while fiddling with it and my solar arrays... from over 4kw of solar into three grid tie inverters..... yep were as mad down here as those gone troppo up there. It has enormous start up power too.... ie 9 inch grinder starts instantly.... no wind up at all.

They are also cheap as nuts too.

The regulators for that genset are available on aliexpress and ebay for very little money too.


.......oztules

[wpowokal]

Hi Tules, thanks for your response, interesting project you pointed to, unfortunately I lack your background so it is more rip tare bust for me, all the time hoping something works, generally just applying basic principles all the time hoping to solve the problem.

Allan of FNQ hoping for rain 

[domi]

Allan of Wokolup,

Good to fall into one of your tales of abject misery again! Interesting read! What are you growing up there, any plantation? Have you got a mill there?

dominic