guess who bought a power jack inverter

[lighthunter]

I forgot to mention some of you may wonder how well loads like to switch power sources while they are running.

As of lately none of the appliances connected to the solar are complaining at all. 2 freezers and 2 fridges are able to switch without any notice when standing next to them. If you listen closely you can tell when it switch6es but the motors continue running.  The switching occurs within 1 cycle of the 60hz waveform so not much time is lost, around 15 milliseconds if I remember right. Air conditioners are the only load I had trouble switching, They would loose too much speed and trip out during the switch since the rotors are loaded quite heavily.

There are several solutions to this problem which I will correct but for now if I want an air conditioner to run I simply turn the utility breaker off for that  load and the AC unit starts and stops as the solar power is available to run it.  Later, I will sample the wave form from each source and switch when they are synchronized, if this doesn't solve it I will add another relay to the problem load and program a power off for a couple minutes before re-energizing load. Of course, if it has a digital display temp setting, a capacitor would need to be added to circuit board of AC unit to hold settings during off period.

I had a lot of fun working with this and is very rewarding, I'm hoping for an 8 year payoff but if not then it was still fun.

[oztules]

The guardian switch is cool.

Zero crossing is not good to start a transformer, better to start it at the top of the waveform if you can..... syncing the signals is a good idea.

Really your having a disproportionate amount of fun for a 2 battery system.



......oztules

[frackers]

Has anyone put a remote control facility onto one of the Power Jack inverters? I'll be getting a 8000W LF but my current (mod sine) inverter I switch on/off with my controller as the system is really just for emergencies.

At the moment I simulate a push button (with a relay) and monitor for an LED to be lit (i.e. use an opto) to say the inverter is on. Would be handy to duplicate this on a pure sine box.

Cheers

[oztules]

"At the moment I simulate a push button (with a relay) and monitor for an LED to be lit (i.e. use an opto) to say the inverter is on."

That will work fine... it needs to be held on for the duration. it won't self latch without mods.... and I am guessing your does this at the moment too.

...............oztules

[lighthunter]

Ok i happend on the specs of a 2.5kw inspire inverter. Very impressive. The ideal dc downconverter plus mppt function. Thats nice! If i make my own buck converter to do 250 plus down to 48 theres bound to be a lot of time and some smoke involved.  If i ran hv dc buss from slr panel  back to house the inspire could be inside and do the mppt function and supply ac loads.

Only cons are there arent many available and none that ship to US. One other item is they are 220, could rewind for 120v or change evrything in house to 220v. PJ would b basically out of a job except for battery charge and load fill in. Brilliant setup Oztules.

[oztules]

Yes you could transmit at 350-400vdc to the house.

The grid tie will do the mppt, but it has to have the power jack supply the grid frequency, it is not stand alone.... none are.
The powerjack will need the small inductor conversion, or they don't play well... at all.

Then yes, it will power the house loads for as long as the solar is more than the house drain, then it will use battery when solar is less than drain, and charge the batteries if above drain, and run house..... mine does this every day.... it's neat........... need a dump load or voltage switch to monitor the grid tie unit, it can't throttle back, so will try to cook the battery if it has too.

I assume there are 110v units over there somewhere.


.....oztules

[steve3]

Hi Oztules Thanks very much for pointing me in the right direction for getting the ferrite cores, they should be here soon.
Lets see if I have got things right please,

Isolate the mains from my grid tie inverter,
With the choke fitted power up the 8000 w Lf.
This will wake up my sonny boy 3600w inverter grid tie
Any excess power from the PV will go through the 8000w LF inverter
and charge the batteries , but do don't over charge them,

(1) Have I got hold of the right end of the stick
(2) Would 4 turns be better than 3.5 ? on the choke ?
(3) What mods have you in your head for reading Dc power
from inside the 8000 w LF

Your help is invaluable to us all, many many thanks Oztules, Steve.

[oztules]

1. yes
2. marginally better... not worth it if is too hard to fit the extra 1/2 turn in.
3. I use one of these http://www.ebay.com.au/itm/DC-0-120V-0-250A-Voltage-Current-Capacity-Watt-Battery-Monitor-State-of-Charge-/181295595016?pt=AU_B_I_Electrical_Test_Equipment&hash=item2a360f3e08     
It is not the best unit in the world, but once calibrated does kwh kw V A AH and percentage of charge left.

Beware, if you fit the zener in over the "cut if high" resistor, it will not turn off on over voltage... after about 64v it may go poof if your 3kw of grid gets the batteries charged up, and the sun comes out. You need a way to stop it, or dump the excess.

If you don't use the zener, the PJ will shut down the grid tie and itself at 62v or so.... it will require a restart to continue.

The power jack becomes the grid to the grid tie by connecting the grid tie to the output of the powerjack...... do not attempt to get the mains involved in any way with it like this..... keep it entirely separate.

NOTE:

 I have never tried to use a HF grid tie unit for anything... not even normal grid tie.... I use the heavy galvanically isolated things that weigh a  ton.
I expect the transformerless units to work the same, as they don't know the difference between the real grid, and the PJ grid.... but I have not used a transformerless one myself... never will either, have too many of the heavy ones to use.


....oztules

[lighthunter]

Oztules, Thankyou for ideas on long distance power efficiency!! Very helpful information!
Have a great day! 

Lighthunter.

Ps ...do you have any idea if the inspire you have can sync to 60hz or would that b out of range? Im not asking u to blow anything up checking, just thought it might b in the specs. Thanks!

[oztules]

Any approved grid tie unit in Aust will run from 49.5 - 50.5 hz.... no more no less.

It is part of the AS4777 that there is only 1 hz of movement  ( 50+/- 1/2 hz) before shut down occurs.... and no restart until stable hz and volts has occurred for a period of time within that window.

Now thats what I am told is in the regulations, and my grid ties agree..... but of course the regs that you must follow are NOT available for perusal...nor can you get a copy to read them...........without big fees up front........ typical Govt idea.


..................oztules

[lighthunter]

Makes sense... I had to ask because i had found these specs of a different inverter but same manufacturer.  I suppose it is in a different class tho with different regulations. Thanks again for info i owe you!

Technical Parameters:

EHE-N50K Model EHE-N50K DC Input Max. DC Voltage 880Vdc MPP Voltage Range 420-820Vdc Max. DC Power 55KWp Max. Input Current 125A AC Output Output power 50KW Current THD <3%(?50%rated power? Nominal Grid Voltage 320-450Vac Nominal Grid Frequncy 50/60Hz Power Factor .?0.99??50%rated power? System Max. Efficiency 95% Euro Efficiency 94% Protection Degree IP20 (indoor) Operating Temp. -20~+45? Cooling Humidity Controlled forced-air cooling Relative Humidity 15%~95%, non-condensing Comm. Interfaces RS485/RS232/Ethern/GPRS Display LCD Mechanical Data W | H | D 800/2200/800(mm) Weight 700kg

[steve3]

Hi Oztules Thanks for the answers to questions 1 2 3 above, you stated the grid tie inverter will not know the difference between the real grid or PJ, everything seem the say that is very true seems to run anything. After running on the PJ for a few nights testing, the TV. died a sudden death, leaves me guessing was the TV. due to die anyway or is there something in the PJ it don't like, it’s a modern 40 inch flat screen job, your views will be much appreciated, many thanks for all your words of wisdom. Steve.

[oztules]

1. The PJ output is a very convincing sine wave, and it's regulation is tight... so I don't suspect it for a second.
2. The TV will have a pwm, pfc corrected input, so can stand very large voltage swings without damage.
3. Due to the pwm power supply, the guts of the telly will be well protected from nearly any weird input short of lightning strike..... however, this is also the Achilles heal of them.... the caps die from ripple in most instances, and replacing these will usually get the thing running again...... but sometimes the power fet dies as well from trying to compensate too hard, and it and it's driver will need a makeover too.

In all the flatscreen tv's I have fixed over here, it is always the power supply shot...... eg: try this... http://www.anotherpower.com/board/index.php/topic,302.0.html


............oztules

[Wolvenar]

I just wrote up a quick post about one of the repairs I have done on these LCD power supplies.
I didn't have to get as down and dirty in the repair as Oztules, hope it may help a bit as well.
http://www.anotherpower.com/board/index.php/topic,961.msg9338/topicseen.html#new

[lanyho]

Hi Oztules.

I finally got to set the overvoltage protection  in my PJ5000W LF. I used a zener diode as you wrote.
[ Specified attachment is not available ]
 I got only Uz = 3,9V, but it did not work. The voltage of about 4V at resistance marked "CUT if LOW" is so sensitive that the soldered diode voltage dropped to about 2V and the inverter was not running. You correctly point me toward. I replaced the resistor (10M) for about 800 k and on-chip voltage dropped from 4,1V to 3.7V.
[ Specified attachment is not available ]
Overload protection is already ok

Thanks again

by the way, you do not know what's the second voltage labeled "CUT if HIGH " about 7.5V?
Resistance at this point is missing.