Author Topic: Powerjack 8000W LF Inverter Question  (Read 14808 times)

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Offline Pete

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Re: Powerjack 8000W LF Inverter Question
« Reply #30 on: August 03, 2016, 04:04:02 am »
Hi Hacky, sorry I didn't get to see that post of yours until today. What you are describing sounds like what used to be called a "core balance relay".
I haven't had much to do with caravans other than to know that they have to have double pole switches and power points, that is to make sure that in the case of the lead connecting them to the mains is wired wrongly that both the active and neutral are switched off.
I run RDC's in my house and shed but I do have an earth rod and the Neutral of the inverter is earthed at the switchboards to make them work.
Older inverters would not allow the neutral to be earthed but all new complying ones do.
Also some of the older switch mode inverters also had a floating output that meant there was up to 110 volts on the neutral conductor. They were mongrels, I had an instance where a man was testing his batteries with a hydrometer and was getting small shocks off the batteries as it was raining at the time.
We fixed that by earthing the negative on the battery bank.
I will experiment  for you and get back. It may be possible to get an RCD to work by earthing the neutral at the inverter or switchboard and connecting the earth wire to the earth on the inverter. I will check it out and get back to you.

Offline Pete

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Re: Powerjack 8000W LF Inverter Question
« Reply #31 on: August 03, 2016, 08:21:06 pm »
Hello again Hacky, I tried out one of my inverters today in a stand alone situation. I connected an RCD to the output of the inverter. Then connected the earth wire to the incoming Neutral. Basically making a MEN (multiple earth neutral) system like we have in our houses.
The RCD performed fine.
So for your caravan I suggest that you try this.
Connect the inverter earth to the negative terminal of the battery.
Connect the neutral on the output side of the inverter to the Earth wire of the caravan wiring.
And see how it goes.
The inverter i used was a Chinese 1500 watt, high frequency job. All inverters built in the last decade or so should be able to run with the output neutral earthed.
I suggest that you get a multimeter or someone who has one and check that there is no voltage between the battery negative and the ground.
Just put the meter onto volts AC and put one probe into the earth, and one to the battery terminal.
Then try the same with the meter on volts DC just to check.
good luck
Pete

Offline Pete

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Re: Powerjack 8000W LF Inverter Question
« Reply #32 on: August 04, 2016, 04:41:56 am »
Hello again Hacky, just in case my description is not easy to understand here is a diagram of how to connect the RCD up to get it to work.
Basically the Residual Current Device measures the current in the Active and the Neutral Conductor. If there is a difference then that means that current is leaking to Earth or through a person. When the Neutral is Earthed as I have shown in the diagram, if any current is flowing in the Earth wire it goes back to the inverter directly and there will be an imbalance in the current the RCD measures in the Active and Neutral conductor.
Some Inverters already have the Neutral and Earth connected on the back of their power points inside, It won't matter just connect as per the diagram and the RCD should work fine. To test the RCD just put a resistor or lamp between the active and earth  of one of your power points the RCD should trip.
Hope this helps
Pete

Offline roadhse2@yahoo.com

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Re: Powerjack 8000W LF Inverter Question
« Reply #33 on: September 16, 2018, 01:13:42 am »
New Member so dumb questions will be asked...sorry

I must admit I am still confused over the neutral wire...

I have a new PJ 10000 on it's way. This will go to it's own 200a service panel and used as a stand alone power source for the majority of our household loads. Utility power will still be used for the heavier loads serviced from it's own 200a panel. I am doing it this way because I have a fairly large shop that will still require utility power for large items and with our cheap electric prices here, would simply require to much in dollars to take the whole place off grid. Our local utility does not offer a deal that makes it worthwhile to grid tie in ROI. As an example, a friend just had large system installed, no back up, at a cost of $36k, that is saving him just over $50 a month average on his bill...his ROI will never happen in his lifetime.

So we are doing this because we want to, not for any saving in dollars....But that also means I am doing it myself and being as thrifty as I can on getting setup. The basics are 5000w in panels, 935ah 24v industrial (forklift) battery, PJ 10000 LF inverter.

But this warning from PJ as to the neutral wire, "Note; Can Not L1+N+L2" seems to confuse the matter of how it is hooked into a standard service panel, at least for me. What can they mean by this? Not to hook the N into the panel is what it says to me....yet others say to go ahead. We also have bonded neutral/ground here by law in the panel if that will make a difference. The new PJ also has a stud to ground the inverter case.

So I guess what I am asking for is a yes or no on using the neutral in its normal position the same as utility service in a panel, or just a 2 wire (L1+L2) running to the panel with no neutral at all. Which then I don't understand how the circuit makes it return path to inverter.

I should add that from all pictures I have seen of these new 10k inverters, they have 1 tranny.

Yes, this is my first experience with a split phase inverter...

Sorry for the long post...

Dazed and confused in Missouri.

Offline oztules

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Re: Powerjack 8000W LF Inverter Question
« Reply #34 on: September 16, 2018, 04:04:20 am »


Your PJ will be wired the same as the street transformer, and is a center tapped winding. The center tap is the N, and the two hot winding's are your 120v just as you street one is.

So if you want 120v you can use L1 and N...... OR.... L2 and N.
If you want 240v you use L1 and L2, and ignore N.

So you can drive (theoretically) a single 10kw load@ 240v
Or, you can drive 2 seperate 5kw loads on L1,N for one, and L2 and N for the second load.
You cannot drive a single 10kw 120v load.... as you can only use a single winding for a single load.... and the transformer will be unbalanced, which will only upset the voltage set point I expect.. the winding you use will drop volts, and the unused winding will be over volt, but the over the 240v winding still 240 average.

The diagrams here will help  https://en.wikipedia.org/wiki/Split-phase_electric_power

So long story short.... yes. use fig 1 on that link, that transformer is your street transformer, which is essentially exactly the same as your PJ transformer. V1 and V2 are your L1 and L2

You cannot connect L1 with L2 together as a parallel 120v winding expecting N to be the common neutral... it will simply short the full secondary. ... hence this warning "Note; Can Not L1+N+L2"  which no one understands either,


Connection of any part of the supply should only be done at the distribution board itself, or you will create all kinds of bogies.... leave it all floating , and let the house take care of it.

 PJ N to switchboard N,
 PJ L1 to switchboard L1,
 PJ L2 to switchboard L2, and
 PJ E ( STUD) to buss bar in s/board.



................oztules
Flinders Island...... Australia

Offline roadhse2@yahoo.com

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Re: Powerjack 8000W LF Inverter Question
« Reply #35 on: September 16, 2018, 09:44:07 am »
Thank you...

That clarifies it for me and I appreciate you going over it again.

Glen

Offline solarnewbee

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Re: Powerjack 8000W LF Inverter Question
« Reply #36 on: November 13, 2019, 06:33:01 am »
Oz

I recently had my daughter wire in a receptacle to the grid and plugged in the ac input (bottom left corner flip up cover) she observed the wattage output went to zero. My goal was to keep the batteries charged on days when there is little sun ie typhoon season etc. the PJ has an internal charger and the batteries were showing 28+v at the 2 charge controllers. The PJ internal charge controller has since in the last few months gone to showing 0v but it’s not integral to the control board. I’ve never used it because it has a 36v pv input limit and I’m at 108v+ pv.

I do realize Its been awhile since you’ve messed about with a PJ but maybe something may click. Possibly it’s just their ups function and useless as a grid tie charger etc using that plug which I believe is the same as the ac input terminals. I would just tie straight to the grid if I was there full time to repair when it let out the magic smoke so an ABT is the best I can do at this point.

Adios Everbody!
SN

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Offline Pete

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Re: Powerjack 8000W LF Inverter Question
« Reply #37 on: November 23, 2019, 09:52:17 pm »
Hi Solar, I have a 5000 watt ( very optimistically rated) PJ.
Mine states on the front that it is only possible to use one of the inputs for 240 volt.
Mine has an IEC socket and also a terminal strip marked for inputs.

Mine works as a battery charger when I plug the input into my generator.
The sensing circuitry is not so accurate on the PJs. So maybe your PJ is thinking that
the batteries need charging and is in charger mode.
On mine in charger mode it has a bypass relay that clicks in that supplies power to the
house loads.
I don't think that they can be a charger and a grid exporter at the same time though.
I would suggest that you only turn the charger part on when it is needed.
Sorry can't offer more than that
Pete

Offline solarnewbee

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Re: Powerjack 8000W LF Inverter Question
« Reply #38 on: May 03, 2020, 05:20:49 am »
Hi Pete

Yeah my daughter heard the click. I know these were sold as ups also so I suppose if I had plugged it in and had the inverter output tied straight to the grid things might be different but I just remembered reading in Oz’s thread “guess who just bought” some folks having mosfets blowing up in grid ties so I just went with a mains switch I got off eBay. Inverter is tied in as mains and grid is tied in as gen so when inverter dies it dumps to grid. I’m sending out a 48v 15kw and 2 Midnite Classic 150’s to switch out, which just frightens the daughter half to death. She’s managed to repair other stuff just fine so I got faith. Today she swapped out a burned din rail 80a breaker for the front set of pv. I guess I didn’t tighten good last year and it was getting hot. 60 amps at 120vdc will do that. First time she ever had wire strippers in her hands, not bad, put my boys to shame. If they break the lock down she can get some canned air and go to town on the dust. I left the fan running since January last year. Guess I better send a new fan 😳. Was it you drew that mud map for a dump load for my windmill? That’s getting shipped this year too. Different prop tho, don’t think 111 blades is any good , 87” 3 blade might do it.

Take care!
SN

Any day above ground is a day for potential mishaps

Offline Pete

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Re: Powerjack 8000W LF Inverter Question
« Reply #39 on: May 03, 2020, 09:27:30 pm »
Hi Solar yep it was me that drew the Delta diagram for you windmill.
Make sure that all the circuit breaker connections are very tight. It makes a mess when there are high resistance joints at high current joints.
120 volts and 60 amps is fairly hefty. I hope you are using DC rated breakers at that voltage?
Cheers
Pete

Offline solarnewbee

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Re: Powerjack 8000W LF Inverter Question
« Reply #40 on: October 20, 2020, 10:54:46 am »
Hi Pete!

Yep, all breakers are DC rated and still had one burn where the front roof set comes into that breaker. Probably I didn’t double check tightness. I really should take my inch pound torque wrench with me. I have a book around here give all the required in/lbs every electrical fitting instance. I prefer breaker with a square or hex socket screw but the breaker I prefer don’t have them.

I just recently found out my charge controllers were not set to the correct absorption stop level. It hasn’t been charging them full. Suddenly the charging amps jumped from 32 to 45. I’ll be happier when my Midnite Solar controllers get there and I can monitor and program from stateside. Did you upgrade to 24v yet? I shipped a 48v 15kw PowerJack and have to find a local buyer to take this 100lb 24v PowerJack  beast off my hands.

Best Regards.
SN

Any day above ground is a day for potential mishaps

Offline Pete

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Re: Powerjack 8000W LF Inverter Question
« Reply #41 on: October 21, 2020, 06:03:23 pm »
Hi Solar, well on the issue of tightening connections, with large multi strand cables I tighten them initially, then wriggle the cable about a bit then re tighten them. I usually check them again after a while too. Then do tend to loosen.
Some come with a metal ferule that goes around the cable and they seem to help to stop the strands from separating but still tightening a few times helps.
I did manage to go over to 24 volt, I bought a 24 to 240 volt 50hz Upower inverter. It must be a powerjack clone as it is exactly the same inside.
It came with a loose screw rattling about from the mosfet board. Then I found it had the neutral and active transposed on the output and one of the plugs was half out on the control board. Also there was an output board floating above the transformer that had shorted out onto the transformer mounting bracket. Fortunately the inverter survived until I found the faults and fixed them.
Pretty good inverters just need to be checked out before using and problems fixed.
So far it is going great. I can now run my air compressor and wood splitter directly off my solar. I only have to fire the generator up to do welding which I dont' do a lot of.
Is your 24 volt inverter 230/240 50hz output? and what size.
Pete

Offline solarnewbee

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Re: Powerjack 8000W LF Inverter Question
« Reply #42 on: October 21, 2020, 09:43:34 pm »
Hey Pete

Good to hear about your new inverter. The old inverter is 110/240 60hz 15kw (I only use the 240) I think the hertz is adjustable on this model. New inverter has push buttons to change voltages and hertz. The old one has DS18B20 temp sensors on everything. Glued on with thermal adhesive. Had a Rpi displaying temps. New inverter rarely gets warmed up unless you exceed 2000 watts and that’s just the coil. Heatsinks always feel cool to the touch.

All the best
SN

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