Author Topic: Just bought a powerjack 15000, modding.  (Read 2644 times)

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Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #15 on: November 16, 2016, 06:47:29 AM »
Hi Welshman, the easiest way to tie the Earth to the Neutral is at your switchboard on the house. There is usually a neutral bar and an earth bar, a short wire is run between the two. RCD's or RCBO's are usually mounted on the switchboard for ease of use.
If you want to do it at the inverter, just leave all the inverter internal connections as they are, and connect the neutral to the earth at the output terminal block. Just a short loop of wire will do.
I always connect the case of the inverter to earth as well. A wire directly from the case to the earth terminal on the switchboard or to the earth rod.
cheerio
Pete

thanks for the reply pete.

I have tested the continuity of the earth on the control board to any other point , ac/dc and there is no continuity. removing the control board from the heat sinks I had a look at the traces on the pcb's and found the earth only joins to anything via these capacitors.

if I join the neutral and earth it is essentially shorting both the caps. is that going to be a problem?




Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #16 on: November 16, 2016, 07:27:03 AM »
some images of the resister values


Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #17 on: November 16, 2016, 03:13:17 PM »
it's new housing and fans have arrived. 600x600x300 ip65 enclosure and a set of 240v fans on a rack. next job cut out the enclosure.


Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #18 on: November 16, 2016, 03:41:43 PM »
one thing i have noticed, although the build quality is ok to good. there is metal filings loose everywhere in the casing, there is also a lot of left over flux all over the boards and you can see which modifications are made by someone else as they are not using enough heat to solder and its causing the solder to ball instead of sink into the metal. based on this anyone buying one of these should thoroughly wash the boards and inside of the metal casing as some of those bits of metal were up to 3-4mm long and freely floating about in the case could one day or day 1 cause a short or worse.

it looks like they add a capacitor and a resistor to the fet boards and a couple of resistors to the control board, you can clearly see the difference in soldering.

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #19 on: November 17, 2016, 10:44:01 AM »
first test fit for marking out holes etc, plenty of airflow is the plan.

Offline Pete

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Re: Just bought a powerjack 15000, modding.
« Reply #20 on: November 17, 2016, 03:17:08 PM »
Hello Welshman, first the bonding of the neutral to earth is done on the output side of the transformer. That is the 230 volt side. You can make the connection by connecting the neutral and earth at the RCBO. Just bring out the active, neutral and earth wires to the RCBO, connect the neutral and active as usual to the breaker, then on the output side of the breaker connect the earth and neutral.
The earth continues on to all the earth connections in the house or wherever you are supplying power to.
The Active and neutral likewise.
I would not change any connections inside the  inverter.
I have two PowerStar W7 inverters they are both connected to an MEN system in my shed and house. I have just connected the earth bar to the neutral bar in my swithboards , all works well.
You need to remember that the control board in the inverter is on the low voltage side of the transformer, so are the Mosfets. The inverter circuits basically turn the DC from the batteries into an AC waveform to drive the primary (low voltage side) of the inverter. The secondary (high voltage) side is connected to the loads.
As Frackers pointed out a fault on the output side of the inverter should not be able to feed back through the transformer to the battery side.
Keep all Modifications such as connecting the earth and neutral and connecting the RCBO to the high voltage AC side of the inverter.  Either to the Output terminals or on your house switchboard.

Offline Pete

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Re: Just bought a powerjack 15000, modding.
« Reply #21 on: November 17, 2016, 03:36:10 PM »
Welshman I put a diagram on a post to anther member about a powerjack, if you look at the posts about the 8000watt powerjack you will see the diagram at the end of the posts.
http://www.anotherpower.com/board/index.php/topic,1091.30.html
hope this helps
Pete

Offline sunnypower46

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Re: Just bought a powerjack 15000, modding.
« Reply #22 on: November 17, 2016, 07:38:45 PM »
Was wondering if anyone has tried improving airflow for the toroid(s) by removing the top/bottom hold down discs, turning the toroid on its side and literally blowing air through and around the thing?

Seems inefficient to bottle up all the heat in the core when a different mounting arrangement could be tried.  I figure PowerJack chose that mounting arrangement as a mechanically secure shipping method.  Not worrying about that once it's arrived, maybe there's a better way.  From what I've read on this site, toroid heat is what is holding back the continuous power output of these units.

At some point I'd like to try that with my PJ 8000 LF SP, unless someone can convince me that's a really stupid idea and a waste of my time.  Any takers?




Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #23 on: November 18, 2016, 05:44:06 AM »
Was wondering if anyone has tried improving airflow for the toroid(s) by removing the top/bottom hold down discs, turning the toroid on its side and literally blowing air through and around the thing?

Seems inefficient to bottle up all the heat in the core when a different mounting arrangement could be tried.  I figure PowerJack chose that mounting arrangement as a mechanically secure shipping method.  Not worrying about that once it's arrived, maybe there's a better way.  From what I've read on this site, toroid heat is what is holding back the continuous power output of these units.

At some point I'd like to try that with my PJ 8000 LF SP, unless someone can convince me that's a really stupid idea and a waste of my time.  Any takers?

ill look into mounting them from the ceiling of the unit with something that can clamp around it and through the hole. metal strap with some rubber lining, a juiblee clamp perhaps, it might make them vibrate a little? and what happens when you place a looped wire or metal bar around the toroid how does this effect the currents?

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #24 on: November 18, 2016, 05:49:17 AM »
I wonder why transformers dont incorporate any cooling factors into their design, is it simply if it's too hot it's not big enough mentality? (or easier just to house them in oil?) what about a ring style heatsink to go around the edge of the toroid providing cooling fins for it? would that be a problem with the magnetic currents?

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #25 on: November 18, 2016, 06:33:43 AM »
Was wondering if anyone has tried improving airflow for the toroid(s) by removing the top/bottom hold down discs, turning the toroid on its side and literally blowing air through and around the thing?

Seems inefficient to bottle up all the heat in the core when a different mounting arrangement could be tried.  I figure PowerJack chose that mounting arrangement as a mechanically secure shipping method.  Not worrying about that once it's arrived, maybe there's a better way.  From what I've read on this site, toroid heat is what is holding back the continuous power output of these units.

At some point I'd like to try that with my PJ 8000 LF SP, unless someone can convince me that's a really stupid idea and a waste of my time.  Any takers?

since you have a pj 8000 it would be interesting to see what the difference of the adjust resistor on the controll board. mine has a smd with "1000" on it which translates into 100 ohms.


Offline Pete

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Re: Just bought a powerjack 15000, modding.
« Reply #26 on: November 18, 2016, 02:32:16 PM »
Welshman, I would be very careful with the idea of hanging the torroids from a metal bracket. You may be just adding a secondary winding of one turn . In other words a giant high current secondary closed loop. The Eddy currents flowing in the bracket would be enormous.
As to trying to get more power from the inverter by cooling the transformer, I am not sure why you need more than 15kw. If you do then you would need to add another set of driver transistors and also another transformer in parallel.
Probably easier and cheaper to buy another inverter and split your loads across the two inverters.
Just wire the buildings up with multiple power circuits and split the loads evenly.
It would be cheaper than blowing up a perfectly good inverter trying to squeeze a few more watts out of it. And also add a level of reliability, that is if one inverter died and needed repairs at least you would have the other one.
Generally the main limiting factor on inverters is the battery bank size and capacity. Plus whatever charging equipment you have.
Remember that you have to put in more than you take out. The old no free lunches part.
Best to keep it as simple as possible, that is my way of looking at renewable energy.

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #27 on: November 18, 2016, 03:08:30 PM »
Welshman, I would be very careful with the idea of hanging the torroids from a metal bracket. You may be just adding a secondary winding of one turn . In other words a giant high current secondary closed loop. The Eddy currents flowing in the bracket would be enormous.
As to trying to get more power from the inverter by cooling the transformer, I am not sure why you need more than 15kw. If you do then you would need to add another set of driver transistors and also another transformer in parallel.
Probably easier and cheaper to buy another inverter and split your loads across the two inverters.
Just wire the buildings up with multiple power circuits and split the loads evenly.
It would be cheaper than blowing up a perfectly good inverter trying to squeeze a few more watts out of it. And also add a level of reliability, that is if one inverter died and needed repairs at least you would have the other one.
Generally the main limiting factor on inverters is the battery bank size and capacity. Plus whatever charging equipment you have.
Remember that you have to put in more than you take out. The old no free lunches part.
Best to keep it as simple as possible, that is my way of looking at renewable energy.

that's the kind of thing i was thinking, so one loop of metal would be like shorting the transformer. best it be a nylon cargo tie strap or something similar.

the idea here is not going for big power, just aiming to get a decent amount for continuous time greater than the original spec of the powerjack as it is in its tiny box, which will probably mean over riding the limits of current detection.

edit - i want it to do 230 v @ 40 amps for an hour, which would equate to  9.2kw output and 238amps at dc 48v with an 80% efficiency in the system.

my batteries are 520 a/h in total, if i can get 40% out of that i will be coming close to the goal, if i can't ill double the battery bank to give extra time.

the system will be slow charged at low output of the inverter by wind turbine and at high current when over 150a is taken from battery or when a critical point is reached of low voltage of the battery bank then the generator kicks in and does a full charge.


that might just be pipe dreams in practice. but as close to that

Offline sunnypower46

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Re: Just bought a powerjack 15000, modding.
« Reply #28 on: November 18, 2016, 09:05:22 PM »
Welshman, I agree with Pete re using a metal strap.  Not a good idea.  Need to use something non-metallic.

Your 9.2KW continuous goal may be tough without special cooling.  The continuous power output of PJs is known to be highly overrated.  The toroid heats up quickly and the attached thermistor will shut the unit down.  If you can open up the toroids and improve the airflow, you may have shot at 9.2KW.  Otherwise, 35-40% of PJs stated power output is what you should expect (continuous). 

At 3KW, my PJ 8000 (24v) toroid is very hot to the touch.  Granted, you're running 48v so current should be half what runs through my single toroid, and heat will be further divided by your two toroids.  So, maybe you've got a reasonable shot at it.

A note about the batteries.  My PJ holds output AC voltage quite good.  But, as the battery voltage drops, DC current must increase to deliver the wattage.  As the amps go up, battery internal resistance increases and the system works harder to meet your needs.  And the battery voltage drops faster and faster toward auto shutdown.

I'll try and find the "adjust resistor" on mine this weekend.  I'm not sure our control boards are exactly the same.

Offline ClockmanFrance

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Re: Just bought a powerjack 15000, modding.
« Reply #29 on: November 19, 2016, 02:49:47 AM »
Sunnypower46.

Cooling toroid, OzInverter.

As you can see from the photo with this normal 6kW 30kg toroid, 48vdc to 230vac, the Primary turns are 50mm/2 about 12mm in diameter.

This then gives a good 10mm airflow around the secondary and through the centre hole, without having to drill or alter the holding disk and clamp rubbers.

I trust this helps.

And.....  https://youtu.be/C3If9sbpdcA