Author Topic: Just bought a powerjack 15000, modding.  (Read 2643 times)

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Offline sunnypower46

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Re: Just bought a powerjack 15000, modding.
« Reply #30 on: November 19, 2016, 10:00:47 AM »
>ClockmanFrance:  Nice!  The photo and video were very enlightening.

Reading between the lines (er: pixels), it appears the extremely heavy gauge primary wire opens up an airway at the top and bottom of the toroid.  So, I expect a non-metallic spacer of sorts would achieve the same effect.  Directing airflow around and through the toroid with strategically placed deflectors would be worth trying.  That's seems easy enough to try when I can find some extra time.

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #31 on: November 19, 2016, 01:00:16 PM »
having some billet aluminium milled into bracket/busbar to mount the heatsink parallel with the board. this will allow me to connect the feed to the toroids direclty to the busbar and use thermal compound on the heatsink backface, which i know will make a significant difference in cooling alone, coupled with the change in angle of the heatsink with air being blown directly down onto them should keep them nice and cool.

also in process of stitching some thick seatbelt type material used for cargo straps in a loop around the toroids for mounting them, or rather hanging, from the ceiling as inspired by sunnypower46.

also c101 copper busbar ordered, thankfully got it at trade price through local fabricator. inch and qtr by qtr , 6 metres of.

i found this useful for bar sizing based on current

https://www.copper.org/applications/electrical/busbar/busbar_ampacities.html

and this useful for wire sizing.

http://www.engineeringtoolbox.com/wire-gauges-d_419.html

i got a piece of id 37mm tube turned down on the outside to slide into a scaffold tube to mount the istabreeze 2kw wind turbine on.

besides that had a tinker with some of the voltage sensors and relay timers, all seems to be straight forward.

waiting on a couple of bits and pieces but i can start work on the sensing circuits and gen control stuff.





Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #32 on: November 19, 2016, 01:54:19 PM »
does anyone object to setting up a bank of batteries like this on the left instead of right?

it should provide the ability for slow charging cells to be not stressed or be an impedence by providing another path for the other cells/battery in series with said cell to carry their current.

it should also provide better equalisation and faster charging.


Offline Pete

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Re: Just bought a powerjack 15000, modding.
« Reply #33 on: November 19, 2016, 03:25:50 PM »
Hi Welshman I am not a battery expert but the idea you have of paralleling up each 12 volt section seems like it would work. The main thing that I could see as a problem with it, is if one battery or cell dies or goes short circuit then all the preceding batteries will drain into it. You could end up with 4 times the short circuit current or alternately all the battery strings drained flat at once.
That one may be worth looking into a bit more, it could create problems when the batteries get older.
Pete

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #34 on: November 19, 2016, 04:07:16 PM »
Hi Welshman I am not a battery expert but the idea you have of paralleling up each 12 volt section seems like it would work. The main thing that I could see as a problem with it, is if one battery or cell dies or goes short circuit then all the preceding batteries will drain into it. You could end up with 4 times the short circuit current or alternately all the battery strings drained flat at once.
That one may be worth looking into a bit more, it could create problems when the batteries get older.
Pete

Thanks for the input, there seems to be plenty to consider.

This unit is now modified to switch off and on for a split second when generator power is lossed to try to soften the chances of the mosfets being blown when it reverses the direction of flow when at zero crossing on the waveform.

What do you think of placing an ac motor run cap across / inline of the ac output of the inverter, could i theoretically achieve the ability to maintain power during that split second reset?

something like this perhaps? http://www.ebay.co.uk/itm/1pc-CBB65A-1-450V-100UF-Air-conditioning-startup-capacitor-125-50mm-new-DIY-250g-/291551824164?hash=item43e1d7c924:g:4mMAAOSw3ydV4l4n

edit - could a large cap be used to filter the ac from the toroids so it doesnt blow the fet's in the first place?

Offline sunnypower46

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Re: Just bought a powerjack 15000, modding.
« Reply #35 on: November 19, 2016, 06:41:23 PM »
Followup:  My adjust resistor is labeled "1500".

Regarding your battery bank:  I have three series strings of two each 12volt.  The 24 volt output of each string goes to PJ via separate cables.  So, they parallel up at the PJ input.  In each series string I have a 100-0-100 shunt style analog ammeter to show the charge and discharge into each string.  Now, you would expect the strings to share the current equally, but they typically do not.  This gives me something of an early warning as to battery health.  It also gives me a reason to swap batteries around within the bank.

You could do this easiest with the right side configuration and also embrace Pete's observation.

Offline rossw

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Re: Just bought a powerjack 15000, modding.
« Reply #36 on: November 19, 2016, 06:55:16 PM »
Welshman, I agree with Pete re using a metal strap.  Not a good idea.  Need to use something non-metallic.

Not sure I completely agree. I think metal will be fine, as long as it doesn't form a complete loop. If the attachment points at either end are insulated, the loop won't form a shorted turn.

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #37 on: November 20, 2016, 04:27:50 AM »
Hi Welshman I am not a battery expert but the idea you have of paralleling up each 12 volt section seems like it would work. The main thing that I could see as a problem with it, is if one battery or cell dies or goes short circuit then all the preceding batteries will drain into it. You could end up with 4 times the short circuit current or alternately all the battery strings drained flat at once.
That one may be worth looking into a bit more, it could create problems when the batteries get older.
Pete

Thanks for the input, there seems to be plenty to consider.

This unit is now modified to switch off and on for a split second when generator power is lossed to try to soften the chances of the mosfets being blown when it reverses the direction of flow when at zero crossing on the waveform.

What do you think of placing an ac motor run cap across / inline of the ac output of the inverter, could i theoretically achieve the ability to maintain power during that split second reset?

something like this perhaps? http://www.ebay.co.uk/itm/1pc-CBB65A-1-450V-100UF-Air-conditioning-startup-capacitor-125-50mm-new-DIY-250g-/291551824164?hash=item43e1d7c924:g:4mMAAOSw3ydV4l4n

edit - could a large cap be used to filter the ac from the toroids so it doesnt blow the fet's in the first place?

after a bit of thought, turns out i will get 10ms max by using an ac cap this way and drawback would be the cost of constantly charging it, but dont put a cap on the output of a modified wave only full wave.

to save battery power it could be diconnected out of the circuit after generator is off.

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #38 on: November 20, 2016, 04:31:17 AM »
Followup:  My adjust resistor is labeled "1500".

Regarding your battery bank:  I have three series strings of two each 12volt.  The 24 volt output of each string goes to PJ via separate cables.  So, they parallel up at the PJ input.  In each series string I have a 100-0-100 shunt style analog ammeter to show the charge and discharge into each string.  Now, you would expect the strings to share the current equally, but they typically do not.  This gives me something of an early warning as to battery health.  It also gives me a reason to swap batteries around within the bank.

You could do this easiest with the right side configuration and also embrace Pete's observation.

thanks for the resistor value.. 1500, that's 150 ohms.

150 ohn for 8000 PJ
100 ohm for 15000 PJ
50 ohm for 30000 PJ??

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #39 on: November 20, 2016, 04:35:39 AM »
Welshman, I agree with Pete re using a metal strap.  Not a good idea.  Need to use something non-metallic.

Not sure I completely agree. I think metal will be fine, as long as it doesn't form a complete loop. If the attachment points at either end are insulated, the loop won't form a shorted turn.

that's puts the simple method of a jubilee clip and some rubber out of the question. would have been able to get that tight to reduce vibration damage.

i've settled for some straps and silicone to reduce friction from vibration.

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #40 on: December 01, 2016, 01:29:51 PM »
Update on progress.


Offline oztules

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Re: Just bought a powerjack 15000, modding.
« Reply #41 on: December 01, 2016, 03:16:07 PM »
Looks like someone is having fun :)

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

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #42 on: December 02, 2016, 03:48:01 AM »
Looks like someone is having fun :)

........oztules

Thanks. It's been interesting and quite fun. I would like to take the opportunity to say that the information you have given in your forum posts has been invaluable in this project.

Offline Pete

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Re: Just bought a powerjack 15000, modding.
« Reply #43 on: December 02, 2016, 02:38:31 PM »
Hello Welshman, on the busbars, make sure that the batteries are protected from objects being able to be dropped on them. I have had a battery explode in my face many years ago, not what anyone wants.
I have used two methods of insulating bus bars, the traditional method is to use heatshrink and just cut enough away for good connections to be made.
A much cheaper option is to slide pieces of poly pipe over the bar as insulation. I have used poly pipe as hot water pipe insulation too, it works great and is much cheaper than lagged pipe or heatshrink.
Just a thought to keep in mind, you have a capacity to supply very large fault currents if a spanner is dropped.
Cheerio
Pete

Offline welshman

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Re: Just bought a powerjack 15000, modding.
« Reply #44 on: December 03, 2016, 01:21:34 PM »
Hello Welshman, on the busbars, make sure that the batteries are protected from objects being able to be dropped on them. I have had a battery explode in my face many years ago, not what anyone wants.
I have used two methods of insulating bus bars, the traditional method is to use heatshrink and just cut enough away for good connections to be made.
A much cheaper option is to slide pieces of poly pipe over the bar as insulation. I have used poly pipe as hot water pipe insulation too, it works great and is much cheaper than lagged pipe or heatshrink.
Just a thought to keep in mind, you have a capacity to supply very large fault currents if a spanner is dropped.
Cheerio
Pete

Thanks Pete, don't I know it! Had an incident yesterday where I was lining up the bars to final connect. One of the busbars went to fall and i reached to grab it to stop it falling on the rest of the bars, at that point i realised (due to current flow through arms)  i was holding 48v + in the left hand and - in the right hand, instantly the copper bar became magnetised and pulled itself out of my hand. The shock was interesting and despite me wearing rubber gloves. The bar proceded to short out and it burnt through one of the loose 8mm bolts I'm using as busbar inter-connects. I will definitely be insulating the entire exposed bar as a safety precaution!!

48 v @ 3200 amps is a hell of a lot of power. i've had my fair share of various voltage dc/ac shocks and the thing i notive about dc shocks is there is no warning like with 240v ac, you tend to feel the vibration a split second before the shock and know to let go. DC different thing entirely.