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Just need some advi...
 
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Just need some advice

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(@scoobybob)
New Member
Joined: 2 years ago
Posts: 1
Topic starter  

Hello all,

I'm setting up an off-grid camper that will house my amateur electronics lab that im currently running off a solar array with plenty of juice but only two 1500w single phase inverters. I have a power jack lfpsw split phase inverter with dual 48v input from 2017 that my father gave me. He works for Kohler and a customer had given it to him. It had gotten rained on with the top off and from a quick inspection from what I can tell only the MOS board and transformer are in a usable condition. My question is could I convert it to 24v input or just out right replace it for cheaper than replacing all the damaged boards? 


   
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(@notmario)
Reputable Member
Joined: 3 years ago
Posts: 314
 

You'd have to look at the transformer. If there is two sets of primary windings in series, then you can put them in parallel to double the ratio. Then change the jumpers on the control board, and change the fans to 24v fans. That should do it.

If you don't have two primaries in series, you should still be able to do it by substituting the center-tap wire with L2. (swap L2 wire and central tap wire) That will produce a 120v inverter between L1 and N. The other steps in the previous suggestion still apply. Humorously, you can then use L1-L2 or N-L2 to access a  a split-phase 60v.

Campers don't usually have a split-phase configuration, so the latter option might be preferable.


   
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(@dickson)
Noble Member
Joined: 4 years ago
Posts: 1058
 

 I have a power jack lfpsw split phase inverter with dual 48v input from 2017

Sorry that  Powerjack in China  only make the rev 11.3  control board .   The rev 11.3  control board will blow up the Fets  on all  older PJ  inverter .    Only a rev 11.3 complete main board from China  will have  matching  ribbon cable  to the  rev 11.3  control board .   You can  make a  ribbon cable that work with older PJ  inverter by  tracing  the 10  FETs  wire   to  the rev 11.3 control board but not easy to do  .    I  do not think Sean  will warranty  any control board  if he has one  and  not easy  to  convert  48v to 24v .      


   
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(@sid-genetry-solar)
Member Admin
Joined: 4 years ago
Posts: 2890
 
7 hours ago, NotMario said:

If there is two sets of primary windings in series, then you can put them in parallel to double the ratio.

Worth noting that on the large PJ inverters with the dual long mainboards (which I'm guessing this MAY be!), even if there's 2 sets (or 3 sets--or 4 sets!) of transformer wires going to the FET boards, PJ never ensures that the groups of wires are electrically separate from each other.

If they did, dropping a 48v inverter to 24v would be quite easy. 

But every single time I've checked, you'll find a dead short between all sets of wires.  My guess is that when winding, they put all the necessary windings on...then start grabbing a random 10 strands per crimp.

It would technically be possible to cut one set of crimps off, use a meter to determine which wires were what...abrade the enamel off the cut ends, and then crimp new terminals on them while keeping the transformer in at least 2 electrically separate sets.  Depends how many tools are available 😉.


   
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(@notmario)
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Joined: 3 years ago
Posts: 314
 
Posted by: @sid-genetry-solar
But every single time I've checked, you'll find a dead short between all sets of wires. My guess is that when winding, they put all the necessary windings on...then start grabbing a random 10 strands per crimp.

Hey, if i were working for peanuts, that's what i'd do too. "Why's it matter," right?


   
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