Power Jack Choke

[Buzz]

Bought a 12V 8000W UPower with the intention of running a 2kw well pump, on the side it says to use a choke. The well pump is 240v would I need two chokes? The listing didn't mention the need for a choke and the seller is no longer on ebay

 

Choke: https://www.ebay.com/itm/394138327667?hash=item5bc4799a73:g:m28AAOSwXVNiu8em

Edited July 6, 2022 by Buzz

[Sid Genetry Solar]

Don't think you'd need 2; at best, the external choke is a Band-Aid solution to the real problem: poor MOSFET drive.

[Buzz]

1 hour ago, Sid Genetry Solar said:

Don't think you'd need 2; at best, the external choke is a Band-Aid solution to the real problem: poor MOSFET drive.

Thank you, 

Bought it before I realized there was better but heavier and much more expensive inverters. 

[Sid Genetry Solar]

I mean, all knocking aside, PJ inverters can function pretty decent for small/light loads.  But they won't do what the label says 😉.

[dickson]

Choke: https://www.ebay.com/itm/394138327667?hash=item5bc4799a73:g:m28AAOSwXVNiu8em

That is David  ebay account  and has good review and this account is still active .    He has 2  other  ebay  accounts  also active  and has good  review  .    His ebay  auction account  is shut down by ebay  for  a well  planned  scam  by PJ  in China .       

I mean, all knocking aside, PJ inverters can function pretty decent for small/light loads.  But they won't do what the label says.        I  brought 2  PJ inverter2  from David  that is still working  every day  at less that  4000  watts .   

[RobertM]

On 7/6/2022 at 5:19 AM, Buzz said:

Bought a 12V 8000W UPower with the intention of running a 2kw well pump, on the side it says to use a choke. The well pump is 240v would I need two chokes? The listing didn't mention the need for a choke and the seller is no longer on ebay

 

Choke: https://www.ebay.com/itm/394138327667?hash=item5bc4799a73:g:m28AAOSwXVNiu8em

Keep us posted. I have the 24V Power Jack version of this inverter, and want to power a 1/2hp 240V 3-Wire pump. My initial attempts were failures. The inverter shut down within a few seconds.

[Steve]

That sounds really close to what I was doing when my upower 10k blew.

If the choke makes it work I would love to know

Mine worked at first then shorted output FETs 

 

 

[dickson]

want to power a 1/2hp 240V 3-Wire pump. My initial attempts were failures. The inverter shut down within a few seconds.

The pump is  1200 watts  and should start .      Try to start a  microwave oven  which is 3000 watts .        Try 4/0 cable  copper wires  .         The battery connection inside may be loose .       Try  turn on a hair dryer first  and  then  turn on the pump  second .   

[Steve]

Tho open pic has a display on it

The others don't

What size is it.

Mine is the upower 10000W

And could start a 2kw pump.

Didn't live long doing it but was successful 

 

 

[dickson]

And could start a 2kw pump.

Didn't live long doing it but was successful 

The buyer on ebay  never know  what  PJ  put in the case  .     What I got is not what ebay  show  in auction  .    PJ  made a 40 FETs  prototype  8kw  inverter and that will  start  a 5 hp  air compressor  to my surprise  and is still  working .      

[RobertM]

If an AC choke would be beneficial, I wonder if someone could identify something available for less than rayjunglepower is charging. He wants $100 to $200 for his three models. If I used one for starting maximum 230V 3000 Watt motor, what would be the parameters? 65uH  220A? Sid wrote that he felt that even with 230V power (two hots) one choke would be sufficient.

Would "Vertical Toroid Magnetic Inductor Wire Wind Wound 50uH 20A Coil" work if the pump is 15A?

Edited July 18, 2022 by RobertM

[dickson]

It has 2 big caps and the ASL-2 transformer .          PJ  put a mini tiny mainboard  with 2 capacitor  is not enough and  ASL2.0  transformer  is a scram  to be a 8 kw inverter .      My  8 kw PJ  has a ASL5.0 transformer  and 4 capacitors .    I  test with 2 capacitors on the mainboard  of my 15 kw PJ and it will not start a microwave  with the  rev 11.1 control board .       rayjunglepower    account is closed on ebay  but  you can buy the  150 dollars  choke from his  other ebay account  and is easy to install  on  L1 and N    and maybe one will  be enough  .      IF PJ  install  4 capacitors     and mosboard with 6 FETS   and  ASL3.0  transformer   but instead   you need  a big choke  which   maybe still not work .    

[RobertM]

My pump motor is 15A. Would a 50uH 20A choke work? 

[dickson]

My pump motor is 15A. Would a 50uH 20A choke work?        

The surge  of a 1/2 hp motor mabe 15A  but running is 5A .     15A  at 240vac is  3600  watts  wich is more than a microwave oven .    From the DC side  3600 watts at 24VDC   is   150A  and is more  than  20A  .       IF  your inverter can not start a microwave  now   then  no choke will help .       The  rev 11.3 control board will give a red light  alarm and shut down and  not blow the FETs .    IF  no red light alarm  but inverter shut down  then measure  the battery cable voltage  .     A properly  design inverter  do not need  choke  on L1  and N  .    

[RobertM]

Just now, dickson said:

My pump motor is 15A. Would a 50uH 20A choke work?        

The surge  of a 1/2 hp motor mabe 15A  but running is 5A .     15A  at 240vac is  3600  watts  wich is more than a microwave oven .    From the DC side  3600 watts at 24VDC   is   150A  and is more  than  20A  .       IF  your inverter can not start a microwave  now   then  no choke will help .       The  rev 11.3 control board will give a red light  alarm and shut down and  not blow the FETs .    IF  no red light alarm  but inverter shut down  then measure  the battery cable voltage  .     A properly  design inverter  do not need  choke  on L1  and N  .    

The choke that Power Jack is suggesting is an AC choke. It goes on the output side, right? If I buy a 50uH 20A choke, will that suffice? I will try to measure the amps required to start the motor. The motor is 230V and the surge amps are about 10A, so the watts are ~2500W. This maybe be possible with my inverter.

[dickson]

 The motor is 230V and the surge amps are about 10A, so the watts are ~2500W. This maybe be possible with my inverter.

I  know that the pump surge is 10 amps  but a 50uH 20A choke  will not  start a well pump  because the surge may last  10 seconds  and a 20A  choke will not help  when the   battery side  is drawing  100 to 150 amps .     IF the surge last less than  1 second like a heat pump  then it may work .    The problem  is that the dc voltage will drop fast and then  your AC side may drop to 180VAC and the well pump will not start  because the surge last  10 seconds  and your AC voltage will be too low .     The choke is to keep the AC voltage near  230vac  but because the ASL2.0 transformer  is  too small  to keep the voltage near  230vac for 10 seconds .      I  do not know of any well pump that  start in 1  second  unless there is no water  .       

[RobertM]

5 minutes ago, dickson said:

The problem  is that the dc voltage will drop fast and then  your AC side may drop to 180VAC and the well pump will not start  because the surge last  10 seconds  and your AC voltage will be too low .     The choke is to keep the AC voltage near  230vac  but because the ASL2.0 transformer  is  too small  to keep the voltage near  230vac for 10 seconds .       

I thought the choke was to protect the mosfets from feedback from the pump motor?  To address the voltage drop, which I think is the true problem, I have a 24V capacitor bank that I can connect to the dc side. I haven't fully tested that idea because I couldn't make good high-amp connections to the circuit board. I have nickel strips now and 4 gauge copper wire now, so I will try again.

[dickson]

I thought the choke was to protect the mosfets from feedback from the pump motor?

The  choke  protect the FETs from overload  like a pump that do not start  and also when the pump shut off .     The rev 11.3 control board do not allow testing  as it shut off the inverter in less than a  second .    The choke  do  not have a chance  to help the pump  as  all power is shut down  and you do not have 10 seconds to see if the FETs  blowup or if the pump works .      This is good  but it  indicate the transformer is  not  design  properly   and  probably nothing  to fix  .     

Edited July 18, 2022 by dickson
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[Steve]

In my experience with fets they tend to instant fail from over current unlike bipolar transistors which just get hot.

That's not to say the fets aren't better, just that the safe parameters for them are much closer to catastrophe failure points than their predecessors.

Because the slicer bridge is still a HF inverter feeding a LF transformer the choke on the primary is critical for limiting the pulse current

Because it's a bridge slicer a FET sticking on one phase will destroy the FETs on the alternate phase of the same transformer terminal as soon as energized 

 

 

 

[Steve]

In my experience with fets they tend to instant fail from over current unlike bipolar transistors which just get hot.

That's not to say the fets aren't better, just that the safe parameters for them are much closer to catastrophe failure points than their predecessors.

Because the slicer bridge is still a HF inverter feeding a LF transformer the choke on the primary is critical for limiting the pulse current

Because it's a bridge slicer a FET sticking on one phase will destroy the FETs on the alternate phase of the same transformer terminal as soon as energized 

 

 

As far as FET drive mine has 10v drive signal with 1uS rise and 0.5uS fall times.

That seems like decent drive to me

 

[Buzz]

Choke arrived, way bigger than I thought it would be. Need two more batteries before I can test it

[RobertM]

Let us know if you notice any benefits when using this choke. I am testing small aftermarket chokes on my "8000" Power Jack AMG inverter. I connected both of my small battery banks to the inverter, and started a 1/2 hp motor. I needed a small auxillary load running before the motor would run continuously.