I have a problem with my U Power (Power Jack) 48v, 15000w split phase inverter. (120/230V output).

I heated up the sensor glued on the transformer until the alarm notice of overheating of transformer turned on and the inverter turned off.

but fan didn't turn on and there is no connection from fan to the fan plug on the control board.

its a four cable high speed fan can I override the sensors and have it stay on all the time?

ok the overload problem is solved with the new board but I would like to have my fan always on can you  show me how to connect it to a manual switch?

Sure can.  PJ used to have a switch for doing just that.

Have heard a number of customers noting that the new "v11.0" board overloads considerably sooner than the previous ones...

here is a foto of the inverter thank you

photo  of the inverter thank you

I see from  the picture it is a rev 11.1 control board  and is working .   The LF driver has no Led turn on  which is the new  design .   The red light alarm  is working to shut down the inverter .

The transformer look like my  8kw PJ invertetr  .  My 8kw PJ can do 2000 watts with the rev 11.1 control board .     Your 1800 watt heater and the solder iron will be more than 2000 watt and the red light alarm wiil shut down the inverter .   You can take the red and black wire from the fan and direct wire to the pos and neg terminal of thje battery cable  connection  and not use the sensor yellow wire .  Try a 1000 watt  hair dryer and it should work ok .   

my control board is 11.3 model the transformer is the new ASL4 transformer and this is the 15kw model

my system consists of 8 solar panels 380watts 38volts 9.2amps a piece wired in couples to give me 76volts for a 48volt system, connected to a midnight solar classic 150 charging 3 banks of batteries in mixed fashion lead agm 8 200ah northstar blue groups of 4 in series to give me 48v, another bank of 2, 48v lifePO 100ah each in parallel, and another bank with the same lifePO caracteristics. the litio banks are connected to 4 solar panels monocristaline,  400w, 40v 9.8amps in series and parallel to give me 80v feeding a Makeskyblue 60amp wifi controler, and the other bank with the same panels connected to a powermr 60amp controler, and all this connected to a 15kw, 48v split phase power jack inverter, it handles anything I throw at it including motors and electric soldering, household appliances etc, and run it day and night without any need of the public electricity I bought this other inverter because my old one is just great and want to connect it in parallel to get even more power out of the system.

before I had 16 100ah agm bank and decided to sell half the bank and add these lithium lifePO batteries and gave me 100% improvement lasting all night with minimun discharge due to lithium maintaining its charge longer than the lead agm, but the lead agm handle heavy loads and they work fine together up to now.

You can run them to 2 separate panels, but you cannot connect the outputs together.  They'll blow FETs if you do.

thanks then I'll make an alternate panel where I can alternate them to save life or run the old until it dies but for now it doesn't seem to have any problems.the alternate idea seems better. I also have many spare parts I bought to fix this new one.

or I'll make another panel to handle one of the breakers, in the house the house is divided in two phases so I can put the new one to handle the tough work and the old to handle light work but both connected to the same battery banks is this feaseble?

 I bought this other inverter because my old one is just great and want to connect it in parallel to get even more power out of the system.

I am not sure how to connect the 2 inverter in parallel .   Your 15kw that is working good  is different from the Upower 15kw with the rev 11.3 control board .    My  8kw with the rev 11.1 control board  and ASL4 transformer will only do 2000 watts .     I  had the old discontinue  rev 10.3 control board in the 8kw powerjack and it will do 4000 watts  but not  with the rev 11.1 board  as any inductive load will shut down  like your Upower  do with the  red light alarm  .   

Yes, as long as the outputs are separate.  You can parallel the Neutral lines (grounding, etc.) but L1 and L2 output must be separate between the inverters.  They don't sync together, that's the problem.