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SPF 3500-5000ES 09Fault

SPF 3500-5000ES 09Fault

09fault meaning:

Bus soft start failed

Triggering condition:

1.  BUS Voltage is lower than 400V,or Bus voltage is lower than 8 times of battery voltage


2.  It can’t reach targe voltage in 30 seconds.

Testing method:

a. Just connect battery into the inverter. Don’t connect Utility input and PV input into the inverter.

b. If the inverter still shows “09 Error” , check MPPT board firstly, you can put MPPT board into normal
inverter and confirm if it is ok.

c. If MPPT board is ok, you can replace mainboard directly

Malfunction point:

a. If you have confirmed that 09fault is caused by MPPT board, most of time, Mosfet or diode or driving circuit on MPPT board is damaged.

a. If you have confirmed that 09fault is caused by main board, most of time, Mosfet or diode or driving circuit or bus soft start circuit on mainboard is damaged.

DC-DC Circuit: It is used to convert battery voltage into 400V Bus Voltage

You can test 16 mosfets on DC-DC circuit via multimeter( most of time, 09fault is caused by these mosfets. If good luck, you can replace mosfet and repair it well.)

How to test MOSFET

  1. Firstly , Turn to diode position on multimeter

2. Every mosfet has 3 pins ( G, D, S ). Put black tong of multimeter on D pin and Put Red tong of multimeter on S pin

0.38-0.7V on multimeter is normal. If multimeter display zero, it means the mosfet has short

BUS Soft start Circuit: It is used to form 400V Bus Voltage before main circuit starts working. so that in case power surge of main circuit damage the mainboard

BUS soft start circuit like SPS, there is mosfet there that is easy to be damaged.


Replace MPPT board or Mainboard

Most of time, it is caused by damaged mosfets, you can try to replace them. If one of them is broken, please replace all in case potential issue

MOSFET model( DC-DC circuit on mainboard): CSD19505KCS/201A/80V/N/175℃/TO-220 010.0017800 ( you can request them from [email protected] based on the material code )

Photo-coupler model: FOD3120SD/8PIN/100℃/SMT 8-Pin(Lead Bend) OR TLP350(LF1,TP1)/8Pin/100°C/ SMD OR TLP352(TP1,F)/ 8PIN/125℃/SMT

MPPT Mosfet( SPS Circuit ): IXTP3N100P/3A/1000V/150℃/N/TO-220

MPPT IGBT( Boost Circuit): IGBT FGH60N60SMD/60A/600V/175℃/TO-247

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