MPPT RS 450/100 dead

Q&A and troubleshooting
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1

Hi I did an install for my parents with the following components.

  • Multiplus 2 5000VA

  • MPPT RS 450/100

  • 2 strings of 10 x Jinko Solar Jinko 445 Wp JKM445N-54HL4R-V-

    B-2

  • Seplos 16kwh battery

Everything worked for a few months. But all of the sudden the mppt stoped working.

It started with the solar current dropping to 0 while the voltage was still OK.

After a day the mppt did not show on the vrm that’s when I noticed the problem.

A 2 days later the mppt was back online and I saw an error in the remote console “Short circuit”.

One string showed 0V while the other 380V but no current.

I looked this error up and some had this issue because of a firmware problem so I downgraded the firmware.

After the firmware transfer both strings showed 380V but no current.

The day after the mppt was back offline. And I had time to go over there. The fuse for the mppt was burned. But when I replaced it the mppt did not turn back on.

I want to know for sure I did not make a mistake before replacing trough warranty or buying a new one in case its my fault. :grimacing:

IMG_9681
IMG_96811920×3413 239 KB

Scherm­afbeelding 2025-10-04 om 17.34.47
Scherm­afbeelding 2025-10-04 om 17.34.474242×1152 278 KB

2

Hi check that it not on of these units, they where recalled and replaced FOC.

3

No this one is HQ2508 so build after those units.

4

The fact that the mppt blew a fuse mans nothing good happened there. As an fyi never replace a fuse until you know why it blew.

There is a pre rms check form so you can cover all ypur bases before sending it on.

Also going to assume your photo ofls from before pv connect as the mc4s are empty. Ao a nice reference photo.