Reset SMA Sunny Boy TL-21/TLST-21 Inverter (SB 2500, 3000TLST-21, SB3000, 3600, 4000, or 5000TL-21

By performing a 'reset' (turning the Sunny Boy inverter off and on), the data transfer can easily be restored. Read here the steps you need to follow.

Resetting the SMA Sunny Boy TL-21/TLST-21 Inverter

Has the monitoring failed on your Sunny Boy 2500TLST-21, SB 3000TLST-21, SB3000TL-21, SB3600TL-21, SB4000TL-21, or SB5000TL-21 inverter?
03 juni 2016 11:56
Last updated on 08 april 2025 12:01
Reading time 1 min
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Has the monitoring failed on your Sunny Boy 2500TLST-21, SB 3000TLST-21, SB3000TL-21, SB3600TL-21, SB4000TL-21, or SB5000TL-21 inverter?

Sometimes it’s necessary to ‘reset’ the inverter when communication with the online monitoring has failed. Here’s how to do it:

  • Step 1

    Turn off the AC (alternating current) side. You can do this in the fuse box by switching the circuit breaker for the solar system (identified by the Zonnefabriek sticker) down.

    GROEP ZONNESTROOM

    Step 2

  • Step 2

    Next, go to the inverter. You will see that it is now in error state because the AC has been turned off. We will now also turn off the DC (direct current, coming from the panels). To do this, pull out the ESS (Electronic Solar Switch) from the device. The ESS is a component located at the bottom of the unit. It has icons indicating its function. In the image below, you can see the position of the ESS (circled in red). You can pull the entire component vertically down from the device using your fingers at the back of the ESS.

    SBTL21 met ESS omcirkeld

    Step 1 Step 3

  • Step 3

    The device is now turned off on both the AC and DC sides, but there is still residual voltage in the capacitors. You can tell by the screen that is still lit and the LED lights next to the screen. After about half a minute, the screen will turn off, and the device will be completely voltage-free.

    Step 2 Step 4

  • Step 4

    Now, we will restart the device, starting with the DC side by reinserting the ESS back into the device. Once it’s properly in place, a green light will begin to blink slowly next to the display.

    Step 3 Step 5

  • Step 5

    Finally, we go back to the electrical panel, where we turn the 'Solar Power' group back on by pushing the switch upwards.

    Step 4 Step 6

  • Step 6

    After some time, the communication with the portal server will usually resume. Note: The graphs for daily, monthly, and yearly yields may take a bit longer to return. Typically, they will only be visible again on Mijn Zonnefabriek and the Zonnefabriek app after a few hours.

    opbrengst grafiek op mijn zonnefabriek

    Step 5

Hessel van den Berg
Hessel van den Berg
Hessel is technical manager at Zonnefabriek. He regularly reports on current developments in the world of sustainable energy. Hessel has a talent for translating complex information into crystal-clear blogs.
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