[NOT solved] Tigo/Sol-ark integration issue causing late start for solar production in cold weather ...

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    Greg Smith Community Moderator
    Early Adopter

    Hi Dan, the TS4-A-2F is rated to -40F, so I doubt temperature is affecting the MLPE. Where is the RSS Transmitter installed? That is rated to -14F.

    The Sol-Ark PV start voltage is 125VDC. This is the time of year when the weather is bad and PV production is at its lowest. Is there something on the array, like shading, snow, etc. that is preventing the Voc from hitting 125V until later in the morning?

    You could try disconnecting the TS4s to see if you get the same behavior. That would narrow it down.

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    Permanently deleted user

    after a couple more hours research, I think I have figured out the mystery.....

    The Sol-ark-8kOutdoor has internal 12v output inside the cabinet rated to output 100mA (1.2watts), and just enough room to put the Tigo Core and RSS transmitter inside the Sol-ark. In the Sol-ark manual they show a schematic powering the RSS directly from the internal 12v, so thats the way I did it. It works *most* of the time.

    What I am thinking is that under *certain* conditions, either the Sol-ark 12 is dropping below Tigo requirement, or Tigo peak power requirement is too much and the circuit cuts out and shuts down RSS, which signals shutdown to PV.... and doesn't re-power and re-set until the sol-ark internal 12v power gets back within range.

    So..... until Sol-ark can improve their internal 12v power supply, and warranty it can run the Tigo RSS,  I'd say that installers should stick with using the external Tigo enclosure with DIN rail mounted power supply.

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    Greg Smith Community Moderator
    Early Adopter

    Very observant, Dan. I should have asked how the transmitter was connected. In June of this year, Sol-Ark revised their manual to reflect a change in the way the rapid shutdown device is powered.

    Their internal 12V pin is rated at 100mA, but our RSS Transmitter requires 1A. Consequently, you will need to use an external 12V/1A DC power supply. Tigo offers one and our distributors carry them. This external power supply will solve your issue. 

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    Permanently deleted user

    The Sol-ark manuals were not revised very well..... there is red text clarifying that their pins supply 100mA, but they left in the schematic showing their pins used to power a transmitter. I think a LOT of installers, especially DIYers, will miss the text and just go by the schematic on this. It's not Tigo's fault, but somebody should reach out to Sol-ark and make sure they show the 'standard install' including your 1A power supply and TX in the external Tigo enclosure 'kit' unless they upgrade their pins to 1A.

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    Greg Smith Community Moderator
    Early Adopter

    Thanks, Dan. I reviewed the 12kW and 15kW manuals, and it looks like the 8kW manual is the only one that overtly states the power requirement. I'll reach out to them.

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    Permanently deleted user

    what threw me, as a person unfamiliar with Tigo's, was the apparently conflicting text saying that TIGO optimizers are compatible, but don't use the 12v to power TX, and that the schematic shows using the sol-ark pins to power the TX. The Tigo 1A power supply worked out fine, but it took me hours to figure out that the Tigo TX power requirements are 5.5peak/0.85continuous watts.... so the 1.2 watts from Sol-ark actually worked *most of the time*. I probably would not have noticed the late production starts in a grid-tied system, but this install is off-grid, and every hour of production is important.

    I don't know WHY the Tigo seems to require more power when it's cold outside. The system installed late summer was working fine until temps dropped below freezing recently, and that's what made it hard to track down.

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    Greg Smith Community Moderator
    Early Adopter

    The temperature component is interesting, considering the RSS transmitter is rated at -40F. I forwarded this conversation to one of our engineers to investigate. I will keep this post updated. Thanks again, Dan!

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    Permanently deleted user

    The interesting part is that the TX is inside the sol-ark inside a nice warm garage... only the TS4-A-2F units are outside on the roof subject to cold. After careful review of data available in Sol-ark 'powerview' app I was able to see that on cold mornings when the Tigo TX shut down, the PV array voltage bumped up from overnight 1.5-1.9vDC to 4-5vDC right around sunrise....and stopped there until 11am when things on the roof dropped. On warmer mornings, the array voltage rose with the sun to operating voltage and production started with sunrise.

    For whatever reason, power draw at the transmitter is higher when the TS4-a-2f units on the roof are cold, and the sol-ark 12v pin output (1.2 watts) could not keep up, TX shut down, and did not restart until much later in the day.

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    Permanently deleted user

    I *could* try disconnecting the TS4-A-2F units..... but with the 2F being one unit per 2 modules, I'd have to spend a couple hours getting to this install, 'un-manage' my wiring to put the panels in a string without Tigo, and basically break code by not having RSD on the modules and DC run into the house. It would be easier to swap out the suspect units for new ones that Tigo has verified to work properly after freezing, and let Tigo test mine to their hearts delight.

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    Greg Smith Community Moderator
    Early Adopter

    We have noticed inconsistent operation when the RSS Transmitter uses the Sol-Ark internal 12V power supply regardless of the weather conditions. This same behavior has been noted for systems in AZ in the summer. This is why we asked Sol-Ark to remove their statement of Tigo RSS Transmitter compatibility.

    The Sol-Ark internal pin is only rated to 100mA, and the Transmitter needs 12V/1A. It may work some of the time, as you have shown, but for an off-grid install, which needs to be bulletproof, you must use an external 12 volt power supply for the RSS Transmitter.

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