RSD Between Tigo and Sol-Ark 15k

Hello,

I've been searching for the "best" way to enable RSD with the Tigo Optimizers and EPO with the Sol-Ark 15k. From what I've seen, the best method seems to be using pins 15 & 16 on the Sol Ark to drive a relay at the Tigo CCA. After that, there have been two methods.

1. Relay NC connection connected to the Aux Port on the CCA - When the inverter EPO is hit, power shuts off to the 15 & 16 pins, causing the relay to go from open to closed, and effectively "pressing the RSD button" on the Tigo CCA.
2. Relay NO connection interrupting the 24v power to the CCA. When the power shuts off, the tap stops sending a signal and the modules go into RSD.

I've read that when the EPO button is pressed on the Sol-Ark, the electricity from the grid can pass through to the load. That would allow the CCA to stay operational if that button is pressed. Seems like the relay option is the safest bet but which option is best?

Thanks!

I just have my CCA powered off a breaker in the "Load" panel, going to a step down converter to the CCA.

Therefore if the inverter shuts down, so does the CCA, therefore triggering the PV to turn off.

Simple.

With the 15k, if you press the Emergency Stop button, you lose all power to the load panel?

TechRider said:

With the 15k, if you press the Emergency Stop button, you lose all power to the load panel?

Click to expand...

I do not have an emergency stop button. I only have the on/off button on the front of the inverter, and the PV disconnect switch on the left side.

Approved in California in 2022.

TechRider said:

1. Relay NC connection connected to the Aux Port on the CCA - When the inverter EPO is hit, power shuts off to the 15 & 16 pins, causing the relay to go from open to closed, and effectively "pressing the RSD button" on the Tigo CCA.

Click to expand...

That's how I have mine wired with this relay. Just out of principle I'd rather use the shutdown signaling circuit rather than just killing power to the CCA.

My installer arrived with a N/C RSD switch. So, I supplied a SSR and did this. Yes, I know it doesn't do emergency shut down of the inverter, but it passed inspection.

My RSD switch is wired to the pins on the Sol-Ark 15K. The Tigo is powered from a breaker in my main panel. When the RSD switch is activated, it shuts down the Sol-Ark and thus my main panel. I tested it before my inspection. I also have a 200A disconnect after my meter, so if I have bypassed my Sol-Ark for some reason and you throw the disconnect, it also kills power to the main panel, thus the Tigo, thus killing the panels.

Hello. I ended up wiring a relay powered from the Sol-Ark 15/16 pins to the Tigo AUX port. I figured this will give me the best config as my IT equipment is on a UPS so if the Tigo is able to send a note, I should get an alert if someone ever pushes the EPO/RSD button.

The Aux port is connected across the NC connection. When the EPO button is pressed, the Sol-Ark shutsdown pins 15/16 causing the relay to close, connecting the AUX port. I haven't timed it yet.

Seems like Olphile's approach may be well suited to a totally off grid senario (no utility connection) where the inverter does not need to be shut down during an RSD event. Is this right?

That could be. If I did it over again, I'd get a DPDT switch instead of my SPDT switch. Then I'd wire both the inverter and the Tigo to the same switch. Or you could do it with 2 switches and shut them down independently. When I was thinking through mine, the only time that switch should ever need to be hit is if things went very very bad so it's best to get as much shut down as possible.