Rapid Shutdown

[sidraja999]

Hello,

I am using the Tigo CCA unit and trigger the rapid shutdown feature by disconnecting the power to the CCA.

I want to setup an automated way of engaging the rapid shutdown feature when a ground fault happens.

I am planning to use a normally open switch that senses for current on the ground wire and then sends an output signal. I want to connect the output signal wire to the AUX port on the CCA.

Is there a current sensor switch that can detect DC current on the ground wire and then send an output signal? My amp level is about 12 amps but voltage can be up to 600 volts.

Thanks

 

[DIYrich]

My initial thought was: normally closed switch that controls power to the CCA (12-24v relay). When enough current passes to ground, it opens, power to the CCA is cut, TIGO RSD loosing signal, and shuts down. The problem is, that may clear the fault (no more power to ground), and re-energize the CCA, power resumes, and then you get into a cycle that will quickly kill your CCA, and RSD's.

You need some type of latching switch.

 

[sidraja999]

My initial thought was: normally closed switch that controls power to the CCA (12-24v relay). When enough current passes to ground, it opens, power to the CCA is cut, TIGO RSD loosing signal, and shuts down. The problem is, that may clear the fault (no more power to ground), and re-energize the CCA, power resumes, and then you get into a cycle that will quickly kill your CCA, and RSD's.

You need some type of latching switch.

Thanks. What if I use a DC current sensor that sends an output signal to a shunt breaker once it detects current on the ground wire? The shunt breaker would be connected to the power wire feeding the CCA unit and would trip once it receives a signal on the shunt wire. This would solve the "latching" issue that you mentioned.

Would this work?

 

[DIYrich]

Thanks. What if I use a DC current sensor that sends an output signal to a shunt breaker once it detects current on the ground wire? The shunt breaker would be connected to the power wire feeding the CCA unit and would trip once it receives a signal on the shunt wire. This would solve the "latching" issue that you mentioned.

Would this work?

What happens when the current is no longer detected (when the panels shut down)?

 

[sidraja999]

What happens when the current is no longer detected (when the panels shut down)?

The system will remain shutdown. The breaker will have to be manually flipped back on.

 

[DIYrich]

OK. Give it a try.

 

[sidraja999]

I cannot use the circuit breaker option. The manufacturer said that it will burn out the shunt trip coil.

This is the only product (Current sensor) I could find but it does not state the max voltage it can sense. The ground wire can carry up to 600 volts. Also, not sure how much output signal amps/voltage it will send to the Tigo CCA.

You might be right. The constant looping action might damage the CCA.