Replacing or Removing a CCA from a Discovered system, requires a period of zero production.
Reason: When a Tigo system is installed and the Discovery process is completed, the automatic Rapid Shut Down (RSD) feature of the Tigo MLPEs is enabled. The catalyst for the automatic RSD reaction, is the loss of radio communication with the TAP (Tigo Access Point) and Data Logger (CCA). Once Discovered, a system will require continuous radio communication from the TAP and Data Logger, in order to be active. If this radio communication is lost, the system will go into RSD and the inverters will turn off.
Distinction between "Discovered" and "Un-Discovered"
Discovery is the final step of the commissioning process in which the system's Data Logger searches for and connects to all of the MLPEs associated with its system. All Tigo MLPE's are sold in the "open" position, meaning that they do not offer RSD functionality until Discovery has completed.
TS4 units that complete this process are "Discovered," and their RSD capabilities are enabled. These units now require two things to continue to produce power:
- Communication from a Data Logger via a TAP (or Gateway)
- Current draw from their system's inverter
Without these two scenarios, the Discovered system's MLPEs will shutdown.
On the other hand, TS4 units that have not been Discovered or have been deployed without communication equipment (aka Blind Deployment) are not enabled for shutdown mode. They will produce power, but they do not provide safety shutdown features to your system.
Why the Distinction?
It is important to be aware of this in some specific circumstances:
1. If your Data Logger is powered off (due to a power outage, etc), the PV Modules will not produce power until the Data Logger has received AC power, again.
2. If you or a system owner wants to replace a Data Logger on a discovered system for any reason, the system will be offline until the replacement is made. After replacement is installed and has Internet service, send an email to firstname.lastname@example.org with the system ID and CCA serial number. A support team member will assist by sending a Discovery command, remotely.