Tigo Cloud Connect Advanced (CCA) and Cloud Connect data loggers can have a Normally Open switch connected to the AUX port, which when Closed initiates MLPE disconnect of panels from strings.
This feature is currently named PV-OFF. It was previously named PV-Safe on the control panels of Maximizer Management Unit (MMU) and Cloud Connect (CC) models of data loggers.
When the switch is Closed, the CC/CCA will command Optimizers to disconnect the PV modules from their strings. Any TS4 model capable of PV Module (solar panel) disconnect will 'shut down', i.e. disconnect the panel from the string wiring, and thus to the Inverter. This results in 0 Volts DC to the Inverter. Without the switch, the data logger must be powered off to initiate disconnect, which is named Rapid Shutdown.
The TS4 models capable of module-level disconnect are: TS4-S, TS4-R-S, TS4-A-S, TS4-O, TS4-R-O, TS4-A-O, and TS4-L (all but M monitoring only model units, or Fire Safety model units which use PLC signaling over the string wiring)
Re-connecting panels to the strings:
- Return the switch to its OFF position which is the Open Circuit position.
- When using a Cloud Connect or MMU, also navigate to menu item "2.2 Modules ON".
Cloud Connect Advanced, Front Panel, AUX terminals
See below for wiring a switch to multiple Cloud Connects in a single system.
On the left-hand side is the AUX port to which the Normally Open switch is connected.
The DIN rail-mounted direct-wired power supply is shown below, just beneath the CCA. It appears as the white unit. Note that the CCA has no AUX switch connected yet.
Note: Cloud Connect / CCA must have a software version higher than 2.8.5 to support this feature. Email firstname.lastname@example.org with system ID or street address if the button does not work (PV modules are not disconnecting from strings) after being wired to data logger, and the switch is in the closed position (activated).
The button shown above is an off-the-shelf button, not provided by Tigo, that has these features:
- Operation mode: Normally Open (NO) button
- Note, NO or NC operation can usually be configured by jumpers internal to the switch housing.
- Latching mechanism: the selected button must have a latching mechanism (twist to release, lock with key, etc.)
- Power production will resume upon releasing the button by unlatching it, returning the switch to its Open position, and thus no longer connecting the AUX terminals together.
CCA Wiring diagram and instructions.
- Up to 5 data loggers can be connected to a single switch.
- Be sure to wire the grounds together, and the signal switch wires together, as shown in the diagram above.
- No outside-source voltage MAY EVER be placed on the AUX port
- The ground of the system should be connected to the 24 VDC "-" Negative terminal
- The left-hand pin should read close to 3.3 VDC when the switch is OPEN. 0 VDC when the switch is CLOSED (activated)
- When connecting multiple CCAs to the same switch be sure that the maximum distance between the shut-off button and the first CCA is under 100 meters.
- Additional CCA's also must be less than 100 meters apart from each other
UL certified buttons:
- Idec FB1W-HW1B-V411R - Switch and enclosure, 40mm head, Pushlock with Turn Reset, Plastic, 1NC-1NO
- Goele - LA115-A5 Push button
- 1688 - A22-RP-SW/K10, K01, K11
Cautions and Disclaimers:
1. During the installation of any mushroom buttons, please follow the same safety precautions as if dealing with a system that is powered on.
2. DANGER: Prior to servicing a system, please use a voltmeter to make sure that neither voltage nor current are present and flowing through the PV array after having pushed the external shutdown button.
3. External mushroom buttons are a convenient way to disconnect a system, but are not NEC 690.12 2014 or 2017 compliant; please always follow NEC required procedures to provide the appropriate means of disconnection and signage to emergency personnel.
How to Wire Multiple Data Loggers to a single Shut-off Button
For a shutoff button to work on a system with multiple MMU type data loggers, each logger must be connected to the shutoff button on its own individual wires that run directly from the switch and are not daisy-chained in parallel.
Figure 1: connection of multiple CCAs to a single switch
Multiple CC and MMU Switch Wiring