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Using the Cloud Connect Advanced Aux Port for Rapid Shutdown applications

  • Updated

Use Cases:

  1. Do not want the CCA to lose power (normal method for rapid shutdown) since you will lose module-level information and third-party MODBUS data while the system is in rapid shutdown mode.
  2. There is a battery onsite. While in backup mode (the grid is out), if the battery suffers a deep discharge and shuts off, all power to the load center will cease. If that panel powers the CCA, it cannot come out of rapid shutdown mode to charge the batteries.
    Powering the CCA from a separate AC source and using the PV-Safe feature will ensure PV for battery charging.
 CCA Outlined Hi Res.png

This article discusses the installation of a manually operated switch connected to the Cloud Connect Advanced (CCA) data logger Aux port.

The most popular option for rapid shutdown compliance is disconnecting power to the Data Logger using an approved rapid shutdown initiator per the US National Electric Code article 690.12(C). Other countries may have similar rapid shutdown requirements.

An alternate method, using the CCA Aux port to disconnect the TS4s from their respective modules, is called PV-Safe. It is similar to a Rapid Shutdown, except it does not power off the CCA.


Switch/Button Overview

The Cloud Connect Advanced offers a PV-Safe (or PV-Off for previous version dataloggers) mode for PV module level disconnection using a Normally Open switch. 

 

ATTENTION!

Using a normally closed switch or wiring a dual-purpose switch incorrectly are the number one causes of service calls related to this application.

The switch must be in a normally open position for normal operation.

 

Latching Push Button

When the red button on this normally open device is in the out position, the system runs in a normal operating condition. When pressed, the button latches in the activated position (stays pressed), and the TS4s will enter rapid shutdown. Release the button by turning clockwise, which will resume normal operating conditions.


mceclip0.png

 

Disclaimer: The button above is a standard off-the-shelf item not included with the CCA. Your choice of buttons should have these features:

  • Operation mode: Normally Open (NO) button
    In most cases, NO or NC operation can be configured within the switch housing.
  • Latching mechanism: The button must have a latching mechanism (twist to release, key lock, etc.) so that the button stays in the closed position until released.
  • No outside-source voltage shall be placed on the AUX port (voids Warranty). The CCA generates its own voltage source.

 

Types of Systems

TS4 models compatible with the PV-Safe feature:

  • Safety - TS4-S, TS4-R-S, TS4-A-S, TS4-X-S
  • Optimizer - TS4-O, TS4-R-O,  TS4-A-O, TS4-X-O
  • Long String - TS4-L

TS4 models that do not support this feature: 

  • Diode Only - TS4-D
  • Monitoring Only - TS4-M, TS4-R-M

Connecting a Push Button to the Cloud Connect Advanced

When viewing the wiring ports on the CCA, the AUX terminals are located on the left side. 

 

mceclip3.png

 

Connect a single pole switch or button to the CCA Aux terminal as shown below.

When the switch is Open (off), the push button should be in the out position. The TS4s allow full module voltage to pass through to the PV inverter.

Normal Operating Condition

CCA NO off.png array out of rapid shutdown.png

Once the push button is pressed, the switch is closed, and the CCA senses 3.3V across the aux terminals. This triggers PV-Safe mode, and the CCA stops sending its keep-alive signal to the Tigo Access Point installed on the roof. The TAP stops transmitting the keep-alive signal to the TS4s, and they enter into rapid shutdown. While in this state, each TS4 allows 0.6V to pass through.

PV-Safe Condition

CCA NO on.png array in rapid shutdown.png

The CCA will stay energized, allowing module level monitoring from the TS4s. Any third party MODBUS devices (weather instruments, external CTs, etc.) will also continue to send their data to the CCA. For more information about connecting MODBUS devices to the CCA, refer to this Help Center article:

Connecting Third Party MODBUS Devices to the Cloud Connect Advanced

 

How to Wire Multiple Data Loggers to a single Shut-off Button

For larger commercial applications, up to 5 Cloud Connect Advanced devices can be connected to a single push-button switch.

Each CCA in this group of five must be connected to the push button using individual wiring pairs.

Do not daisy-chain the CCAs in parallel.

  • Connect the Aux terminal wires as shown.
  • Ensure the maximum distance between the shut-off button and the first CCA is under 100 meters (328 feet.)
  • Additional CCAs must be less than 100 meters (328 feet) apart.

Diagram.png

 

Cautions and Disclaimers

Here are some very important things to remember about PV-Safe installation:

  1. Follow all electrical safety precautions.
  2. Always follow local codes and regulations regarding rapid shutdown compliance.

 

Legacy Products

Tigo Legacy products (MMU and Cloud Connect) offer a PV-Safe solution (the predecessor to PV-Off). They included a PV-Safe button on the Data Logger, but also offered a similar terminal interface for adding a manual latching push button safety switch.

To read more about PV-Safe, go to: What is PV-Safe, and How do I Re-Activate my System?

 

Note: The original generation of CCA did not include the protocol for PV-Safe and required a software update to support this feature. If you have installed a button that does not function as expected (PV modules are not disconnecting from strings), please email Tigo Customer Success: se@tigoenergy.com

 

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