External surge protection device (SPD)

To protect the PV system from overvoltages, a surge protection device (SPD) should be installed on the DC side between the inverter and the PV generator and another should be installed on the AC side between the inverter and the grid.

If you have installed the optional internal DC overvoltage protection module in the inverter, no additional external protection is required on the DC side.

The inverter can evaluate available external surge protection devices and can issue a message if an event occurs. For this to work, connect the message output of the external overvoltage protection module(s) without potential (potential-free) to the monitor input at the inverter's X402 terminal.

After commissioning the inverter, the external evaluation of the surge protection device must be configured in the Webserver as normally open (NO) or normally closed (NC).

External surge protection device as normally closed

1

Connection of terminal X402 for Smart Communication Board (SCB)

2

Surge protection devices (SPD) for AC and DC side

3

Control line from SPD to inverter

External surge protection device as normally open

1

Connection of terminal X402 for Smart Communication Board (SCB)

2

Surge protection devices (SPD) for AC and DC side

3

Control line from SPD to inverter

Carry out the following steps to connect the signal cable

DANGER

danger

Risk of death due to electrical shock and discharge!

  • De-energise device and secure against being switched on again.

INFO

Info

The signal cable is subject to the following requirements:

Conductor cross-section from 0.2 to 1.5 mm2

Max. length 30 m

Length of stripped insulation 8 mm

Observe the specifications for cable cross-sections in the manufacturer's instructions.

  1. Switch the DC switch on the inverter to OFF.
  2. De-energise the house grid and secure it against being switched back on.
  3. Install the SPD for AC and DC in the control cabinet or power distributor.
  4. Correctly route the signal cable from the inverter to the control cabinet and connect to the SPD following the wiring diagram provided by the manufacturer.
    With two SPDs, pay attention to how the signal cables are connected to each other: in series (for NC) or in parallel (for NO).
  5. Connect the communication cable in the inverter to terminal X402 for the surge protection device.
  6. Once initial commissioning has been completed for the inverter, the overvoltage protection must be activated and configured in the Webserver (evaluation of overvoltage protection).
  1. The message contact for the external SPD is connected.

Activating evaluation of the external message signal from the SPD

INFO

Info

The IP address can be read on the inverter's display.

  1. Call up the Webserver. To do this, enter the IP address of the inverter in the address bar of the Internet browser and confirm with ENTER.
  2. The Webserver page is opened.
  3. Log in to the Webserver as an installer.
  4. Select the menu item Service menu > General > Overvoltage protection .
  5. The Overvoltage protection page opens.
  6. Activate Evaluation of the external message signal (terminal X402).
  7. Under Signal is wired as, select the function normally open (NO) or normally closed (NC).
  8. Click on the Save button.
  1. The function is active.