Performing The Vac Test - SMA NR-STP90-5-AST Instrucciones Para La Sustitución

9 Performing the VAC Test

LED status
Green LED is flashing The DC input voltage is still too low or the inverter is monitoring the
The red LED is glow-
ing
10. Ensure that the inverter feeds in correctly.
11. To check the correct functioning of the SELV circuit, perform a fan test:
• Call up the user interface of the communication product or software and log in as Installer
or User.
• Select the parameters Device > Cooling system > Fan test. If the fan starts, the SELV
circuit is fault-free. If the fan does not start, contact Service.
12. Perform update to the latest firmware version of the inverter (see inverter operating manual).
13. Re-enter the set parameters, especially the GridGuard parameters (see inverter operating
manual).
14. If the inverter is registered in Sunny Portal, replace the inverter in Sunny Portal (see installation
manual "Replacement of SMA Devices in Systems with Communication Products" at
www.SMA-Solar.com).
15. Perform the VAC test (see Section 9, page 18).
9 Performing the VAC Test
Due to the replacement of the assembly, elements in the supply voltage measurement area were
replaced. To ensure that the supply voltage measurement in the inverter has the required accuracy,
the installer must carry out a VAC test.
The VAC test compares the AC voltage present in the utility grid with the AC voltage measured by
the inverter. The inverter may display up to 5 V more or 1 V less than the applied AC voltage.
Requirements:
☐ A measuring device suitable for the VAC measurement must be available.
☐ During measurement, devices causing fluctuations in the utility grid (e.g. other inverters) must
be switched off or set to Stop.
Procedure:
1. Log into a communication product (e.g. Sunny Explorer) using the "Installer" user group and
establish a connection to the inverter (refer to the communication product manual).
2. Set the parameter Operating mode from MPP to Stop.
3. Make sure that the VAC voltage measured by the inverter is displayed. This can be done on
the display of the inverter or via the communication product.
4. Measure the AC voltage as close as possible to the inverter.
5. Compare the measured AC voltage and the AC voltage displayed on the inverter.
6. Check if the AC voltage shown on the inverter is no more than 5 V above or no more than 1 V
below the measured AC voltage.
18 STPTL-20-AST-RM-xx-10
Explanation
utility grid. Once the DC input voltage is sufficiently high and the grid-
connection conditions are met, the inverter starts operation.
An error message and event number appear in the display. Eliminate
the error (see the inverter manual).
SMA Solar Technology AG
Replacement Manual