Checking The Ac Line Voltage; Checking The Internal Voltage Supply; Checking The Grid Monitoring - SMA SUNNY CENTRAL 500CP XT Installation Manual

15 Commissioning
4. Measure the DC voltage for each non-grounded pole to ground and record in the commissioning report. Use the
connection lugs of the ungrounded terminal and the grounding busbar as measuring points.
☑ Voltage drop can be measured.
✖ Voltage drop cannot be measured?
A ground fault is present.
• Eliminate the ground fault.

15.3.2 Checking the AC Line Voltage

1. Using a rotating field instrument, measure whether a right-rotating magnetic field is connected at the AC connection
lugs. If a left-rotating magnetic field is connected, two line conductors have been incorrectly connected.
• Swap the connections L1 and L3.
2. Check whether the AC voltage is approximately the same as the nominal voltage of the Sunny Central. Measure the
AC voltage between the terminals at the AC connection lugs and record in the commissioning report.
If the AC voltage differs significantly from the nominal voltage of the Sunny Central, the transformation ratio of the
MV transformer must be adjusted by a duly authorized person.

15.3.3 Checking the Internal Voltage Supply

1. Using the rotating field instrument, measure to establish whether a right-rotating magnetic field is connected at the
supply voltage circuit breaker. Use the measuring points on the circuit breaker of the supply voltage.
If a left-rotating magnetic field is connected, two line conductors have been incorrectly connected.
• Swap the connections L1 and L3.
2. Measure the AC voltages between the terminals on the circuit breaker of the supply voltage and record the values
in the commissioning report. Use the measuring points on the circuit breaker of the supply voltage.
☑ The voltage between the line conductors is in the range 360 V to 460 V. The voltage between line conductor and
neutral conductor or grounding conductor is in the range 207 V to 264 V. The voltage between grounding
conductor and neutral conductor is 0 V.

15.4 Checking the Grid Monitoring

Parameters for grid monitoring
The Sunny Central is supplied with the grid monitoring parameters set according to the requirements in the
respective country.
The grid operator may request settings of the grid monitoring parameters which differ from these default settings.
Grid monitoring parameters can be adjusted via the user interface. Details of how to adjust the grid monitoring
parameters can be found in the Sunny Central operating manual.
Additional material required for tests:
☐ 1 function generator
Procedure:
1. Ensure that the motor-protective circuit-breaker of the grid monitoring is switched off.
70 SCCPXT-IA-D7-en-42
SMA Solar Technology AG
Installation Manual