Checking The Pv System For Ground Faults - SMA SUNNY TRIPOWER CORE1-US Serie Instrucciones De Uso

6 Troubleshooting
6.3

Checking the PV System for Ground Faults

Danger to life due to electric shock when touching live system components in
case of a ground fault
If a ground fault occurs, parts of the system may still be live. Touching live parts and cables
results in death or lethal injuries due to electric shock.
• Disconnect the product from voltage sources and make sure it cannot be reconnected
before working on the device.
• Touch the cables of the PV array on the insulation only.
• Do not touch any parts of the substructure or frame of the PV array.
• Do not connect PV strings with ground faults to the inverter.
• Ensure that no voltage is present and wait five minutes before touching any parts of the PV
system or the product.
Destruction of the measuring device due to overvoltage
• Only use measuring devices with a DC input voltage range of 1000 V or higher.
Procedure:
In order to check the PV system for ground faults, perform the following actions in the prescribed
order. The exact procedure is described in the following sections.
• Check the PV system for ground faults by measuring the voltage.
• If the voltage measurement was not successful, check the PV system via insulation resistance
measurement for ground faults.
Test by Measuring the Voltage
Proceed as follows to check each string in the PV system for ground faults.
If PV module switches are installed that comply with the SunSpec communication signal for Rapid
Shutdown systems, the voltage measurement can be taken as described. After the inverter is
disconnected, the PV module switches no longer receive the "Permission-to-Operate" signal and
output a standby voltage instead of the module voltage as per their specification. The respective
string voltage can be determined via the standby voltage. When calculating the ground fault
location, the module voltage must be replaced with the standby voltage as specified by the PV
module switch.
Procedure:
1.
Danger to life due to high voltages
• Disconnect the inverter from any voltage sources (see the inverter installation manual).
56 STP33-62-US-41-BA-en_es-10
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