SMA 15000TL, Руководство по эксплуатации

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10 Troubleshooting SMA Solar Technology AG
Operating manual STP15-25TL-30-BE-en-17 71
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100 V 100 V 100 V 100 V 100 V
V = 200 V
1
V = 300 V
2
Test by Measuring the Insulation Resistance
If the voltage measurement does not provide sufficient evidence of a ground fault, the insulation
resistance measurement can provide more exact results.
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Figure 9: Schematic diagram of the measurement
Calculating the insulation resistance
The expected total resistance of the PV system or of an individual string can be calculated
using the following formula:
total
The exact insulation resistance of a PV module can be obtained from the module manufacturer
or the datasheet.
For the resistance of a PV module an average value can be assumed: for thin-film PV modules
approximately 40 MOhm and for polycrystalline and monocrystalline PV modules
approximately 50 MOhm per PV module (for further information on calculating the insulation
resistance see the Technical Information "Insulation Resistance (Riso) of Non-Galvanically
Isolated PV Systems" at www.SMA-Solar.com).