Calculating the insulation resistance
The expected total resistance of the PV system or of an individual string can be calculated using the following formula:
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.
Also see: