Fronius Symo 3.0-3-S Serviceanleitung Seite 115

Measurement Test voltage
Primary -> at least the max. DC input voltage of the device,
Ground however max. 1000 V
Secondary -> >= 500 V
Ground
Key: Primary = DC (DC+ and DC-) | Secondary = AC (L and N) | Ground = PE
The insulation resistance test must be conducted between the following points on both
the inverter and the wall bracket.
However, on the DC disconnector the measurement should only be taken on the screws
and not on the contacts.
Ground to AC / Ground to DC
1 Measuring instrument
2 Inverter
9 Measuring line
WARNING!
An electric shock can be fatal. Capacitors can charge during the insulation resis-
tance measurement.
After carrying out the insulation resistance test, check that all tested potentials are de-
energized before continuing with the safety inspection. Alternatively, the capacitors can
be discharged by short-circuiting the tested potentials or via the discharge function on
the insulation tester.
Capacitor discharge time is at least 5 minutes.
Examples for measuring the insulation resistance
Limit
value
>= 1 MW
>= 1 MW
115