MΩ
Insulation Resistance
Table 64 test voltages and minimum values.
Values
SELV/PELV: 250 V DC, min 0.5 MΩ. Up to 500 V (including 230/400 V): 500 V DC, min 1 MΩ. Above 500 V: 1000 V DC, min 1 MΩ. Readings below 2 MΩ should be investigated.
Method
Disconnect or protect sensitive equipment (SPDs, electronic devices). Test L+N to E; for circuits with sensitive equipment connected, a 250 V test L+N to E is permitted.
Key regulations
643.3Table 64