Siemens SENTRON - Page 68

68
Appendix
A
Permissible protective measures:
• Residual current protective devices
• Overcurrent protective devices
Where residual current protective devices are used different maximum permissible
grounding resistances are specied for Type AC and Type A as a function of the
rated residual current to meet the disconnection conditions (see table A1).
Rated residual
current I
Δn
Maximum permissible grounding resistance
at a maximum permissible touch voltage of
50 V 25 V
10 mA 5.000 Ω 2.500 Ω
30 mA 1.660 Ω 830 Ω
100 mA 500 Ω 250 Ω
300 mA 170 Ω 85 Ω
500 mA 100 Ω 50 Ω
1 A
50 Ω 25 Ω
The specications of section 4.4.3 shall be observed for SIQUENCE Type B and
Type B+ universal current-sensitive RCCBs if the equipment used has different
frequency components in the possible residual current.
Table A1: Maximum permissible grounding resistances as a function of I
Δn