Appendix 10.5 Mains Connections 10.5.1 Connection socket of ISG3410-400V Allocation of the CEE socket Pin name Pin designation Wire colour L1 Phase L1 Brown L2 Phase L2 Black/ grey L3 Phase L3 Black N Neutral Blue PE Ground Green-yellow The nominal voltages between the phases are 3x400V (-10/ +10%) Measurement Voltage (VAC) between the pins N  L1 PE  L1 230 N  L2 PE  L2 230 N  L3 PE  L3 230 L1  L2 400 L1  L3 400 L2  L3 400 Further hints:  Connecting the protected earth PE and connecting the neutral N is essential!  If an earth-leakage circuit breaker (GFI, GFCI) is used for the protection of the CEE-socket, it must be 4-polar. October 2015 ISG3410 53