Cabling

UL requirements

If terminals certified with restrictions are used, then the current consumption at 24 VDC must be limited accordingly by means of supply
• from an isolated source protected by a fuse of max. 4 A (according to UL248) or
• from a voltage supply complying with NEC class 2.

An NEC class 2 voltage source must not be connected in series or parallel with another NEC class 2 voltage source! These requirements apply to the supply of all Bus Couplers, power supply terminals, Bus Terminals and their power contacts.

UL requirements

In order to comply with UL requirements, the EtherCAT components must not be connected to unlimited voltage sources!