Beckhoff EL1052 Documentation page 34

Mounting and wiring
For devices with Ethernet connectors
Not for connection to telecommunication circuits.
Basic principles
Two UL certificates are met in the Beckhoff EtherCAT product range, depending upon the components:
1. UL certification according to UL508. Devices with this kind of certification are marked by this sign:
2. UL certification according to UL508 with limited power consumption. The current consumed by the de-
vice is limited to a max. possible current consumption of 4 A. Devices with this kind of certification are
marked by this sign:
Almost all current EtherCAT products (as at 2010/05) are UL certified without restrictions.
Application
If terminals certified with restrictions are used, then the current consumption at 24 V
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.
A voltage source complying with NEC class 2 may not be connected in series or parallel with another
NEC class 2compliant voltage supply!
These requirements apply to the supply of all EtherCAT bus couplers, power adaptor terminals, Bus
Terminals and their power contacts.
34 Version: 1.1
must be limited
DC
EL1052, EL1054