Power Supply, Potential Groups; Fig. 35 Potential Diagram Ekxxxx - Beckhoff EK1101 Documentation

Mounting and wiring
4.10

Power supply, potential groups

Bus Coupler power supply
The Bus Couplers require a 24 V DC supply for their operation. The connection is made by means of the
upper spring-loaded terminals labelled 24 V and 0 V. The supply voltage is used by the Bus Coupler
electronics and for direct voltage generation for the E-bus. The voltage generation for the E-bus takes place
in a DC/DC converter without electrical isolation.
The EK1xxx units supply the E-bus with max. 2,000 mA E-bus current. Power feed terminals are to be
inserted if the added terminals require more current.
Input for power contacts
The bottom six connections with spring-loaded terminals can be used to feed the supply for the peripherals.
The spring-loaded terminals are joined in pairs to a power contact. The feed for the power contacts has no
connection to the voltage supply for the Bus Coupler. The design of the feed permits voltages of up to 24 V.
The assignment in pairs and the electrical connection between feed terminal contacts allows the connection
wires to be looped through to various terminal points. The current load via the power contacts may not
permanently exceed 10 A; the supply line must therefore be protected by a 10 A fuse (slow-blow).
Power contacts
On the right hand face of the Bus Coupler there are three spring contacts for the power contact connections.
The spring contacts are hidden in slots so that they can not be accidentally touched. By attaching a Bus
Terminal the blade contacts on the left hand side of the Bus Terminal are connected to the spring contacts.
The tongue and groove guides on the top and bottom of the Bus Coupler and of the Bus Terminals
guarantees that the power contacts mate securely.
The current load of the power contacts may not permanently exceed 10 A.
Electrical isolation
The bus couplers operate by means of three independent potential groups. The supply voltage feeds the E-
bus electronics in the bus coupler and the E-bus itself, which are electrically isolated. The supply voltage is
also used to generate the operating voltage for the fieldbus.
Note: All the Bus Terminals are electrically isolated from the E-bus. The E-bus is thus electrically isolated
from everything else.
Fig. 35: Potential diagram EKxxxx
50 Version: 3.6 EK110x, EK15xx