Connection Diagram Xts-Infeed - Beckhoff XTS Startup Manual

Technical description
6.1.2

Connection diagram XTS-Infeed

Circuit diagram 48 V negative not grounded:
Circuit diagram 48 V minus grounded:
20
PE connection port
of the module body
48V
GND
24V
EtherCAT
line
Do not ground the negative side of the 48V DC Bus
Power Supply! The adjacent diagram describes the
current distribution in the individual conductors. Inside
the module the negative 24V and negative 48V
cables are connected together. If the 48V minus is
not grounded the current for each circuit remains on
its conductors. The current for the 24V control power
remains on the 0.75mm wires to and from the
module. The current for the 48V power remains on
the 2.5mm 48V wires to and from the module. The
grounding of the DC Bus circuit is not necessary. The
EN60204-1 Standard chapter 9.4.3.1 (ground faults)
describes that the control circuits must be grounded
to ensure a machine cannot start with a broken cable.
Load circuits are not affected.
If the negative side of the 48V power supply is
grounded, the following situation occurs as described
by the adjacent diagram. Again, the -48V and -24V
lines are connected internally in the modules. If the
negative side of the 48V power supply is also
grounded, -24V wire (0.75mm) and the -48V wire
(2.5mm) act in parallel for the return path. This will
overload the -24V (0.75mm) wire. The +48V wire
(2.5mm) will carry the 48V load circuit current to the
module, the +24V wire (0.75mm) will carry the 24V
Control circuit current to the module. On the return
side, the -24V (0.75mm) wire will carry half of the
sum of the 48V load circuit current and the 24V
control circuit current. The -48V (2.5mm) wire will
carry the other half of the sum of the currents. The
0.75mm wire does have a slightly higher resistance
(0.042Ohm/m) than the 2.5mm (0.013Ohm/m) wire
but the difference is so small it can be omitted.
Version: 1.2 eXtended Transport System Start-Up