BECKHOFF CU8860-0000 - Manual (Page 11)

Installation
CU8860-0000 9
3.3 Power Supply
The USB-Extender-Rx CU8860 can be powered by an additional power supply (X10). If a USB device needs more
than 100 mA the additional power supply must be connected. The pins have to be connected as shown in the
picture below.
3.3.1 UL requirements
Danger
For the compliance of the UL requirements the USB-Extender-Rx should only be supplied
 by a 24 V
DC
supply voltage, supplied by an isolating source and protected by means
of a fuse (in accordance with UL248), rated maximum 4 Amp.
 by a 24 V
DC
power source, that has to satisfy NEC class 2.
A class 2 power supply shall not be connected in series or parallel with another
(class 2) power source!
To meet the UL requirements, the USB hub CU8800-0000 must not be connected to
unlimited power sources!