DESIGNER’S HANDBOOK 4189350049C EN
Page 37 of 206
If the CAN bus cable is daisy-chained, the shield of the cable must be electrically connected beneath the strain
relief strip and must not be connected to CAN common!
Be aware, that the shield must not touch any other electrical parts or any metal parts around it. It is therefore
recommended to connect the two cable shields up against each other and cover the shield joint with a heat shrink
hose, before it is fixated below the cable strip. The two shields may be soldered together (with great care), but in
protected indoor panels, it should not be necessary.
4.5.2
Supply voltage monitoring:
The XDi has two supply voltage inputs, separated by diodes as shown below.
This allows the XDi to be supplied from two independent power sources. Each input is also protected by a polyfuse
that will disconnect the XDi unit in case of a short circuit in the internal power supply unit.
A single failure in one of the power source lines will not affect the XDi or the source located on the other side of the
separation diodes.
An internal single failure in one of the built-in separation diodes will not affect either the function of the XDi or the
rest of the system.
Each supply voltage input is equipped with an isolated voltage monitor circuit. This circuit will detect if the input
voltage drops below the minimum recommended supply voltage level.
This level is approximately 18 V DC.
In the product profile or via the menu, it is possible to activate supply voltage monitoring of one or both supply
voltage inputs.
If monitoring is active, a warning or alert pop-up will be presented on the display if the input voltage is too low (or
missing).
