4.4.2  Optional Voltage Detection System 
VDS  
The low voltage control panel of a switch panel may be 
fitted with a voltage sensor and indicator. These may 
vary in functionality but the standard offering, if fitted, 
provides the following functionality.  
Voltage indicator 
A voltage indicator is an indicator with three Light 
Emitting Diodes (LEDs) and three socket contacts L1, L2 
and L3. It is connected via a signal cable to a voltage 
sensor, which is located on the cable section of the panel 
to be monitored. Each LED monitors one phase. The 
LEDs light up if a voltage is present on the phases 
monitored. If they are dead the LEDs do not light up  
 
For details refer to the specific user manual for the 
device fitted.