Testboy TV 455VDE-tester Testboy TV 455 Manuale Utente

 
It can happen that a dangerous voltage is applied to the PE wire or other accessible 
metal parts. This is a very dangerous situation since the PE wire and MPEs are 
considered to be earthed. An often reason for this fault is incorrect wiring (see examples 
below).  
When touching the TEST key in all functions that require mains supply the user 
automatically performs this test. 
 
Examples for application of PE test terminal