ABB RD3M - Fail-safe Function

ON
7 8 9
FAIL SAFE
OUTPUT Relay
TRIP
10 11 12
7 8 9
10 11 12
FAULTON
OK
RD...
TR...
RD...
RD3M: 230-400 VAC
RD3M-48: 12-48 VAC/DC
7 8 9 10 11 12
Functions
Fail-safe → incorporated in the device (positive safety device) When no
current is input to the RD3 device, the output contacts number 10 11 12
will switch as shown in the figure below.
Contact status when the device is switched off:
18
ABB_76x88mm_RD3M_rev4.indd 18 19/09/11 11:02