Nortel DMS-100 Series Maintenance Manual page 37

Figure 8 OPM grounding network (NT8X01AB OPM-640/NT8X01BB OPM-256)
Frame gnd
bay 0
Master ground bar
Frame GND
bay 1
Cabinet
GND
OPM principal
(earth) GND
Protector
block
GND
Cabinet
GND
(mgb)
DMS-100 Family OPM Maintenance Manual ISN07 (TDM)/SN07 (DMS) and up
OPM maintenance summary 1-21
Logic
GND
Internal ground bar
Outside
plant
cables (4)
ac
GND
Cabinet
GND
(IGB)