Porter-Cable PCB222TS Instruction Manual page 9

The adapter (fig. ) has a rigid lug extending from it that
MUST be connected to a permanent earth ground, such
as a properly grounded receptacle box.
cAuTION
!
In all cases, make certain the receptacle is properly
grounded. If you are not sure, have a qualified
electrician check the receptacle.
Fig. 1
Three-Pronged Plug
Properly Grounded
Three-Pronged Receptacle
Fig. 2
Grounding Lug
Adapter
Grounding Prong
Make sure this is
connected to a
known ground.
Two-Pronged
Receptacle
9