Omron NT620S Operation Manual page 41

Installation
2-2-3 Grounding
NT620S/
620C
Class 3 grounding
(grounding resistance
is 100 Ω or less)
Grounding for individual equipment:...Correct
Caution
Note
28
The NT620S/620C has a GR terminal.
The GR terminal is the earth grounding terminal; connect the special grounding
2
wire (2 mm or larger) to this terminal to prevent electric shock. Carry out class 3
grounding (grounding resistance must be less than 100 Ω).
Grounding wire length should be less than 20 m.
Note that if grounding wire is used in common with other equipment, or if it is con-
nected to a beam of a building, for example, the NT620S/620C might be adverse-
ly affected by this grounding.
Other NT620S/
equipment 620C
Grounding common to several pieces of equipment:...Incorrect
Carry out grounding correctly in order to prevent incorrect operation due to
noise.
Carry out class 3 grounding, connecting the grounding wire to the GR terminal.
If grounding is not carried out there will be a danger of electric shock.
Other
NT620S/
equipment
620C
Section 2-2
Other
equipment