The following ground systems are provided for the machine :
D Signal grounding
Signal grounding supplies a reference potential (0 V) for electrical
D Grounding for protection
Grounding for protection is performed for safety reasons as well as to
shield against external and internal noise. This type of grounding
includes, for example, the equipment frames, cases and panels of
units, and the shielding on interface cables connecting the equipment.
D Protective grounding (PE)
Protective grounding (PE) is performed to connect protection grounds
provided for equipment or between units to ground together at one
point as a grounding system.
PE (ground plate of cabinet)
Cabinet on machine side
Path for grounding
Path for protective grounding (PE)
D The ground resistance in protective grounding (PE) must be 100 Ω or
less (type D grounding).
D The cable used for protective grounding (PE) must be of a sufficient
cross section to allow current to flow safely into protective ground
(PE) if an accident such as a short–circuit occurs. (Generally, a cross
section equal to or greater than that of the AC power cable is required.)
D The cable connected to protective ground (PE) must be incorporated
into the AC power wire such that power cannot be supplied with the
ground wire disconnected.
Notes on grounding