iCU-DC / iCU-EC Operating Instructions
Page - 6
▪
Warning! High earth leakage current (ground discharge current,
protection conductor current).
Before connecting to the AC supply
network, it is necessarily required an
additional protective
grounding
. Before connecting the CNC controller to the AC supply
network, an
additional protective grounding
(cross section: 2.5 mm
2
or 4 mm
2
, see below) has to be connected! Before the electrical start-
op of the controllers a protective grounding of 2.5 mm
2
(protected
installation) or a protective conductor of 4 mm
2
(unprotected
installation) has to be connected durably to the marked clamping point
at the back of the housing where the cross section of the protective
grounding shall not be less than 10 mm
2
copper or 16 mm
2
aluminum
has (e.g. electrical distribution of the building). Please instruct an
electrician with these implementation. When using the Residual
Current circuit Device (RCD) for line fuses/fault current delimitation: Do
not use an RCD with AC characteristics. Using a frequency inverter
and choppered power stages in the power units may cause
superimposed AC fault units with pulsating direct current and direct
current apart from AC fault currents. Please consult your electrician.
▪
The term leakage is understood here as grounding discharge
current. This is defined in the standard EN 60204-1:2006 section
8.2.8, note 1
▪
If the CNC machine (ideal) is set up isolated from the reference
potential, the grounding discharge current is equal to the
protective grounding stream.
