Leakage Current From The Inverter Housing To The Grounding Connection - HEIDENHAIN TNC 410 M Technical Manual

4.3 Leakage Current from the Inverter Housing to the Grounding Connection

April 2007
Leakage Current from the Inverter Housing to the Grounding Connection
HEIDENHAIN inverters are electronic equipment with a leakage current
greater than 3.5 mA (from the housing to ground). Therefore a sticker with the
following warning is on the inverter components:
Ableitstrom > 3.5 mA
Potenzialausgleich anschließen!
Leakage current > 3.5 mA
Connect potential equalization!
Danger
Since persons must not be exposed to leakage currents greater than
3.5 mA, the following must be ensured for protective grounding according
to IEC 61800-5-1 "Adjustable Speed Electric Power Drive Systems"):
Power connection with clamping:
The cable for the grounding connection must have a line cross section
greater than half that of an external line, but at least (≥) ∅ 10 mm
Power connection with connector:
A second grounding conductor with a line cross section greater than half
that of an external line, but at least (≥) ∅ 10 mm
grounding conductor of the connector, must be firmly grounded.
This means that in both cases a clamped grounding connection must be
installed.
If more than one piece of equipment is connected to the same grounding
connection, the leakage currents add up. Therefore the commissioner must
ensure that the grounding connection is of sufficient low-impedance.
Danger
HEIDENHAIN recommends placing a sign on the outside of the electrical
cabinet with a warning and a connection recommendation for the
grounding conductor.
2
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2
, along with the
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