Components Connected To Digital/Analog Inputs - ABB ACS 601 Hardware Manual

Appendix C – IEC Installation
Components
Connected to Digital/
Analog Inputs
C-4 ACx=ACS/ACC/ACP
the grounding rail next to the NIOC/NIOCP board.
WARNING! IEC 664 requires double or reinforced insulation between
live parts and the surface of accessible parts of electrical equipment
which are either non-conductive or conductive but not connected to the
ground (PE).
To fulfil this requirement, the connection of a thermistor (and other
similar components) to the digital inputs of ACx 600 can be
implemented in three alternate ways:
1. There is double or reinforced insulation between the thermistor and
live parts of the motor.
2. Circuits connected to all digital and analog inputs of the ACx 600
are protected against contact, and
insulated with basic insulation (the same voltage level as the
converter main circuit) from other low voltage circuits.
3. An external thermistor relay is used. The insulation of the relay must
be rated for the same voltage level as the converter main circuit.
ACS/ACC/ACP 601 Drives