ABB ACH550-01 User Manual page 267

ACH550 User's Manual
WARNING! IEC 60664 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 protective earth.
To fulfil this requirement, connect a thermistor (and other similar
components) to the drive's control terminals using any of these
alternatives:
• Separate the thermistor from live parts of the motor with
double reinforced insulation.
• Protect all circuits connected to the drive's digital and analog
inputs. Protect against contact, and insulate from other low
voltage circuits with basic insulation (rated for the same
voltage level as the drive's main circuit).
• Use an external thermistor relay. The relay insulation must be
rated for the same voltage level as the drive's main circuit.
The figure below shows the thermistor relay connection. At the
motor end the cable shield should be earthed through a 10 nF
capacitor. If this is not possible, leave the shield unconnected.
Thermistor
relay
For other faults, or for anticipating motor overheating using a
model, see
Parameter listing and descriptions
T
Motor
Group 30: FAULT
I/O board
DI
+24 VDC
FUNCTIONS.
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