Protecting The Drive Against Ground Faults; Residual Current Device Compatibility; Implementing The Emergency Stop Function - ABB ACS480-04-09A8-1 Hardware Manual

60 Guidelines for planning the electrical installation
1. If there is double or reinforced insulation between the sensor and the live parts of
the motor: You can connect the sensor directly to the analog/digital input(s) of the
drive. See the control cable connection instructions. Make sure that the voltage
does not exceed the maximum allowed voltage over the sensor.
2. If there is basic insulation between the sensor and the live parts of the motor: You
can connect the sensor to the analog/digital input(s) of the drive. All other circuits
connected to the digital and analog inputs (typically extra-low voltage circuits) must
be:
• protected against contact, and
• insulated with basic insulation from other low-voltage circuits. The insulation must
be rated for the same voltage level as the drive main circuit.
Note: Extra-low voltage circuits (for example, 24 V DC) typically do not meet these
requirements.
Make sure that the voltage does not exceed the maximum allowed voltage over the
sensor.
As an alternative, you can connect the sensor with basic insulation to the
analog/digital input(s) of the drive, if you do not connect any other external control
circuits to the drive digital and analog inputs.
3. You can connect a sensor to a digital input of the drive via an external relay. The
sensor and the relay must form a double or reinforced insulation between the motor
live parts and the digital input of the drive. Make sure that the voltage does not
exceed the maximum allowed voltage over the sensor.

Protecting the drive against ground faults

The drive is equipped with an internal ground fault protective function to protect the unit
against ground faults in the motor and motor cable. This function is not a personnel
safety or a fire protection feature. See the firmware manual for more information.
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Residual current device compatibility

The drive is suitable to be used with residual current devices of Type B.
Note: As standard, the drive contains capacitors connected between the main circuit
and the frame. These capacitors and long motor cables increase the ground leakage
current and may cause nuisance faults in residual current devices.

Implementing the Emergency stop function

For safety reasons, install the emergency stop devices at each operator control station
and at other operating stations where emergency stop may be needed. Design the
emergency stop according to the applicable standards.
You can use the Safe torque off function of the drive to implement the Emergency stop
function.