Protecting The Motor Against Thermal Overload; Protecting The Drive Against Ground Faults; Residual Current Device Compatibility; Implementing The Emergency Stop Function - ABB ACS880-07CLC Hardware Manual

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Protecting the motor against thermal overload

According to regulations, the motor must be protected against thermal overload and the
current must be switched off when overload is detected. The drive includes a motor thermal
protection function that protects the motor and switches off the current when necessary.
Depending on a drive parameter value, the function either monitors a calculated temperature
value (based on a motor thermal model) or an actual temperature indication given by motor
temperature sensors. The user can tune the thermal model further by feeding in additional
motor and load data.
The most common temperature sensors are:
• motor sizes IEC180...225: thermal switch, eg. Klixon
• motor sizes IEC200...250 and larger: PTC or Pt100.
See the firmware manual for more information on the motor thermal protection, and the
connection and use of the temperature sensors.

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 in TN (grounded) networks. This is not
a personnel safety or a fire protection feature. The ground fault protective function can be
disabled with a parameter, refer to the firmware manual.
An optional ground fault monitoring device (+Q954) is available for IT (ungrounded) systems.
The option includes a ground fault indicator on the drive cabinet door.
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Residual current device compatibility

The drive is suitable to be used with residual current devices of Type B.
Note:
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 fault
current circuit breakers to function.

Implementing the emergency stop function

You can order the drive with a category 0 or category 1 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.
Note:
Pressing the stop key
of the drive from position "1" to "0" does not generate an emergency stop of the motor or
separate the drive from dangerous potential.
See the appropriate emergency stop user's manual for the wiring, start-up and operation
instructions.
Option code
+Q951 Emergency stop, stop category 0 (using main contactor/breaker)
Emergency stop, stop category 0 (using main contactor/breaker) with
+Q951+Q984
push button monitoring
Guidelines for planning the electrical installation 77
on the control panel of the drive, or turning the operating switch
User's manual
Manual code
(English)
3AXD50000207848