ABB ACS580-04, Руководство по оборудованию

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Implementing motor and motor cable short-circuit and
thermal overload protection
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Protecting the motor and motor cable in short-circuits
The drive protects the motor cable and motor in a short-circuit situation when:
• the motor cable is sized correctly
• the motor cable type complies with the motor cable selection guidelines by ABB
• the cable length does not exceed the allowed maximum length specified for the
drive
• the setting of parameter 99.10 Motor nominal power in the drive is equal with the
value given on the motor rating plate.
The electronic power output short-circuit protection circuitry meets the requirements
of IEC 60364-4-41 2005/AMD1.
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Protecting the motor cables against thermal overload
The drive protects the motor cables against thermal overload when the cables are
sized according to the nominal output current of the drive. No additional thermal
protection devices are needed.
WARNING!
If the drive is connected to multiple motors, use a separate overload protection
for each motor cable and motor. The drive overload protection is tuned for the
total motor load. It may not detect an overload in one motor circuit only.
North America: The local code (NEC) requires an overload protection and a
short-circuit protection for each motor circuit. Use, for example:
• manual motor protector
• circuit breaker, contactor and overload relay or
• fuses, contactor and overload relay.
￭
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 motor thermal protection model supports thermal memory retention and speed
sensitivity. The user can tune the thermal model further by feeding in additional motor
and load data.
The most common temperature sensor types are PTC or Pt100.
For more information, see the firmware manual.
Guidelines for planning the electrical installation 91