ABB ACS580-04 - Circuit Breakers; Protecting the Drive and Input Power Cable in Short-Circuits; Protecting the Motor against Overload Without Thermal Model or Temperature Sensors

￭ Protecting the motor against overload without thermal model or
temperature sensors
Motor overload protection protects the motor against overload without using motor
thermal model or temperature sensors.
Motor overload protection is required and specified by multiple standards including
the US National Electric Code (NEC) and the common UL/IEC 61800-5-1 standard in
conjunction with UL/IEC 60947-4-1. The standards allow for motor overload protection
without external temperature sensors.
The protection feature of the drive allows the user to specify the class of operation
in the same manner as the overload relays are specified in standards UL/IEC 60947-4-1
and NEMA ICS 2.
The motor overload protection supports thermal memory retention and speed
sensitivity.
For more information, see drive firmware manual.
Protecting the drive and input power cable in short-circuits
Protect the drive (1) with fuses (a) and the input cable with fuses (b) or a circuit breaker.
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M
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b a
1
Size the fuses or the circuit breaker according to local regulations for the input cable
protection. Select the fuses for the drive according to the instructions given in the
technical data. The fuses for the drive protection will restrict drive damage and prevent
damage to adjoining equipment in case of a short-circuit inside the drive.
Note: If the fuses for the drive protection are placed at the distribution board and the
input cable is dimensioned according to the nominal input current of the drive given
in the technical data, the fuses protect also the input cable in short-circuit situations,
restrict drive damage and prevent damage to adjoining equipment in case of a
short-circuit inside the drive. No separate fuses for the input cable protection are
needed.
￭ Circuit breakers
The protective characteristics of circuit breakers depend on the type, construction
and settings of the breakers. There are also limitations pertaining to the short-circuit
capacity of the supply network. Your local ABB representative can help you in selecting
the breaker type when the supply network characteristics are known.
WARNING! Due to the inherent operating principle and construction of circuit
breakers, independent of the manufacturer, hot ionized gases can escape from
the breaker enclosure in case of a short-circuit. To ensure safe use, pay special
attention to the installation and placement of the breakers. Obey the
manufacturer’s instructions.
92 Guidelines for planning the electrical installation