Electrical Distribution Protection
Presentation
MicroLogic trip units are designed to provide protection against overcurrents and ground-fault currents.
Description
When choosing protection characteristics, take into account:
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Overcurrents (overloads and short-circuits) and potential ground-fault currents.
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Conductors that need protection.
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Coordination and selectivity between the devices.
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The presence of harmonic currents.
Protection characteristics can be represented on a trip curve that shows the circuit breaker trip time as a function of the measured current and protection settings. Protection settings are indexed on the rated current In of the MicroLogic trip unit.
Rated Current In
The protection setting ranges depend on the rated current In, defined by the sensor plug inserted in the MicroLogic trip unit.
MicroLogic 2.0 Trip Unit
MicroLogic 2.0 trip units provide:
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Long-time overcurrent protection (Ir)
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Instantaneous overcurrent protection (Isd)
The protection functions of MicroLogic 2.0 trip units operate without an auxiliary power supply. The trip unit is powered by the current flowing through the circuit breaker.
MicroLogic 5.0 Trip Unit
MicroLogic 5.0 trip units provide:
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Long-time overcurrent protection (Ir)
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Short-time overcurrent protection (Isd)
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Instantaneous overcurrent protection (Ii)
The protection functions of MicroLogic 5.0 trip units operate without an auxiliary power supply. The trip unit is powered by the current flowing through the circuit breaker.
MicroLogic 6.0 Trip Unit
MicroLogic 6.0 trip units provide:
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Long-time overcurrent protection (Ir)
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Short-time overcurrent protection (Isd)
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Instantaneous overcurrent protection (Ii)
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Ground-fault protection (Ig)
The protection functions of MicroLogic 6.0 trip units operate without an auxiliary power supply. The trip unit is powered by the current flowing through the circuit breaker.