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Functions and
characteristics
Introduction
Compact NSX trip units
With Micrologic electronic trip units,
Compact NSX stands out from the crowd.
Thanks to the new generation of sensors
and its processing capability, protection is
enhanced even further. It also provides
measurements and operating information.
Thermal-magnetic or electronic trip unit?
Thermal-magnetic trip units
protect against overcurrents and short-circuits using
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have become decisive factors and electronic trip units offering more advanced
protection functions combined with measurements are better suited to these needs.
Micrologic electronic trip units
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Thanks to digital electronics, trip units have become faster as well as more accurate
and reliable. Wide setting ranges make installation upgrades easier. Designed with
processing capabilities, Micrologic trip units can provide measurement information
and device operating assistance. With this information, users can avoid or deal more
effectively with disturbances and can play a more active role in system operation.
They can manage the installation, anticipate on events and plan any necessary
servicing.
Accurate measurements for complete protection
Compact NSX devices take advantage of the vast experience acquired since the
launch of Masterpact NW circuit breakers equipped with Micrologic trip units.
From 40 amperes on up to the short-circuit currents, they offer excellent
measurement accuracy. This is made possible by a new generation of current
transformers combining "iron-core" sensors for self-powered electronics and "air-
core" sensors (Rogowski toroids) for measurements.
The protection functions are managed by an ASIC component that is independent of
the measurement functions. This independence ensures immunity to conducted and
radiated disturbances and a high level of reliability.
Numerous security functions
Torque-limiting screws
The screws secure the trip unit to the circuit breaker. When the correct tightening
torque is reached, the screw heads break off. Optimum tightening avoids any risk of
temperature rise. A torque wrench is no longer required.
Easy and sure changing of trip units
All trip units are interchangeable, without wiring. Amechanical mismatch-protection
system makes it impossible to mount a trip unit on a circuit breaker with a lower
rating.
"Ready" LED for a continuous self-test
The LED on the front of the electronic trip units indicates the result of the self-test
runs continuously on the measurement system and the tripping release. As long as
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the Mitop release are operational. The circuit breaker is ready to protect. No need for
a test kit. Aminimum current of 15 to 50 A, depending on the device, is required for
this indication function.
A patented dual adjustment system for protection functions.
Available on Micrologic 5 / 6, the system consists of:
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maximum value
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screen, to within one ampere and a fraction of a second.
Coordinated tripping systems
Compact NSX detects faults even faster and its tripping time is reduced. It protects
the installation better and limits contact wear.
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This tripping system is completely independent of the trip unit.
Because it directly actuates the mechanism, it precedes the trip unit by a few milliseconds.
559E1100.indd
version: 1.0