MicroLogic Trip Units–Overview
True RMS Current Sensing
The sensing system responds to the flow of current through the circuit breaker. Electronic trip circuit breakers are limited to ac systems because the electronic trip system uses current transformers to sense the current. The MicroLogic trip unit samples the current waveform to provide true RMS protection through the 15th harmonic.
This true RMS sensing gives accurate values for the magnitude of a non-sinusoidal waveform. Therefore, the heating effects of harmonically distorted waveforms are accurately evaluated.
The MicroLogic H trip unit provides additional sampling of the waveforms to measure and provide waveform capture of harmonic distortion to the 31st harmonic.
MasterPacT universal power circuit breakers use MicroLogic electronic trip systems to sense overcurrents and trip the circuit breaker. The MicroLogic basic trip unit is standard and all MasterPacT circuit breakers can be equipped with the optional MicroLogic trip systems listed below:
— MicroLogic Basic Trip Unit (standard).
-
2.0 basic protection (LS0, IEC)
-
3.0 basic protection (LI, UL®/ANSI)
-
5.0 selective protection (LSI)
— MicroLogic A: Trip Unit with Ammeter.
-
2.0A basic protection (LS0, IEC)
-
3.0A basic protection (LI, UL/ANSI)
-
5.0A selective protection (LSI)
-
6.0A selective protection with ground-fault protection for equipment (LSIG)
— MicroLogic P: Trip Unit with Power Metering.
-
5.0P selective protection (LSI)
-
6.0P selective protection with ground-fault protection for equipment (LSIG)
— MicroLogic H: Trip Unit with Harmonic Metering.
5.0H selective protection (LSI)
6.0H selective protection with ground-fault protection for equipment (LSIG)
|
MicroLogic 3.0 and 5.0 Basic Trip Units |
MicroLogic 3.0A, 5.0A and 6.0A Trip Units |
|
MicroLogic 5.0P and 6.0P Trip Units |
MicroLogic 5.0H and 6.0H Trip Units |
MicroLogic Trip Unit Features
|
MicroLogic Trip Unit (X = Standard Feature O = Available Option) |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Standard |
Ammeter |
Power |
Harmonics |
||||||||
|
Feature |
2 |
3 |
5 |
2.0A |
3.0A |
5.0A |
6.0A |
5.0P |
6.0P |
5.0H |
6.0H |
|
LI |
— |
X |
— |
— |
X |
— |
— |
— |
— |
— |
— |
|
LS0 |
X |
— |
— |
X |
— |
— |
— |
— |
— |
— |
— |
|
LSI |
— |
— |
X |
— |
— |
X |
— |
X |
— |
X |
— |
|
LSIG/Ground-Fault Trip* |
— |
— |
— |
— |
— |
— |
X |
— |
X |
— |
X |
|
— |
— |
— |
— |
— |
— |
— |
X |
— |
X |
— |
|
|
— |
— |
— |
— |
— |
— |
— |
— |
X |
— |
X |
|
|
Adjustable Rating Plugs |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
|
True RMS Sensing |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
|
UL Listed |
X |
X |
— |
X |
X |
X |
X |
X |
X |
X |
|
|
Thermal Imaging |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
|
Phase-Loading Bar Graph |
— |
— |
— |
X |
X |
X |
X |
X |
X |
X |
X |
|
LED for Long-Time Pick-Up |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
X |
|
LED for Trip Indication |
— |
— |
— |
X |
X |
X |
X |
X |
X |
X |
X |
|
Digital Ammeter |
— |
— |
— |
X |
X |
X |
X |
X |
X |
X |
X |
|
Zone-Selective Interlocking* |
— |
— |
— |
X |
X |
X |
X |
X |
X |
X |
|
|
Communications |
— |
— |
— |
O |
O |
O |
O |
X |
X |
X |
X |
|
LCD Dot Matrix Display |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Advanced User Interface |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Protective Relay Functions |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Neutral Protection1 |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Contact Wear Indication |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Incremental Fine Tuning of Settings |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Selectable Long-Time Delay Bands |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Power Measurement |
— |
— |
— |
— |
— |
— |
— |
X |
X |
X |
X |
|
Power Quality Measurements |
— |
— |
— |
— |
— |
— |
— |
— |
— |
X |
X |
|
Waveform Capture |
— |
— |
— |
— |
— |
— |
— |
— |
— |
X |
X |