MicroLogic X Control Unit

The MicroLogic X control unit is suitable for different systems of voltage, three or four wires up to 600 Vac, 50/60 Hz and for grounded systems.

Model	Protection	Catalog Number	Additional Features
MicroLogic 3.0 X	LI: Long time + Instantaneous	LV848815FS	Digital Modules
MicroLogic 5.0 X	LSI: Long-time + Short-time + Instantaneous	LV847609FS	Digital Modules
MicroLogic 6.0 X	LSIG: Long-time + Short-time + Instantaneous + Ground-fault	LV847608FS	Digital Modules

Long-time protection protects the conductors against overload currents. It is based on the true RMS current and is implemented independently for each phase and the neutral.

Thermal imaging is integrated into the long-time protection that models the heating and cooling cycles of the conductors.

Short-time protection protects the installation against phase-to-phase, phase-to-neutral and phase-to-ground short circuits.

It is based on the true RMS current. It includes two characteristics depending on the status of the I²t setting:

• When I²t is OFF, a definite time characteristic is selected.
  The protection trips with the time delay tsd as soon as the setting current Isd is exceeded.

• When I²t is ON, an inverse time characteristic is selected.
  The protection operates with the inverse time characteristic up to 10 x Ir and with a definite time characteristic above 10 x Ir.

Short-time adjustment may be used to improve selective coordination for the electrical system. Zone-selective interlocking (ZSI) interconnects multiple trip units to provide total coordination for short-time protection.

Instantaneous protection protects the installation against phase-to-phase, phase- to-neutral and phase-to-ground short circuits.

The protection operates with a definite time characteristic.

It trips without additional time delay when the setting current Ii is exceeded. The protection offers two selectable tripping times:

• Standard tripping time: 50 ms for applications requiring selectivity. Selectivity requires correctly sizing another circuit breaker installed downstream of the MasterPacT circuit breaker.

• Fast tripping time: 30 ms (used when selectivity is not required).

Ground-fault protection can be achieved in two ways:

• By performing the summation of the three phases and neutral currents.

• By means of an external sensor (Source Ground Protection [SGR]For SGR option please consult Schneider Electric.*) installed around the cable connecting the transformer neutral point to ground. The SGR sensor is connected to the MicroLogic 6.0 X control unit through an MDGF interface module.

Replacement Parts and Accessories for MicroLogic X Control Units
				Catalog Number
MicroLogic X Embedded Display (EHMI)		MicroLogic X embedded display & wireless card		LV850054SP
MicroLogic XI Embedded Display (EHMI)		MicroLogic X embedded display & wireless card		LV850054WWSP
MicroLogic X Battery + Transparent Cover		Battery (1 part)		LV833593SP
		Transparent Cover (1 part) For MicroLogic X		LV850053SP
Transparent Cover with access to holes (1 part) for MicroLogic X		Transparent Cover with access to holes (1 part) for MicroLogic X		LV839453SP
Voltage Power Supply Module (VPS)		Voltage power supply module (VPS) for MicroLogic X		LV850060SP
Microswitches for MTZ1		Microswitches for MTZ circuit breakers		LV847906SP
USB Cable (miniUSB/USB) for MicroLogic X				LV850067SP
Mobile Power Pack for MicroLogic X (by APC)				LV850055SP
ZSI Interface module (restraint interface module)	120 Vac			LV848892SP
USB Cable for MicroLogic X Control Unit		USB Cable (miniUSB/USB) for MicroLogic X control unit / 1 part	Sensor Rating 400/1600 A	LV850067SP

Replacement Parts and Accessories for MicroLogic X Control Units
				Catalog Number

External Sensors		External Sensor for Ground-Fault Protection (TCE)	Sensor rating 400/2000 A Sensor rating 1000/4000 A Sensor rating 4000/6300 A (MTZ3)	LV834035SP LV834036SP LV848182SP
			Single sensor kit 2000/6300 A	LV848904SP
			3 layer bus 2000 A	LV848905SP
		Source Ground Return (SGR) Ground-Fault Protection	External Sensor (SGR)	LV833579SP
			MDGF Summing Module	LV848891SP
		Voltage Measurement Input (for Circuit Breakers Supplied via Bottom Terminals)	Voltage Measurement Input Fixed	LV847506
			Drawout	LV848533

A four-pole circuit breaker neutral protection is set remotely:

• Neutral protection set at unprotected.

• Neutral protection set at 0.5 x Ir.

• Neutral protection set at Ir.
  Neutral protection is greater than Ir, but lower than In and limited at 1.6 Ir phase.

For a three-pole circuit breaker used in a 4-wire circuit, the protection of the neutral requires an additional external neutral CT (ENCT). A long-time overcurrent characteristic is dedicated to the neutral protection.

The MicroLogic X control unit continuously monitors the electrical continuity of the circuit breaker tripping coil. It generates an alarm if a problem is detected.

If the circuit breaker is tripped from an overcurrent event or from one of the protective functions the circuit breaker is locked in the open position until it is reset manually or electrically. MasterPacT MTZ circuit breakers are also equipped with an interlocking function (see MasterPacT MTZ Locking and Interlocking Accessories).

If the circuit breaker trips due to an overcurrent trip event or from a protection setting, the SDE contact will change state and signal the event. The SDE contact will stay closed until the circuit breaker is reset (seeOvercurrent Trip Indication Contacts (SDE) and Remote Reset After Overcurrent Trip ).

The MicroLogic X control unit is equipped with dual protection settings which allow the user to have a second set of protection settings. This allows users to easily switch between settings.

A typical application is to adjust the short-circuit protection when an installation can be supplied by two sources (grid / generator set) with different levels of available short-circuit current. The settings can be selected by one of the following means:

• EcoStruxure Power Device App

• by a digital input through the IO module

• via Ethernet

• from the embedded HMI

Five LEDs are available on the front of the MicroLogic X control unit.

1. The PreWarn/Warn LED is a bicolor LED with two functions:

   1. PreWarn/Warn LED changes to orange when I > 0.9 Ir

   2. Warn LED changes to red when I > 1.05 Ir

2. The Ir LED is dedicated to long time overload protection, it changes to red when the protection trips.

3. The Isd/Ii LED is dedicated to short-time and instantaneous short-circuit protection. It changes to red with a short-time or instantaneous overcurrent event.

4. The Ig/IΔn LED is dedicated to ground-fault protection. It changes to red when that protection trips.

5. The Op. LED is dedicated to the optional protections and changes to red when any of the optional protections trip.

The fault indication LEDs remains ON four hours after trip if not reset by the test/reset pushbutton. After four hours without reset it is possible to reactivate the trip indication LEDs by pushing the test/reset pushbutton.

The battery charge is continuously monitored.

Trip history is captured and stored in the control unit, and can be retrieved and evaluated using Ecoreach™ software and the EcoStruxure Power Device App.

Each trip inside the trip history (except the last one) includes:

• Type of protection that caused the trip: long-time (overload), short-time (short-circuit), instantaneous (short-circuit), ground fault.

• Date and time of the fault.

The last 50 trip histories can also be retrieved by means of a PC running EcoStruxure Power Commission Software.

In addition, MicroLogic X control unit also logs:

• Last electrical values measured before the fault (voltages, currents, frequency, current and voltage unbalance levels),

• Tripping current during the fault just before the MasterPacT MTZ circuit breaker trip (phase, neutral and ground currents).

• Protection settings.

The last trip may be retrieved through the NFC powerless wireless communication while the circuit breaker is open and the MicroLogic X control unit is not energized.

The protection settings can be set by means of the embedded display, a smartphone via Bluetooth technology, or with EcoStruxure Power Commission Software running on a PC.

EcoStruxure Power Commission Software allows:

• Setting and checking the protections.

• Downloading current settings and uploading new settings.

• Checking the circuit breaker operation.

• Retrieving and displaying information processed by the MicroLogic X control unit:

  • Measurements

  • Alarms

  • Warnings

  • Diagnostics

• Generating and storing reports.

Setting changes are recorded in the protection history, including:

• Date and the time of the last setting change.

• Previous settings and new settings.

The NFC wireless connection allows access to the active trip settings while the circuit breakers is Open and the MicroLogic control unit is not energized.

The general configuration menu of the MicroLogic X control unit’s embedded display allows:

• Enabling or disabling the protection setting change from the embedded display.

• Enabling or disabling the protection setting change from external access:

  • Smartphone via Bluetooth technology

  • PC running EcoStruxure Power Commission Software

  • Ethernet and Modbus SL (RTU) communication.

ZSI is a system designed to reduce the stress on electrical distribution equipment during short-circuit or ground-fault conditions. It uses previously-coordinated protection to reduce the fault tripping time while maintaining selectivity. Each version of the MicroLogic X control unit includes the ZSI function. The ZSI function is associated with short-time short-circuit protection and ground-fault protection.

The control unit detecting a fault sends a signal upstream and checks for a signal arriving from downstream. If there is a signal from downstream, the circuit breaker remains closed for the full duration of its tripping delay. If there is no signal from downstream, the circuit breaker opens immediately, regardless of the tripping-delay setting.

Zone selective interlocking can be implemented between all types of MasterPacT MTZ circuit breakers.

When ZSI connects MasterPacT MTZ circuit breakers with circuit breakers other than MasterPacT MTZ, it may be necessary to use a ZSI Interface Module.

Fault 1

Only circuit breaker A detects the fault. Because it receives no signal from downstream, it trips with no intentional delay, regardless of its tripping delay set to 0.3.

Fault 2

Circuit breakers A and B detect the fault. Circuit breaker A receives a restraint signal from B and remains closed for the full duration of its tripping delay set to 0.3. Circuit breaker B does not receive a signal from downstream and opens immediately, in spite of its tripping delay set to 0.2.

Limits to Device Interconnection:

• A maximum of 15 upstreams devices may be connected to the ZSI input (Z1-Z2).

• A maximum of 15 downstream devices may be connected to the ZSI input
  (Z3-Z4). If additional units are needed, a ZSI Interface Module is required.

The ZSI Interface Module in a ZSI system with MasterPacT MTZ circuit breakers equipped with MicroLogic X control units:

• Boosts the voltage level of the restraint signal.

• Converts the restraint signal to be compatible with other types of Schneider Electric™ circuit breakers (MasterPacT NT/NW) and Square D™ circuit breakers.

• Provides double insulation to meet requirements of IEC standards when upstream and downstream are different generations of devices (MasterPacT MTZ, MasterPacT NT/NW).

Within a ZSI system, the voltage level of the restraint signal must be maintained at a certain level in order to activate the time delay of electronic trip devices.

If the restraint signal is too weak to activate the time delay feature, all devices that sense the fault will trip with no intentional delay.

The voltage level of the restraint signal can be ineffective due to:

• Restraint wire length exceeding 300 m (984 ft.).

  If restraint wire length exceeds 300 m (984 ft.), the voltage drop along the control wire will weaken the restraint signal until it can no longer activate the time delay on the upstream device. If wire length exceeds 300 m (984 ft.), a ZSI module must be placed in the circuit to boost the voltage level of the restraint signal.

• One device sending a restraint signal to many devices.

  In addition, if the number of upstream circuit breakers exceeds 15, then a ZSI module is required.

• Varying signal levels from different electronic trip systems.

For further details on allowable ZSI combinations, please refer to the ZSI interface module installation bulletin NHA12883.

Characteristics

• Maximum rated operational voltage (V): 690 Vac, 50/60 Hz.

• Power supply: 24 Vdc +25/-20% , 6 mA.

• Maximum operating temperature surrounding the module when installed inside electrical equipment: -35°C to 75°C (-31°F to 167°F).

• Standards compliance: IEC 60950-1, CISPR 22, CISPR 24, UL 489, UL 489SE.

• CE marked according to LVD (Low Voltage Directive 2014/35/EU) EN 60950-1 and EMC directive (2014/30/EU) EN55022, EN55024.

Connection & Installation

• Terminal strips, jumpers and 35 mm DIN mounting rail (IEC/EN 60715).

• Twisted wire with a braided shield, 300 Vac, 2.5–0.4 mm² (22 AWG).

The instantaneous override and close and latch are fixed trip settings to protect the circuit breaker when there is a high fault condition. These settings are typically higher than the standard instantaneous setting and function without regard to any other protection settings.

Instantaneous override is a fixed trip setting to open the circuit breaker, under 25 ms, in the event of fault which exceeds the instantaneous override trip value.

The close and latch rating is a fixed trip setting set lower than instantaneous override, to protect the circuit breaker in the event of closing the circuit breaker on an existing fault condition. After 20 ms the circuit breakers reverts to the "instantaneous override" setting.