Accessories

Spring-Charging Motor (NW)

Spring-Charging Motor (NT)

The spring-charging motor automatically charges the spring mechanism for closing the circuit breaker and also recharges the spring mechanism when the circuit breaker is in the ON position. Instantaneous reclosing of the circuit breaker is thus possible following circuit breaker opening. The spring-mechanism charging handle is used only as a backup if auxiliary power is absent.

The spring-charging motor is equipped as standard with a limit switch contact (CH) that signals the charged position of the mechanism (springs charged).

The inrush currents for these devices are approximately 200 VA. When low supply voltages (12, 24 or 48 V) are used, the maximum allowable wire length is dependent on the voltage and the wire size.

Shunt Trip (MX1) and Shunt Close (XF)

Shunt Trip (MX1): When energized, the shunt trip instantaneously opens the circuit breaker. The shunt trip may be energized continuously or intermittently.

Shunt Close (XF): Remotely closes the circuit breaker if the spring mechanism is charged.

Communication versions of the MX1 and XF are available for direct connection via the circuit breaker communication module (BCM ULP).

Second Shunt Trip (MX2)

This function opens the circuit breaker via an electrical order.

It is made up of:

• Shunt trip (MX2, second MX) or,

• Undervoltage trip (MN)

  • Instantaneous trip

  • Fixed undervoltage trip (time delayed) or,

  • Adjustable undervoltage trip (time delayed)

As shown in the wiring diagram for the remote tripping function below, the delay unit (installed outside the circuit breaker) may be disabled by an emergency off button to obtain non-delayed opening of the circuit breaker.

When energized, the shunt trip (MX1 or MX2) instantaneously opens the circuit breaker.

The undervoltage trip (MN) instantaneously opens the circuit breaker when its supply voltage drops to a value between 35% and 70% of its rated voltage.

If the undervoltage trip is not energized, it is impossible to close the circuit breaker, either manually or electrically. An attempt to close the circuit breaker produces no movement of the main contacts. Closing is allowed when the supply voltage of the undervoltage trip reaches 85% of rated voltage.

Wire Diagram for the Remote Tripping Function

Time-Delay Module for Undervoltage Trip (MN)

To eliminate circuit breaker nuisance tripping during temporary voltage dips (micro-breaks), operation of the undervoltage trip (MN) can be delayed. This function is achieved by adding an external delay unit (either adjustable or non-adjustable) to the undervoltage trip (MN) circuit.

Ready-to-Close
Switch (PF)

The ready-to-close position switch indicates that the following conditions are met and the circuit breaker can be closed:

• The circuit breaker is open.

• The closing springs are charged.

• There is no standing closing or opening order.

Located on the front panel of the circuit breaker, this push button carries out electrical closing of the circuit breaker, taking into account all of the safety functions that are part of the control/monitoring system of the installation. The push button is installed on the control circuit of the shunt close, and connects to the communicating shunt close module (XF-COM). Terminal A2 of XF-COM is used to remotely close the circuit breaker.

Electrical Closing Push Button (BPFE)

• Remote reset (RES): following tripping, the remote reset (RES) resets the overcurrent trip switch (SDE) and the mechanical indicator. (Voltage rating: 110/130 Vac and 200/240 Vac.) RES is not compatible with an additional overcurrent trip switch (SDE2).

• Automatic reset after fault-trip: Following tripping, a reset of the mechanical indicator (reset button) is no longer required to enable circuit breaker closing (factory adjustable only).

Auxiliary Switch (OF) with Four Contacts for MasterPact NW Circuit Breaker

MasterPact NT Aux Switch (OF) with One Contact

The rotary-type auxiliary switches are directly driven by the trip mechanism when the minimum isolation distance between the main circuit breaker contact is reached.

Overcurrent Trip Switch (SDE)

Circuit breaker tripping due to a fault is signalled by a red mechanical fault indicator (reset) and one overcurrent trip switch (SDE).

Following tripping, the mechanical indicator must be reset before the circuit breaker may be closed. An additional overcurrent trip switch (SDE2) is supplied as an option and is not compatible with the remote reset (RES).

Connected/Closed Switch (EF)—NW only

This switch combines the “device connected” and “device closed” information to produce “circuit closed” information. The connected/closed switch (EF) is supplied as an option and must be used with an additional auxiliary switch (OF) and fits into its connector (it is not available for ring terminals).

Cradle Position Switch (CE, CD, CT)

Three series of optional auxiliary switches are available for the cradle:

• Cradle position switches to indicate the connected position (CE).

• Cradle position switches to indicate the disconnected position (CD). This position is indicated when the required clearance for isolation of the power and auxiliary circuits is reached.

• Cradle position switches to indicate the test position (CT). In this position, the power circuits are disconnected and the auxiliary circuits are connected.

Additional Actuators for Cradle Position Switches on MasterPact NW Circuit Breakers

A set of additional actuators may be installed on the cradle to change or add the functions of the cradle position switches. Each standard actuator can be replaced by any other actuator to change the function of the cradle position switch.

Cradle Position Switch Actuators
Actuator for up to Three CE Switches (standard)	Actuator for up to Three CD Switches (standard)	Actuator for up to Three CT Switches (standard)

External Neutral Current Transformer (CT)

The sensor is installed on the neutral conductor for neutral protection and metering and residual current ground-fault protection for equipment.

For SGR System: The sensor is installed around the connection of the transformer neutral point to ground and connects to the MicroLogic 6.0A, 6.0P or 6.0H trip units. SGR requires a modified differential ground-fault (MDGF) sensor and MDGF interface module to connect to the trip unit.

For MDGF System: The MDGF sensor is installed on each phase and neutral of each circuit breaker and connects to the MicroLogic trip unit through an MDGF module. See MDGF instruction bulletin 48049-182.

Voltage Measurement Inputs

Voltage measurement inputs are required for power measurements. As standard, the trip unit is supplied by internal voltage measurement inputs placed on the bottom terminals of the circuit breaker. On request, the internal voltage measurement inputs may be replaced by an external source.

Sensor Plug

Sensor plugs (standard) are used to set the sensor rating (I_n) of the circuit breaker, are field replaceable and are offered at 50–100% of frame rating.

Adjustable Rating Plug

Eight interchangeable rating plugs are available to limit the long-time threshold setting range for greater versatility.

External Power Supply Module

Power supply modules are available in six input voltages: 24/30 Vdc, 48/60 Vdc, 125 Vdc, 110/130 Vac, 200/240 Vac, and 380/415 Vac (all +10%, -15%). The output voltage for each is 24 Vdc; the output power is 5 VA/5 W (ripple < 5%). The modules are not UL^® Listed.

When used with the MicroLogic A, P, and H trip units, a power supply module makes it possible to:

• Display currents less than 20% of sensor (I_n).

• Maintain display of tripping causes after opening of the circuit breaker (P and H trip units only).

• Store the value of the interrupted current (P and H trip units only).

• Power the M2C module (P and H trip units only).

External Battery Backup Module

The external battery backup module provides up to 12 hours of backup power for the power supply module.

M6C Programmable Contact Module

M2C Programmable Contact Module

These contacts are used with the MicroLogic P and H trip units, and indicate the type of fault and instantaneous or delayed threshold overruns (i.e trip unit protection pick-up, current/voltage unbalance, under/over voltage, reverse power, phase rotation, under/over frequency, and load shedding). The M2C unit is powered from the trip unit’s 24 Vdc source (100 mA consumption); the M6C unit requires an external 24 Vdc power supply (100 mA consumption).

They are programmed via the trip unit using a keypad or via a supervisory station with the COM communication option. They may be programmed:

• with instantaneous return to the initial state,

• without return to the initial state,

• with return to the initial state following a delay.

Zone-selective interlocking (ZSI) is used to reduce the stress on electrical distribution equipment during fault conditions by reducing the time it takes to clear the fault, while maintaining system coordination between overcurrent protective devices.

During a short-circuit or ground-fault condition on a ZSI system, the device directly ahead of the fault sends a signal upstream via control wiring to restrain upstream circuit breakers from tripping and then trips with no intentional time delay to clear the fault. Upstream devices which receive a restraint signal obey their short-time and/or ground-fault delay settings to maintain coordination in other areas of the system. Upstream devices that do not receive a restraint signal trip with no intentional time delay.

For ZSI to work, trip settings must be coordinated so a downstream circuit breaker will trip before an upstream circuit breaker under overload, short-circuit or ground-fault conditions. (Effective coordination requires a system coordination study.)

Example of Zone-Selective Interlocking

Fault 1—The upstream circuit breaker (A) will clear the fault with no intentional delay, regardless of its time-delay setting.

Fault 2—Circuit breaker (B) will inform upstream circuit breaker (A) that it is clearing the fault. This will prevent circuit breaker (A) from tripping instantaneously. Circuit breaker (A) will trip at the end of its time delay setting if the fault is not cleared during this time.

Restraint Interface Module (RIM)

The restraint interface module (RIM) is used to allow zone-selective interlocking communications between circuit breakers with old MicroLogic, Merlin Gerin™, or Federal Pioneer™ trip units and GC series ground-fault relays.

Downstream circuit breakers with MicroLogic 2.0A, 5.0A, 5.0P, 5.0H, 6.0A, 6.0P, and 6.0H trip units can restrain up to 15 upstream circuit breakers with MicroLogic 5.0A, 5.0P, 5.0H, 6.0A, 6.0P and 6.0H trip units without requiring a restraint interface module. If the number of upstream circuit breakers exceeds 15, then a RIM is required.

Hand-Held Test Kit

The hand held test kit may be used to:

• Verify trip unit operation, the mechanical operation of the circuit breaker, and the electrical continuity of the connection between the trip solenoid and the trip unit.

• Supply control power to the trip unit for settings via the keypad when the circuit breaker is open (MicroLogic type A, P or H trip units).

• Inhibit thermal imaging for primary injection test (MicroLogic type A, P or H trip units).

• Inhibit ground fault for primary injection test (MicroLogic type A, P or H trip units).

• Self-restrain zone-selective interlocking (ZSI).

Full-Function Test Kit

The full-function test kit can be used to verify

LSIG functionality.

• Optional

• Can be used to check trip unit operation, for example:

  • Display of settings.

  • Operating tests on the electronic component.

  • Automatic and manual tests on protection functions (trip curve verification).

  • Tests on the zone-selective interlocking (ZSI) functions.

  • Inhibit thermal imaging for primary injection testing.

  • Self-restrain zone-selective interlocking (ZSI).

• Can also be used to:

  • Check mechanical operation of the circuit breaker.

  • Check the electrical continuity of connection between the trip solenoid and the trip unit.

  • Print the trip unit and circuit breaker test report when used in conjunction with a PC. FFTK report generator software (cat. no. FFTKRPT-V1-0) is required.

Push Button Lock

A transparent cover blocks access to the push buttons used to open and close the device. It is possible to independently lock the opening button and/or the closing button. The push buttons may be locked using:

• One to three padlocks: 3/16–5/16 in. diameter, not supplied.

• A wire seal.

• Two screws.

Open Position Key Lock (NW)

Open Position Padlock Provision (NW)

The circuit breaker is locked in the off position by physically keeping the opening push button pressed down using one of the following:

• One to three padlocks: 3/16–5/16 in. diameter, not supplied.

• Key locks: One or two Ronis, Castell, or Profalux key locks are available. (MasterPact NT circuit breakers may have only one key lock on the circuit breaker.)

Keys may be removed only when locking is effective. The key locks are available in any of the following configurations:

• One key lock.

• One key lock mounted on the device plus one identical key lock supplied separately for interlocking with another device.

• Two different key locks mounted on the circuit breaker for double locking.

A locking kit for installation of one or two key locks may be ordered separately.

Disconnected Position Locking Provisions

The circuit breaker can be locked in the disconnected position by key interlock (optional) or padlock (standard). The key interlock is on the cradle and accessible with the door locked.

• Key interlock, Ronis, Castell, or Profalux key locks are available. Key is captive when key interlock is unlocked.

• Locking on disconnected, test, and connected positions is optional.

Door Interlock (NW)

The door interlock prevents the compartment door from being opened when the circuit breaker is in the connected or test position. If the circuit breaker is put into the connected position with the door open, the door can be closed without disconnecting the circuit breaker. For greater protection, this interlock can be used in conjunction with the open door racking interlock.

The racking interlock is optional. It prevents insertion of the racking crank unless the OFF push button is pressed. Not available for MasterPact NT circuit breakers.

Open Door Racking Interlock (NW)

The racking interlock prevents racking in the circuit breaker when the door is open. (Insertion of the circuit breaker racking crank is not possible when the compartment door is open.

The optional cable door interlock prevents the compartment door from being opened when the circuit breaker is in the closed position. This kit includes:

Cable Door Interlock Kit Contents

Source changeover interlocks allow mechanical interlocking between two or three circuit breakers (fixed and drawout).

Interlocking Two Circuit Breakers

• Interlocking Two Mains Using Rods

• Interlocking Two Mains Using Cables

Interlocking Three Circuit Breakers Using Cables

• Interlocking Two Mains and One Generator

• Interlocking Two Mains and One Tie

• Interlocking Three Mains

Source Changeover Interlocks
Two NW Circuit Breakers Interlocked Using Rods		Three NW Circuit Breakers Interlocked Using Cables

The cradle rejection feature (standard) ensures that only the properly designated circuit breaker or switch is matched with the selected cradle assembly.

Cradle Rejection Kit Contents (NW)

Cradle Rejection Kit Contents (NT)

Automatic Spring Discharge Mechanism (NW)

The automatic spring discharge mechanism is optional. It releases the closing spring energy when the circuit breaker is moved from the disconnected position to the fully withdrawn position. Not available for MasterPact NT circuit breakers.

Rail padlocking is standard for cradles. When used in combination with the disconnected position locking device, rail padlocking prevents the movement of the circuit breaker from the disconnected position to the fully withdrawn position when the padlock hasp is pulled out and locked.

Mechanical Operation Counter (CDM)

The mechanical operation counter (CDM) registers the total number of operating cycles. One CDM is installed per circuit breaker.

The shutters automatically block access to the main disconnects when the circuit breaker is in the disconnected, test, or fully withdrawn position. The shutter lock is used to prevent connection of the circuit breaker or to lock the shutters in the closed position.

Not available on cradles with ArcBlok™ technology.

These door escutcheons provide a frame and seal for the circuit breaker.

Door Escutcheon (NW Fixed)

Door Escutcheon (NW Drawout)

Transparent Cover (CCP)

The cover is hinged-mounted and locked with a milled head, and is designed to be installed on the door escutcheon.