Auxiliaries NIII_Z_4: Check Closing and Opening Operations with MN Undervoltage Release

Safety Instructions

DANGER
HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, CSA Z462, NOM 029-STPS, or local equivalent. This equipment must only be installed and serviced by qualified electrical personnel. Unless specified otherwise in the maintenance procedures, all operations (inspection, test, and preventive maintenance) must be carried out with the device, the chassis, and the auxiliary circuits de-energized. Check that the device and the chassis are de-energized on the upstream and downstream terminals. Always use a properly rated voltage sensing device to confirm that the device, the chassis, and the auxiliary circuits are de-energized. Install safety barriers and display a danger sign. During the tests, it is strictly forbidden for anyone to touch the device, the chassis, or the conductors while voltage is applied. Before turning on power to this equipment, check that all connections are made with the correct tightening torque and the device is open (OFF position). Before turning on power to this equipment, put all devices, doors, and covers back in place. Before turning on power to this equipment, beware of potential hazards and carefully inspect the work area for tools and objects that may have been left inside the equipment. Failure to follow these instructions will result in death or serious injury.

DANGER

HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH

Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. See NFPA 70E, CSA Z462, NOM 029-STPS, or local equivalent.
This equipment must only be installed and serviced by qualified electrical personnel.
Unless specified otherwise in the maintenance procedures, all operations (inspection, test, and preventive maintenance) must be carried out with the device, the chassis, and the auxiliary circuits de-energized.
Check that the device and the chassis are de-energized on the upstream and downstream terminals.
Always use a properly rated voltage sensing device to confirm that the device, the chassis, and the auxiliary circuits are de-energized.
Install safety barriers and display a danger sign.
During the tests, it is strictly forbidden for anyone to touch the device, the chassis, or the conductors while voltage is applied.
Before turning on power to this equipment, check that all connections are made with the correct tightening torque and the device is open (OFF position).
Before turning on power to this equipment, put all devices, doors, and covers back in place.
Before turning on power to this equipment, beware of potential hazards and carefully inspect the work area for tools and objects that may have been left inside the equipment.

Failure to follow these instructions will result in death or serious injury.

Procedure Definition

Procedure characteristics	Description
Action	Check closing the device with the MN undervoltage release at Un. Check opening the device with the MN undervoltage release below 0.7 Un. Check closing the device with the MN undervoltage release above 0.35 Un.
Goal	Verify device operation when equipped with an MN undervoltage release operating.
Frequency	Refer to Recommended Frequency for the Intermediate End-User Maintenance Program.
Special indications	Connect the MN undervoltage release to an external power supply. With an MNR delayed undervoltage release, disconnect the MN delay unit.
Necessary tools	Adjustable external power supply Voltmeter External switch
Related documents	MasterPacT MTZ1 - IEC Switch-Disconnectors and Circuit Breakers with MicroLogic X Control Unit - User Guide MasterPacT MTZ2/MTZ3 - IEC Switch-Disconnectors and Circuit Breakers with MicroLogic X Control Unit - User Guide MasterPacT MTZ1/MTZ2/MTZ3 - MN-MX-XF Voltage Releases - Instruction Sheet MasterPacT MTZ1/MTZ2/MTZ3 - MN-MX-XF Communicating Voltage Releases with Diagnostic Function - Instruction Sheet

Preliminary Conditions

The device must comply with the conditions specified below. Refer to the MasterPacT MTZ User Guides to find instructions for operating the device.

Device installation type	Position of poles	Mechanism	Device position in the chassis
Fixed	Open	Charged	N/A
Drawout	Open	Charged	Test

MN Undervoltage Release Wiring Diagram

MN Undervoltage Release Operating Mode

MasterPacT MTZ device status with an MN undervoltage release during voltage drop:
MasterPacT MTZ device status with an MN undervoltage release during voltage increase:

Closing and Opening Procedures with the MN Undervoltage Release

DANGER
HAZARD OF ELECTRIC SHOCK When using the adjustable external power supply, take all suitable measures to protect against electric shock. Failure to follow these instructions will result in death or serious injury.

Before starting this check, it is advisable to execute a few electrical opening and closing cycles as per procedure Mechanism NII_Z_1.

Step	Action	Corrective action
1	Disconnect supply wires on the customer terminal block.
2	Connect the external switch and the adjustable external power supply according to the wiring diagram above.
3	Set the external power supply voltage to Un.
4	Close the external switch.
5	Press the closing pushbutton. The device closes.	If the device does not close: Check that the power supply voltage is set to Un and do the procedure again. If the device still does not close, replace the MN undervoltage release (refer to MasterPacT MTZ - MN-MX-XF Voltage Releases - Instruction Sheet). If the problem persists, contact your Schneider Electric Services representative.
6	Gradually decrease the voltage: The device can open at any voltage between 0.7 Un and 0.35 Un. The device must open at 0.35 Un. The device must remain open below 0.35 Un.	If the device opens before the voltage reaches 0.7 Un, replace the MN undervoltage release. If the device does not open below 0.35 Un, replace the MN undervoltage release. If the device does not remain open below 0.35 Un, replace the MN undervoltage release. Refer to MasterPacT MTZ - MN-MX-XF Voltage Releases - Instruction Sheet to replace the MN undervoltage release. If the problem persists, contact your Schneider Electric Services representative.
7	Set the voltage to a value lower than 0.35 Un.
8	Charge the mechanism.
9	Press the closing pushbutton. The device must not close.	If the device closes: Check that the power supply voltage is set to a value lower than 0.35 Un and do the procedure again. If the device still closes, replace the MN undervoltage release (refer to MasterPacT MTZ - MN-MX-XF Voltage Releases - Instruction Sheet). If the problem persists, contact your Schneider Electric Services representative.
10	Gradually increase the voltage. While pressing the closing pushbutton: The device can close at any voltage between 0.35 Un and 0.85 Un. The device must close at 0.85 Un. The device must remain closed above 0.85 Un.	If the device does not close at 0.85 Un, replace the MN undervoltage release (refer to MasterPacT MTZ - MN-MX-XF Voltage Releases - Instruction Sheet). If the device does not remain closed above 0.85 Un, replace the MN undervoltage release (refer to MasterPacT MTZ - MN-MX-XF Voltage Releases - Instruction Sheet). If the problem persists, contact your Schneider Electric Services representative.
11	Reconnect the customer terminal block according to the initial wiring.
12	Check that the device electrically closes and opens according to procedure Mechanism NII_Z_1.