Mechanism NIII_Z_1: Check the MCH Gear Motor Charging Time at 0.85 Un - MTZ Basic Standard Maintenance Procedures

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 the MCH gear motor charging time at 0.85 Un. Check the continuity of electrical wiring for a drawout device.
Goal	Verify the correct operation of the MCH gear motor.
Frequency	Refer to Recommended Frequency for the Intermediate End-User Maintenance Program.
Special indications	Connect the MCH gear motor to a power supply.
Necessary tools	Adjustable external power supply Voltmeter Stopwatch
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 - MCH Gear Motor - Instruction Sheet MasterPacT MTZ2/MTZ3 - MCH Gear Motor - 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	Discharged	N/A
Drawout	Open	Discharged	Test

MCH Gear Motor Charging Time Definition

The charging time is the time elapsed between the closing order and the moment when the mechanism is fully charged.

The charging time during closing operation and opening/closing operation does not exceed 6 seconds.

Checking the MCH Gear Motor Charging Time During Device Closing

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 verify that the device charges electrically with MCH gear motor as per procedure Mechanism NII_Z_2.

Step	Action	Corrective action
1	Disconnect supply wires B1 and B2 (and B3 if connected) so that the MCH gear motor is not connected to a power supply.
2	Connect terminals B1 and B2 to the adjustable external power supply.
3	Set the voltage to 0.85 Un (minimum Un if the setting is for a range of voltages). The MCH gear motor charges the mechanism. The indicators show that the device is open and the mechanism is charged and ready-to-close.
4	Press the closing pushbutton and start the stopwatch. The device closes and the mechanism is automatically charged.
5	Stop the stopwatch when the mechanism is charged and not ready-to-close. The charging time should be less than 6 seconds.	If the charging time exceeds 6 seconds: Check that the MCH supply voltage remains at 0.85 Un while the MCH gear motor is charging the mechanism. Do the procedure with another external source connected to terminals B1 and B2. If the time is still too long, replace the MCH gear motor. If the problem persists, contact your Schneider Electric Services representative to replace the breaking unit.

Checking the MCH Gear Motor Charging Time During Device Closing/Opening Sequence

Step	Action	Corrective action
1	Open the device.
2	Press the closing pushbutton and immediately the opening pushbutton, and then start the stopwatch.
3	Stop the stopwatch when the indicators show that the device is open and the mechanism is charged and ready-to-close. The charging time should be less than 6 seconds.	If the charging time exceeds 6 seconds: Check that the MCH supply voltage remains at 0.85 Un while the MCH gear motor is charging the mechanism. Do the procedure with another external source connected to terminals B1 and B2. If the time is still too long, replace the MCH gear motor. If the problem persists, contact your Schneider Electric Services representative to replace the breaking unit.

Step

Action

Corrective action

1

Open the device.

2

Press the closing pushbutton and immediately the opening pushbutton, and then start the stopwatch.

3

Stop the stopwatch when the indicators show that the device is open and the mechanism is charged and ready-to-close. The charging time should be less than 6 seconds.

If the charging time exceeds 6 seconds:

Check that the MCH supply voltage remains at 0.85 Un while the MCH gear motor is charging the mechanism.
Do the procedure with another external source connected to terminals B1 and B2.
If the time is still too long, replace the MCH gear motor.

If the problem persists, contact your Schneider Electric Services representative to replace the breaking unit.

Reconnecting the MCH Gear Motor

Step	Action	Corrective action
1	Reconnect the supply wires (B1, B2, and B3 if present) as they were before executing the procedure.
2	Open and close the device to check that the MCH gear motor operates properly.