Power Connections NIII_Z_1: Check Connection System - 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.

DANGER
HAZARD OF DEVICE FALLING Be sure that lifting equipment has lifting capacity for the device being lifted. Follow manufacturer’s instructions for use of lifting equipment. Wear hard hat, safety shoes, and heavy gloves. Failure to follow these instructions will result in death or serious injury.

Procedure Definition

Procedure characteristics	Description
Action	Check that the connection terminals and cables and/or busbars are correctly tightened. Check presence and state of grease. Check penetration of terminals in clusters in the case of a drawout device. Clean contact surfaces.
Goal	Verify normal temperature rise on device and customer connections according to IEC standards.
Frequency	Refer to Recommended Frequency for the Intermediate End-User Maintenance Program.
Special indications	–
Necessary tools	White abrasive pad (for example, Scotch-Brite) Torque wrench Small paintbrush New bolts, nuts, and washers
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 - Connectors - Instruction Sheet MasterPacT MTZ2/MTZ3 - Connectors - 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	–	–	N/A
Drawout	–	–	Removed from chassis

Example of Hardware Connection

A Terminal screw factory-tightened to 13 N•m (MasterPacT MTZ1) and 17 N•m (MasterPacT MTZ2/MTZ3)

B Circuit breaker terminal

C Busbar

D Bolt

E Washer

F Nut

Fixed Device: Checking Mounting of Connection Terminals to Device and Cables And/Or Busbars to Connection Terminals

Step	Action	Corrective action
1	Disconnect busbars from all the connection terminals. Connection types: Mixed connection Vertical rear connection Horizontal rear connection	Advise customer in case of damage to busbars noticed during disconnection.
2	Check the recommended torque value on the device: For MasterPacT MTZ1: 13 N•m For MasterPacT MTZ2/MTZ3: 17 N•m
3	Make sure that the screws are not overtightened: Set the torque wrench to 1 N•m under the recommended value, and then tighten connection terminals to this value. Set the torque wrench to the recommended value, and then tighten connection terminals to this value.	If a screw cannot be tightened to this value, contact your Schneider Electric Services representative.
4	Clean the busbar contact surfaces and customer terminals by using a white abrasive pad.	If there is a major change in color, contact your Schneider Electric Services representative.
5	Disconnect cables from all the connection terminals.	Advise customer in case of damage to cables noticed during disconnection.
6	Clean the contact surfaces of the cable lugs by using a white abrasive pad.	Advise customer in case of damage to the cable insulation (for example, cracks or cable shrinkage).
7	Reconnect the cables and/or busbars with a new set of bolts, nuts, and washers, and then tighten to the recommended torque. NOTE: Standard connection hardware is class 8.8 steel hardware with contact washers. For MTZ2 40, MTZ3 40, MTZ3 50, and MTZ3 63, it is recommended to use A80 stainless steel hardware.

Drawout Device: Checking Mounting of Connection Terminals to Device and Cables And/Or Busbars to Connection Terminals

Step	Action	Corrective action
1	Check the recommended torque value on the device: For MasterPacT MTZ1: 13 N•m For MasterPacT MTZ2/MTZ3: 17 N•m
2	Make sure that the screws are not overtightened: Set the torque wrench to 1 N•m under the recommended value, and then tighten connection terminals to this value. Set the torque wrench to the recommended value, and then tighten connection terminals to this value.	If a screw cannot be tightened to this value, contact your Schneider Electric Services representative.
3	Check the state of the grease on internal terminals on device.	If there is excessive grease, spread the grease uniformly across the zone with a small paintbrush. If there is no grease or there is a change in color or texture of grease, contact your Schneider Electric Services representative.
4	Check that the depth of the penetration of internal terminals in the clusters, indicated by the mark, is about 5 mm.	If penetration depth is less that 5 mm, contact your Schneider Electric Services representative.
5	Open manually the top and bottom safety shutters, and check presence of grease on the clusters.	If there is excessive grease, spread the grease uniformly across the zone with a small paintbrush. If there is no grease or there is a change in color or texture of grease, contact your Schneider Electric Services representative.
6	Disconnect customer cables and/or busbars from all the connection terminals on the chassis.	Advise customer in case of damage to cables or busbars noticed during disconnection.
7	Make sure that the screws are not overtightened: Set the torque wrench to 1 N•m under the recommended value, and then tighten connection terminals to this value.	If a screw cannot be tightened to this value, contact your Schneider Electric Services representative.
8	Without removing the customer terminals, tighten connection terminals to the recommended value: For MasterPacT MTZ1: 13 N•m For MasterPacT MTZ2/MTZ3: 17 N•m	If a screw cannot be tightened to this value, contact your Schneider Electric Services representative.
9	Clean the busbar contact surfaces and customer terminals by using a white abrasive pad.	If there is a major change in color, contact your Schneider Electric Services representative.
10	Clean the contact surfaces of the cable lugs by using a white abrasive pad.
11	Reconnect the cables and/or busbars with a new set of bolts, nuts, and washers, and then tighten to the recommended torque. NOTE: Standard connection hardware is class 8.8 steel hardware with contact washers. For MTZ2 40, MTZ3 40, MTZ3 50, and MTZ3 63, it is recommended to use A80 stainless steel hardware.

Terminal Mounting on Device and Recommended Tightening Torque

Refer to the following documentation:

MasterPacT MTZ1 - Connectors - Instruction Sheet
MasterPacT MTZ2/MTZ3 - Connectors - Instruction Sheet

Recommended Tightening Torque of Connecting Busbars

The following table shows the tightening torques to be used for connecting busbars (Cu ETP - French standard NFA 51-100) to the circuit breaker. These values are for use with copper busbars and steel nuts and bolts, class 8.8. The same torques can be used with AGS-T52 quality aluminum bars (French standard NFA 02-104 or American National Standard H-35-1).

Ø (mm) Nominal	Ø (mm) Drilling	Tightening torques (N•m) with grower or flat washers	Tightening torques (N•m) with contact or corrugated washers
10	11	37.5	50

Ø (mm)

Nominal

Ø (mm)

Drilling

Tightening torques (N•m) with grower or flat washers

Tightening torques (N•m) with contact or corrugated washers

10

11

37.5

50