Cable And Bar Connection; Protective Conductor Connection - ABB MNS R Installation Manual

4.3

Cable and Bar Connection

For any connections and, in particular for those made with standard elements, it is necessary to conform
to the tightening torque indicated by the table in Annexe A.
Circuit breakers and main switching devices are normally connected with cable or busbar. In case of
parallel connection:
1. Power and control cables must be fastened to cable mounting rails.
2. Power and control cables are connected to:
• Terminal boards
• Connection bars or
• Outgoing cable connection unit
The terminations of each circuit breaker installed in the switchboard are silver plated. Before the con-
nection, terminations must be cleaned with a cloth and solvent.
- Check that the connection contact surface is flat and clean.
- Remove burrs, dents and oxidation by means of a file or a rough cloth. In case of busbars with special
protecting treating, after using the above-mentioned tools, restore the protecting treating.
- Remove any grease with a cloth and solvent.
Busbars Connection
Before assembling, carefully clean the busbar contact area with a cloth soaked in solvent, and lightly
grease with vaseline.
- Verify the busbar correct alignment
- Match the coupling elements
- Lock the joints by means of the coupling elements, bolts and nuts on issue.
Busbars, protective and neutral busbars must be screwed up at transportation subdivisions (connecting
elements included). Busbars points of connection are accessible from the rear side. If the installation is
carried out correctly, the holes match. Drilling is not permissible, due to the resulting chips. Contact
surfaces do not need any particular treating. As for tightening torque related to busbar connection, see
Appendix A.
4.3.1

Protective Conductor Connection

All switchboard compartments are normally equipped with an earth busbar as a protection against any
short-circuit current.
The earth busbar is located in the rear side of the switchboard (at the bottom). The earthing busbar joint
of each shipping unit must be made according to the following procedures:
- Remove any traces of oxidation from the contact surfaces of the busbars, by means of a file or emery
cloth.
- Remove any grease with a cloth and solvent.
- Perform the earth busbar joints by means of screws, washers and nuts on issue.
- Cover the joints with grease.
16
1TTS900001M0902