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Embed fabricated ‘C’ channels in the foundation and place the MCC on these channels. The base frame of the MCC should be tackwelded to these channels.
Ensure that the MCC is mounted on a flat and levelled surface. Use shims if the floor is uneven foundation may cause misalignment of sections, busbars and hinged doors of the unit.
Locate and level the first sections in position on the foundation channels.
Place second section next to the first section.
Remove top plates above the horizontal busbars of both these sections. Remove fishplates from the horizontal busbars and the earthbar.
Clean the fishplates with a wire brush, wipe them with a soft, dry cloth and then immediately apply contact grease on them. Hindustan Petroleum MPL (EXXON)/Petroleum Jelly J.P. grade contact grease is recommended.
Bolt adjacent sections together before joining the busbars.
Join horizontal busbars and earthbar of the two sections with fishplates prepared as per (6) above. Use hardware supplied with the MCC. In case of one bar per phase, the fishplates should be fitted on the same side of the bar had there been two bars per phase.
Tighten all electrical
connections with a torque wrench to the torque
values given below:
| Size od bolt |
Torque in m. kg |
| M8 |
0.85 |
| M10 |
1.88 |
| M12 |
3.20 |
| M16 |
7.30 |
Replace top plates.
Join auxiliary busboys located in the front, using fishplates provided with the board.
Connect interpanel wires to the adjacent transport unit terminals.
Check alignment of all
feeder doors.
Take care of the following :
In case MCC is located in dusty surroundings, ensure that all doors are closed firmly to prevent ingress of such dust.
If plant atmosphere is likely to contain excessive percentage of steam or reactive gases comprising sulphur or chlorine, ensure that MCC is placed in a separate pressurised room.
Oblong holes are provided for fishplate joints. Extra drilling on the busbars/fish plates should be avoided because it will create a bad joint.
While making joints/connections, ensure that sleeve/tape is removed at the location of the joint between the two conductors/flats.
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