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U V W
L1 L2 L3
CW
U V W
L1 L2 L3
CCW
Figure 4-1. Phase sequence (IEC).
In
Figure 4-1.:
•
CW=clockwise.
•
CCW=counter clockwise (facing generator drive end).
The neutral terminal is marked with the letter
N
.
4.3.3 Earth connection
The ground cable can be connected inside of the main terminal box.
4.3.4 Insulation distances of main power connections
The connections of the main power cables are designed to withstand demanding
operation conditions where the insulators can be subjected to dirt, humidity and
surge voltages. In order to ensure lasting and trouble free running, it is therefore
important that local requirements or other applicable standards for the insulation
distances are met.
If no local requirements or other applicable standards are available, it is suggested
that the minimum insulation distances mentioned in
Table 4-1. Recommended
minimum insulation distances
are used.
These distances apply both for insulation distances between two different phases,
and for insulation distances between one phase and the earth. The air insulation
distance is the shortest distance through air between two points with different
electrical potential. The surface insulation distance is the shortest distance along
surfaces next to each other between two points with different electrical potential.
Table 4-1. Recommended minimum insulation distances.
Recommended minimum insulation distances: U
≤≤≤≤
690 V
Air insulation distance/[mm]:
6
Surface insulation distance for even surface/[mm]:
10
Surface insulation distance for finned surface/[mm]:
8
4.3.5 Connection of auxiliaries and instruments
Connect the instruments and auxiliary equipment according to the connection
diagram in
Annex 3. Main Connection Drawing
and
Annex 10. Option
Connection Drawing.
