Maintenance
9.2 Corrective Maintenance
WOGeneric TEAAC / 2008
Siemens AG Operating Instructions 1.03 1RQ671...-Z 57
Tightening torques
The bolted connections with metal contact surfaces (end shields, bearing cartridge parts,
terminal box parts bolted onto the stator frame) should be tightened to the following torques,
depending on the thread size.
Table 9-2 Tightening torques for bolted connections with a tolerance of ±10%.
Case M4 M5 M6 M8 M10 M12 M16 M20 M24
A 1.2 2.5 4 8 13 20 40 - - Nm
B 1.3 2.6 4.5 10 20 34 83 160 280 Nm
C 3 5 8 20 40 70 170 340 600 Nm
The tightening torques in the different rows apply to the following cases:
● Case A
Applies to electrical connections in which the permissible torque is normally limited by the
bolt materials and/or the current carrying capacity of the insulators, with the exception of
the busbar connections in case B.
● Case B
Applies to bolts made from lower-strength components (e.g., aluminum) or of property
class 8.8 (acc. to ISO 898-1).
● Case C
Applies to bolts of property class 8.8 or A4-70 (acc. to ISO 898-1), but only in connections
made from higher-strength components (e.g., gray cast iron, steel or cast steel).
Please refer to the relevant sections and drawings for all other tightening torques (electrical
connections and bolted connections for parts with flat gaskets). [ID 78.01]