6.6.3 Connecting aluminum conductors
If you are using aluminum conductors, then comply with the following:
• Use only cable lugs that are suitable for connecting aluminum conductors.
• Immediately before inserting the aluminum conductor, remove the oxide layer from the 
contact areas on the conductor and/or the mating piece. Do this using a brush or le.
• Then grease the contact areas immediately using neutral Vaseline. This prevents a new oxide 
layer from forming.
NOTICE
Aluminum ow due to contact pressure
Aluminum ows following installation due to the contact pressure. The connection using 
clamping nuts can loosen as a result. The contact resistance increases, obstructing the 
current from being conducted. This can result in re and material damage to the machine 
– or even in total failure, as well as material damage to the plant or system due to machine 
failure.
• Retighten the clamping nuts after approximately 24hours and then again after 
approximately 4 weeks. Make sure that the terminals are de-energized before you 
tighten the nuts.
6.7 Connecting converters
NOTICE
Material damage caused by an excessively high supply voltage
Material damage can occur if the supply voltage is too high for the insulation system.
• Observe the values in the following tables.
SIMOTICS machines can be operated with SINAMICS converters (uncontrolled and controlled 
infeed) when maintaining the permissible voltage peaks.
The insulation system of SIMOTICS machines corresponds to the specications laid down in 
IEC 60034-18-41 according to voltage stress category C (IVIC C = high stress).
Table 6-5 Maximum voltage peaks at the motor terminals for line (DOL) motors, converter operation possible
Rated motor voltage
V
Maximum peak voltage at the motor terminals
Û
phase-to-phase
V
pk
Û
phase-to-ground
V
pk
DC link U
DC
V
≤ 500V 1500 1100 750
Electrical connection
6.7Connecting converters
1LE5, 1PC4 shaft heights 280 ... 355
76 Operating Instructions, 11/2022, A5E41454666A