Use Of Aluminum Conductors; Using Single-Stranded Cables; Internal Equipotential Bonding - Siemens SIMOTICS FD 1LL1 Operating Instructions Manual

6.5.6

Use of 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
● Then grease the contact areas immediately using neutral Vaseline. This prevents a new
For 1XB7.. terminal boxes with aluminum connection bars, you can also connect copper cables
using copper cable lugs.
6.5.7

Using single-stranded cables

NOTICE
High temperatures from induced eddy currents
With high currents and where several single-stranded cables are used instead of multiple-
stranded cables, high temperatures can result in the cable entry area due to induced eddy
currents. This can result in material damage or even a machine failure.
● After commissioning, ensure that the temperature limits of the connected power cables are
● Use a cable entry plate made of non-ferrous metal.
6.5.8

Internal equipotential bonding

Between the ground terminal in the terminal box enclosure and the machine enclosure, the
fixing screws of the terminal box serve as PE conductor connection.
SIMOTICS FD 1LL1
Operating Instructions 01/2019
contact areas on the conductor and/or the mating piece. Do this using a brush or file.
oxide layer from forming.
NOTICE
Aluminum flow due to contact pressure
Aluminum flows 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 fire 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 24 hours and then again after
approximately four weeks. Make sure that the terminals are de-energized before you
tighten the nuts.
not exceeded during operation. This temperature effect can be reduced by altering the
conditions at the entry points or by using modified cable entry plates after consultation with
the manufacturing plant.
Electrical connection
6.5 Inserting and routing the cables
85