Use Of Aluminum Conductors - Siemens 1LA8 Operating & Installation Instructions Manual

Lug terminal connections may be installed if ordered accordingly, which are suitable for
connecting flexible and stranded conductors without the use of wire end ferrules. If you wish
to use wire end ferrules, then before connecting the cable, attach these so as to form an
appropriate, current-carrying crimped joint at the end of the conductor.
Danger of explosion if the conductor ends become too hot
If the end of the conductor is not correctly enclosed by the wire end ferrule, but is trapped by
it, this can lead to overheating. The temperature class of the machine can be exceeded. This
can trigger ignition of an explosive mixture. This can result in death, serious injury or material
damage.
● Insert only one conductor end into each wire end ferrule. Attach the wire end ferrule
● Insert only one conductor end into each terminal.
6.4.7

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
SIMOTICS TN Series N-compact 1LA8
Operating Instructions 08/2017
WARNING
correctly.
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.
Electrical connection
6.4 Introducing and routing the cables
81