Siemens SIMOTICS XP 1MB155, Руководство по эксплуатации, Страница: 79 / 152

Electrical connection
6.6 Conductor connection
1MB155 / 1MB555
Operating Instructions, 03/2018, A5E41926185A
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6.6.1 Cable ends with wire end sleeves
1. Preferably use end sleeves instead of soldering cable ends.
2. Before connecting, attach the end sleeves so as to form a technically correct, current-
carrying crimped joint at the end of the conductor.
WARNING
Risk of explosion due to excessive temperature rise
If the end of the conductor is not correctly enclosed by the end sleeve, 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 end sleeve. Attach the end sleeve correctly.
6.6.2 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 file.
● Then grease the contact areas immediately using neutral Vaseline. This prevents a new
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.