There are three way to selection of contactor:

1. Types of applications, there are many application characteristics (utilization categories): such as AC-1, AC-3, AC-4 and other categories.
https://en.wikipedia.org/wiki/Utilization_categories

2. The size of the rating specification: load power, operational voltage and coil voltage.

3. number of poles (normally open and normally closed contact) and also auxiliary contact.

Released for:Schneider Electric Indonesia