This part is a kind of semiconductor called 3UA6600-3C.

Function of this product has Overload Relays.

Manufacturers : Siemens

Image and pinout :

Some of the text within the PDF file :

HP Rated Control Overload Relays______ ,!> f- rs Selection > HP Rated starters are priced and istocked less the overload relays. The overload relays can be ordered separately for field installation or they can be factory installed. Factory Installed Overload Relay: A) Select the appropriate overload relay from the chart below. Then add the two digit suffix number (shown bold below) of the overload relay to the starter Catalog Number. See example shown. If the motor FLA is not Overload Relay Setting Ranges In Amperes 0.1-0.16 0.16-0.25 0.25-0.4 0.4-0.63 0.63-1 0.8-1.25 1-1.6 1.25-2 1.6-2.5 2-3.2 2.5-4 3.2-5 4-6.3 2-8 6.3-10 known, refer to Application Data Section for a typical value. B) Add the price of the overload relay to the starter price to obtain the complete list price. Example [ ... ]

3UA6600-3C PDF Datasheet Download