The Siemens SIRIUS 3RT5935-5AM01 is a replacement magnet coil for the size S3 contactor frame, wound for 48 V DC control voltage. It is the service part you order when the original coil on a 3RT1 or 3RT2 contactor in the S3 envelope fails — not a complete contactor, just the electromagnetic actuator that pulls the main and auxiliary contacts in.
Coil voltage and tolerance band
Rated control supply voltage is 48 V DC. The coil holds in across a 0.8 to 1.1 times rated voltage band at 50 Hz — per the datasheet, that means the pickup and seal-in are guaranteed between roughly 38.4 V and 52.8 V. Below the lower threshold the armature may chatter or fail to pull in; above the upper limit you risk overheating the winding over extended duty cycles.
This coil snaps onto the S3 contactor magnet system — the same frame used across the SIRIUS 3RT1 and 3RT2 range for that size class. No DIN-rail mounting on the coil itself; it is a direct mechanical replacement inside the contactor housing. Verify the existing contactor's size marking (S3) before ordering; the S00 and S0 coils share the same voltage options but differ in physical yoke dimensions and cannot interchange.