The Siemens 3RH1921-1FE22 is a 4-pole auxiliary switch block designed for side-mounting onto Siemens SIRIUS 3RT10 series contactors (Sizes S00, S0, and select S2/S3 ranges). It provides 2 Normally Open (NO) and 2 Normally Closed (NC) contacts for expanded control circuit feedback, interlocking, and signaling. Rated for up to 690 V AC insulation voltage, this block complies with IEC 60947-5-1 and features a compact 45 mm width with screw terminals and IP20 finger-safe protection. Typical applications include complex motor control panels requiring multiple feedback signals, PLC interlocking circuits, and safety systems where redundant NO/NC contacts are needed.
FAQ
Q: How many contacts does the 3RH1921-1FE22 provide?
A: It provides 4 contacts in total: 2 Normally Open (NO) and 2 Normally Closed (NC), making it a 4-pole auxiliary switch block.
Q: Which Siemens contactors is the 3RH1921-1FE22 compatible with?
A: It is compatible with Siemens 3RT10 SIRIUS contactors in Sizes S00, S0, and select S2/S3 ranges. It snaps onto the side of the contactor.
Q: What is the difference between 3RH1921-1FE22 and 3RH1921-1EA20?
A: The 3RH1921-1EA20 provides 1 NO + 1 NC (2 contacts), while the 3RH1921-1FE22 provides 2 NO + 2 NC (4 contacts) for applications requiring more auxiliary contacts.
Q: What are the current ratings for AC-15 duty?
A: The contacts are rated for 6 A at 400 V AC and 3 A at 690 V AC under AC-15 utilization category per IEC 60947-5-1.
Q: Does the 3RH1921-1FE22 require tools for mounting?
A: No, it features snap-on/clip-on side mounting and does not require screws to attach to the contactor. Only the wire connections require a screwdriver.
Q: What wire sizes can be connected to the screw terminals?
A: The screw terminals with cage clamp accept rigid conductors from 0.75 mm² to 2.5 mm² and flexible conductors with ferrules from 0.75 mm² to 1.5 mm² (20–14 AWG).
Q: Is this auxiliary block suitable for safety circuits?
A: Yes, the contacts comply with IEC 60947-5-1 for mirror contact performance, making them suitable for safety feedback and interlocking applications.
Q: What is the insulation voltage rating of this device?
A: The rated insulation voltage (Ui) is 690 V AC, with a rated impulse withstand voltage of 6 kV.
