Siemens 3RU21160KC0 Thermal Overload Relay
Trade-off considerations for SIRIUS 3RU2116 overload relay
- Thermal operating principle vs electronic protection — no trip current adjustment; calibrated for a fixed 0.9–1.25 A window, which suits straightforward motor protection but may require a different relay for variable load profiles.
- Box encapsulation vs open-frame design — environmental protection is inherent, yet visual inspection of contact wear is limited without disassembly.
- S00 size matching Siemens contactors — ensures mechanical fit and coordinated protection, though this ties the relay to a specific form factor and supplier ecosystem.
- ROHS3 Compliant status — confirms environmental compliance, but does not indicate overload class (Class 10, 20, etc.) which affects tripping behavior under locked-rotor conditions.
- Active product status — confirmed in catalog, though current stock is zero, so lead time and minimum order quantities remain field-verification items.
Parametric comparison with SIRIUS 3RU2116 alternates
The seed and three catalog alternates are compared below; application suitability requires independent qualification.
| MPN | Current Range (A) | Similarity |
|---|---|---|
| 3RU21160KC0 (seed) | 0.9–1.25 | — |
| 3RU21160KJ0 | 0.9–1.25 | 0.9282 |
| 3RU21160EC0 | 0.28–0.4 | 0.9282 |
| 3RU21160HC0 | 0.55–0.8 | 0.9282 |
- 3RU21160KJ0: same current range (0.9–1.25 A), same SIRIUS 3RU2116 base; differs only in trailing variant code, likely a packing or certification suffix.
- 3RU21160EC0: same thermal relay type and contactor compatibility; current range shifts to 0.28–0.4 A, placing it in a lower-power segment of the same series.
- 3RU21160HC0: same family and box enclosure; current range 0.55–0.8 A, providing mid-range coverage within the 3RU2116 line.