SIEMENS
SIEMENS 3RU21161HB0 Overload Relay 5.5-8 A 690V AC
Thermal overload relay protects motors from 5.5 to 8 A at 690 V AC with auto or manual reset
- Thermal overload protection for 3-phase motors
- Adjustable trip range from 5.5 to 8 amps
- Rated for 690 V AC maximum voltage
- Trip Class 10 response for standard protection
- Direct contactor mounting with screw terminals
Application fit
The SIEMENS 3RU21161HB0 is a thermal overload relay designed for three-phase motor circuits up to 690V AC. It suits maintenance engineers and panel builders who need adjustable 5.5 to 8 A protection with direct contactor mounting.
Sustained behaviour
Trip Class 10 gives a consistent response under prolonged overcurrent rather than a brief surge. Auto and manual reset modes let the operator choose automatic restart or deliberate intervention after a thermal trip.
Build and connections
Screw terminals accept standard ferrules for secure wiring in vibration-prone cabinets. The S00 frame fits directly onto compatible SIRIUS contactors, reducing DIN-rail space and eliminating separate mounting hardware.
Highlights
- Thermal overload protection for 3-phase motors
- Adjustable trip range from 5.5 to 8 amps
- Rated for 690 V AC maximum voltage
- Trip Class 10 response for standard protection
- Direct contactor mounting with screw terminals
Specifications
| Brand | SIEMENS |
|---|
Questions about this item
How much heat does the 3RU21161HB0 generate when running continuously at 8 A?
The relay uses thermal overload protection rated for 5.5 A to 8 A with Trip Class 10, so sustained current within that range produces only the normal warmth of a bimetallic element.
What contactor frame must I already own to mount this relay directly?
It mounts directly to SIRIUS series contactors in frame size S00 using screw terminals.
Will the 3RU21161HB0 coordinate with an older IEC contactor that uses a different trip class?
The relay is Trip Class 10 and designed for SIRIUS S00 frames; coordination with other trip classes or frames should be verified against the contactor’s time-current curve.
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