SIEMENS
SIEMENS 3RU21261FB0 Overload Relay 3.5 A 5 A 690 V AC Trip Class 10
Thermal overload relay with 3.5 A to 5 A range, 690 V AC rating, trip class 10, 1NO/1NC contacts and direct contactor mounting
- Thermal overload protection up to 5 A with adjustable 3.5 A minimum setting
- Trip Class 10 response limits motor damage during sustained overcurrent
- Direct contactor mounting on S0 frame simplifies panel assembly
- Screw terminals provide secure three-phase connections up to 690 V AC
- Auto and manual reset options restore operation after fault clearance
3.5–5 A Thermal Overload Relay
The SIEMENS 3RU21261FB0 is a three-pole thermal overload relay designed for direct mounting on compatible SIRIUS S0 contactors. It protects motors rated between 3.5 A and 5 A in industrial control panels and machinery applications. The unit includes thermal elements and offers both automatic and manual reset modes.
690 V AC Trip Class 10 Limits
Rated for a maximum of 690 V AC, the relay operates within Trip Class 10, meaning it trips within approximately ten seconds at locked-rotor current. The fixed 3.5 A minimum and 5 A maximum settings cannot be adjusted outside this range. Screw terminals accept standard control wiring for the main and auxiliary circuits.
1NO/1NC Auxiliary Contact Decides Fit
A single change-over auxiliary contact provides one normally-open and one normally-closed circuit for signalling or interlocking. If the control scheme requires additional contacts or a different contact arrangement, this relay will not meet the requirement. Verify the contact configuration against the starter wiring diagram before selection.
Highlights
- Thermal overload protection up to 5 A with adjustable 3.5 A minimum setting
- Trip Class 10 response limits motor damage during sustained overcurrent
- Direct contactor mounting on S0 frame simplifies panel assembly
- Screw terminals provide secure three-phase connections up to 690 V AC
- Auto and manual reset options restore operation after fault clearance
Specifications
| Brand | SIEMENS |
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Questions about this item
Should I set the dial at 3.5 A or 5 A for my motor?
Choose a setting between 3.5 A and 5 A that matches your motor's full-load current rating.
What does Trip Class 10 mean for daily operation?
The relay will trip within 10 seconds at 7.2 times the set current, protecting the motor from sustained overloads.
How does the screw-terminal connection affect the 690 V AC rating?
The screw terminals accept solid or stranded conductors rated for the 690 V AC maximum voltage.
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