Schneider LR9F7579 | TeSys LRF – electronic thermal overload relay – 300…500 A – class 20

Schneider LR9F7579 | TeSys LRF – Electronic Thermal Overload Relay, 300–500 A, Class 20

The Schneider LR9F7579 is a robust, precision-engineered electronic thermal overload relay from the TeSys LRF series, built for demanding motor protection applications. With a current range of 300–500 A and Class 20 tripping characteristics, this relay is ideal for motors with long acceleration times or high inertia loads.

General Overview:

• Brand: Schneider Electric

• Series: TeSys LRF

• Model: LR9F7579

• Type: Electronic Thermal Overload Relay

• Current Range: 300 to 500 A

• Trip Class: Class 20 (for high-inertia or long-start motors)

Key Features:

• Wide Adjustable Range: 300–500 A, suitable for large motors

• Class 20 Tripping: Allows extended startup duration without nuisance tripping

• Electronic Precision: Offers superior accuracy over traditional thermal relays

• Phase Failure Protection: Detects and reacts to phase imbalance or loss

• Manual/Automatic Reset: User-selectable reset options for flexibility

• Trip Indicator: Clear LED indication for quick diagnostics

• Test Button: Ensures relay functionality during setup or routine checks

• Auxiliary Contacts: 1 NO + 1 NC built-in for status feedback

• Mounting: Direct mount on TeSys F series contactors for easy integration

Technical Specifications:

• Adjustment Range: 300 A to 500 A

• Trip Class: Class 20

• Auxiliary Contacts: 1 normally open + 1 normally closed

• Reset Mode: Manual or automatic

• Mounting Type: Direct mount (compatible with LC1F contactors)

• Operating Temperature: Typically -20°C to +60°C

• Standards: IEC 60947-4-1, IEC 60947-1

• Degree of Protection: IP20 (device body)

Typical Applications:

• High inertia equipment (e.g., crushers, mixers, fans)

• Conveyor systems with long start-up periods

• Heavy industrial motors

• HVAC and pumping systems

• Material processing and transport

Advantages:

• High Accuracy Protection: Reduces motor wear and failure

• Ideal for Tough Loads: Class 20 delay accommodates slow-start motors

• Versatile Integration: Works seamlessly with Schneider TeSys motor starters

• Enhanced Diagnostics: Quick fault identification reduces downtime

• Durable & Compact: Space-saving design with robust components