Schneider Electric LRN359N 48-65A Thermal Overload Relay

Schneider LRN359N 48-65A thermal overload relay features a complete certification system that meets full requirements of safety, environmental protection and performance. It is a reliable choice for industrial motor protection, applicable to various global industrial scenarios, especially for overload and phase loss protection of 22-37kW three-phase asynchronous motors.

Official Model Code Explanation

LRN359N 48-65A

LRN: Product family code of Schneider Easy TeSys Protect series thermal overload relays. Different from LRE (electronic type), LRD (standard thermal type) and LRR (TVR series), it is specially designed for motor overload and phase loss protection.
3: Size specification code, representing Size 3 (matching LC1N series contactors), suitable for motors with large rated current.
59: Adjustable current range code. 59 corresponds to 48-65A adjustable range; larger figure means wider current range.
N: Series characteristic code, standing for EasyPact TVS series. It can be directly mounted on EasyPact TVS contactors to realize integrated control.
48-65A: Adjustable setting current range for precise adjustment to match motors of different power ratings.
Core Technical Parameters (Official Standard)

Parameter Category	Specifications	Remarks
Basic Parameters
Protection Type	Thermal overload + Phase loss protection	Compliant with IEC 60947-4-1, providing comprehensive motor protection
Setting Current Range	48-65A	Adjustable design, fits 22-37kW (400V) three-phase asynchronous motors
Trip Class	Class 10A	Trips within 5-10 seconds at 1.2 times rated current, ideal for general industrial motors
Operating Voltage	Max. 690V AC, 50/60Hz	Compatible with various industrial power supply systems and global grid standards
Auxiliary Contacts	1 NO + 1 NC	Standard configuration for control circuits and alarm systems
Performance Parameters
Phase Loss Sensitivity	Trips when one phase is 30%In and the other two are full In	Quickly detect phase loss faults to avoid motor damage
Temperature Compensation	-20℃ ~ +60℃	Maintain stable protection accuracy amid ambient temperature fluctuations
Reset Mode	Manual push-button reset	Manual reset required after fault elimination to avoid misoperation
Contact Rating	5A/400V AC, 3A/250V DC	Satisfy demands of conventional control and alarm circuits
Physical Parameters
Housing Material	High-strength engineering plastic	V0 flame retardant grade, complying with UL 94, high safety
Installation Method	Direct mounting on EasyPact TVS contactors	Modular design, space-saving and easy installation
Protection Degree	IP20	Prevent finger contact with live parts, suitable for cabinet installation
Dimension	W70 × H105 × D75mm	Standard Size 3, fits standard control cabinet layout
Weight	Approx. 0.45kg	Lightweight to reduce load on mounting brackets
Mechanical Life	10,000 trip & reset cycles	High reliability for long-term continuous operation
Electrical Life	100,000 operations	Durable contacts to lower maintenance frequency

Application Guidelines

Recommended Applications (✅ Applicable)

Industrial Motor Protection: Overload, phase loss and locked-rotor protection for three-phase asynchronous motors, especially 22-37kW (400V) motors
Water Pump & Fan Systems: Motor protection for HVAC systems, industrial water pumps and cooling tower fans against overload damage
Compressor & Refrigeration Equipment: Motor protection for air compressors and refrigeration units adapting to frequent start-stop conditions
Conveying Machinery: Protection for belt conveyors, chain conveyors and screw conveyors under fluctuating loads
Building Equipment: Motor protection for elevators and cranes to ensure safe operation
Machine Tool & Automation: Motor protection for CNC machining centers and production line equipment to improve system stability

Unrecommended Scenarios (❌ Avoid)

Single-phase motor protection: LRN series is designed exclusively for three-phase motors; use dedicated protectors for single-phase motors
High-frequency start/stop applications (over 10 times per minute): Frequent overloads shorten service life; electronic protectors are preferred
Ambient temperature above 60℃ or below -20℃: Beyond temperature compensation range leads to reduced protection accuracy
Corrosive gas environments (chlorine, hydrogen sulfide etc.): Corrodes housing and internal components; anti-corrosion models recommended
Dust-intensive environments without shielding: Dust impairs heat dissipation and mechanical movement; dust covers are required
Severe vibration environments (over 3Gn): Loosens internal parts and affects protection performance; anti-vibration products suggested
Cross-Brand Equivalent Replacement List

Original Model	Alternative Brand	Replacement Model	Compatibility Notes
Schneider LRN359N 48-65A	ABB	TA25DU63	Same 48-65A range, Class 10A, direct mounting type for ABB contactors
	Siemens	3RU6146-4CB0	45-63A range, Class 10A, 1NO+1NC auxiliary contacts, compatible mounting size
	Omron	TH-N120KP	48-65A range, Class 10A, phase loss protection, matches Omron contactors
	Chint	NR2-63/Z	48-65A range, Class 10A, cost-effective domestic alternative
	Delixi	JR36-63	45-63A range, Class 10A, economical match for Delixi contactors

Complete LRN Series Order Codes (Latest Official Version)

Order No.	Full Model	Setting Current Range	Matched Motor Power (400V)	Applicable Contactor
LRN359N	LRN359N 48-65A	48-65A	22-37kW	LC1N11500~LC1N15000
LRN01N	LRN01N 0.1-0.16A	0.1-0.16A	0.04-0.075kW	LC1N0601~LC1N0901
LRN02N	LRN02N 0.16-0.25A	0.16-0.25A	0.075-0.11kW	LC1N0601~LC1N0901
LRN03N	LRN03N 0.25-0.4A	0.25-0.4A	0.11-0.18kW	LC1N0601~LC1N0901
LRN04N	LRN04N 0.4-0.63A	0.4-0.63A	0.18-0.37kW	LC1N0601~LC1N1201
LRN05N	LRN05N 0.63-1A	0.63-1A	0.37-0.55kW	LC1N0901~LC1N1201
LRN06N	LRN06N 1-1.6A	1-1.6A	0.55-0.75kW	LC1N1201~LC1N1801
LRN07N	LRN07N 1.6-2.5A	1.6-2.5A	0.75-1.5kW	LC1N1801~LC1N2501
LRN08N	LRN08N 2.5-4A	2.5-4A	1.5-2.2kW	LC1N2501~LC1N3201
LRN10N	LRN10N 4-6A	4-6A	2.2-3kW	LC1N3201~LC1N4001
LRN12N	LRN12N 5.5-8A	5.5-8A	3-4kW	LC1N4001~LC1N5001
LRN14N	LRN14N 7-10A	7-10A	4-5.5kW	LC1N5001~LC1N6501
LRN16N	LRN16N 9-13A	9-13A	5.5-7.5kW	LC1N6501~LC1N8001
LRN22N	LRN22N 16-24A	16-24A	7.5-15kW	LC1N8001~LC1N11500
LRN322N	LRN322N 17-25A	17-25A	11-15kW	LC1N11500~LC1N15000
LRN353N	LRN353N 23-32A	23-32A	15-18.5kW	LC1N15000~LC1N18500
LRN355N	LRN355N 32-45A	32-45A	18.5-22kW	LC1N18500~LC1N22500
LRN357N	LRN357N 37-50A	37-50A	22-30kW	LC1N22500~LC1N30000
LRN361N	LRN361N 55-70A	55-70A	30-37kW	LC1N30000~LC1N37000
LRN363N	LRN363N 63-80A	63-80A	37-45kW	LC1N37000~LC1N45000
LRN365N	LRN365N 80-104A	80-104A	45-55kW	LC1N45000~LC1N55000

Common Fault Diagnosis & Maintenance Solutions (Official Recommended)

Fault Phenomenon	Possible Causes	Troubleshooting Steps	Maintenance Solutions
Frequent False Tripping	1. Too low setting current	1. Check if setting current matches motor rated current	1. Adjust setting current to 1.0~1.1 times motor rated current
	2. Motor overloaded	2. Measure operating current against rated value	2. Reduce load overload ratio
	3. Excessively high ambient temperature	3. Confirm ambient temperature below 60℃	3. Improve ventilation and lower ambient temperature
	4. Unbalanced three-phase current	4. Ensure three-phase current unbalance less than 5%	4. Inspect motors and wiring to eliminate unbalance
No Tripping under Overload	1. Too high setting current	1. Check if setting current exceeds 1.1 times motor rated current	1. Lower setting current properly
	2. Damaged thermal elements	2. Inspect deformed or burnt thermal elements	2. Replace identical thermal elements
	3. Mechanical jamming	3. Manually test trip mechanism flexibility	3. Clean and lubricate trip mechanism
	4. Failed phase loss protection	4. Simulate phase loss to verify protection function	4. Check phase loss circuit or replace relay if needed
Difficult Reset	1. Uncooled thermal elements	1. Wait sufficient cooling time (about 5 minutes)	1. Extend cooling time or adopt forced cooling
	2. Stuck reset mechanism	2. Check jammed reset button	2. Clean foreign matters inside reset structure
	3. Fatigued internal springs	3. Inspect deformed internal springs	3. Replace damaged spring assemblies
Inactive Auxiliary Contacts	1. Oxidized or ablated contacts	1. Check oxide layer or ablation on contact surface	1. Clean contacts or replace contact components if severely damaged
	2. Failed contact springs	2. Verify elasticity of contact springs	2. Replace invalid springs
	3. Malfunctioned mechanical linkage	3. Test flexibility of linkage structure	3. Adjust linkage structure for accurate action
Loose Installation	1. Unfastened mounting screws	1. Tighten all mounting screws	1. Retighten fixing screws
	2. Poor matching between contactor and relay	2. Check fitting clearance between contactor and relay	2. Adjust mounting position for perfect fitting
	3. Excessive vibration	3. Confirm ambient vibration below 3Gn	3. Install vibration dampers to reduce vibration impact

Typical Application Cases

Case 1 Sewage Treatment Plant: Water Pump Motor Protection System

Project Background

A large municipal sewage treatment plant is equipped with 20 sets of 37kW submersible sewage pumps. A stable motor protection system is required to prevent overload and phase loss damage.

Core Challenges

Frequent start-stop and fluctuating loads easily cause motor overload
High humidity environment (over 85% RH) demands high-level protection for electrical devices
Unbalanced three-phase current caused by different cable lengths requires reliable phase loss protection
Long-term continuous operation requires high stability of protective devices

Solutions

Match each water pump motor with LRN359N 48-65A thermal overload relay plus LC1N15000 contactor

Set setting current at 55A (rated current of 37kW motor is approx. 53A) for 1.04 times overload protection

Connect auxiliary contacts to PLC system to realize remote monitoring and fault alarming

Install dehumidifiers inside control cabinets to keep ambient humidity below 70%

Application Effects

Motor failure rate dropped from 8% to 1.2%, saving annual maintenance cost about 600,000 RMB
100% accuracy in phase loss fault detection effectively protects motors
2-year trouble-free continuous operation reduces maintenance frequency by 80%
Remote monitoring realizes early fault warning and cuts unplanned downtime by 50%

Case 2 Cement Production Line: Kiln Exhaust Fan Protection System

Project Background

A large cement manufacturer uses 10 sets of 30kW kiln exhaust fans for dust and waste gas emission. Stable motor protection is essential to ensure uninterrupted production.

Core Challenges

Variable fan loads easily lead to overload and locked rotor
High ambient temperature up to 50℃ puts forward high requirements on temperature compensation performance
Heavy dust affects equipment heat dissipation and mechanical operation
24-hour non-stop production requires zero false tripping of protective devices

Solutions

Adopt LRN359N 48-65A thermal overload relay with setting current set at 48A (rated current of 30kW motor is approx. 47A)

Apply Class 10A trip class for quick response to overload faults

Equip dust covers and regularly clean relay surface to guarantee good heat dissipation

Link with PLC system to realize overload early warning and automatic shutdown protection

Application Effects

Improved fan motor stability extends continuous production time from 72 hours to 168 hours
Stable operation at 50℃ ambient temperature with effective temperature compensation
Maintenance cycle prolonged from 1 month to 6 months cutting maintenance cost by 70%
Annual downtime loss reduced by about 1.2 million RMB and production efficiency increased by 15%
Compliance Certification & Air Freight Information
Certifications

CE: Compliant with EU industrial safety standard EN 60947-4-1

UL: Meets safety requirements for North American industrial equipment

RoHS: Lead-free eco-friendly design complying with EU environmental directives

CCC: In line with China Compulsory Certification standards

IEC: Conforms to IEC international standards for global application

Air Freight Compliance

No built-in lithium batteries, supercapacitors or hazardous substances

Classified as ordinary industrial electrical goods with no special transportation documents required for air and sea shipment

Packaged per ISTA 2A standard for direct international delivery

Origin: Manufactured in France or China with unified global Schneider quality standards, available in original imported and domestic assembled versions

Certification Summary of Schneider LRN359N 48-65A Thermal Overload Relay

Conclusion: Schneider LRN359N 48-65A thermal overload relay has obtained complete authoritative domestic and international certifications, fully complying with major global industrial safety standards and applicable to all kinds of industrial motor protection occasions.

Core Certification List (Officially Confirmed)

Certification Type	Certification Name	Standard No.	Compliance Description
International Basic Certifications	CE	EN 60947-4-1	Comply with EU LVD and EMC directives, mandatory access certificate for European market
	IEC	IEC 60947-4-1	Follow IEC industrial electrical safety specifications for global use
	UL	UL 60947-4-1	North American safety approval for USA and Canada markets
	CSA	CSA 60947-4-1	Canadian standard certification covering North America together with UL
China Compulsory Certification	CCC	GB 14048.4	Mandatory China certification complying with domestic low-voltage apparatus standards
Environmental Certifications	RoHS	2011/65/EU	EU hazardous substance restriction directive for eco-friendly application worldwide
	China RoHS	China RoHS Declaration	Accord with Chinese electronic product pollution control regulations
	REACH	REACH Regulation	Free of SVHC high-concern substances per EU chemical management rules
Performance Certifications	Trip Class Certification	Class 10A	Meet IEC 60947-4-1 for standard overload response speed for general industrial motors
	Electrical Safety Certification	GB 14048.4	Satisfy Chinese national standards for reliable insulation and mechanical safety

Core Value & Application Significance of Certifications

Global Market Access: Approved by CE, UL, CSA etc., eligible for direct entry into European, American, Asian and other mainstream industrial markets without extra tests
Safety Guarantee: Conform to IEC 60947-4-1 and GB 14048.4 to ensure reliable protection against motor overload, phase loss and locked rotor and avoid equipment damage & safety accidents
Environmental Compliance: RoHS and REACH certificates confirm no heavy hazardous substances, meeting green production demands and corporate ESG goals
Consistent Quality: Unified global production standards ensure identical certification level and quality control for both French original and domestically assembled products

Certification Inquiry & Verification Methods