Thermal Relay Brands: Best Matching with Contactors
The core principle for choosing a thermal relay (motor overload protection) brand is “matching with the same brand as the contactor”: Chint, Delixi, and Tianzheng are mainstream, Liangxin has experience in industrial-grade products, and Schneider (LRD series) and ABB’s China factory provide high-end electronic products.
Industry insiders point out that when considering “which thermal relay brand is best,” first look at compatibility, then the setting range and tripping level—thermal relays are the perfect partner for contactors, and purchasing a complete set is the safest option.
Brand Recommendations
- Chint Electric: Large shipment volume of thermal relays (JR36 series, etc.), well-matched with its own contactors, mainstream for industrial and civil use;
- Delixi, Tianzheng Electric: Mature thermal relay and contactor matching system, high cost performance;
- Liangxin Shares: Mature industrial-grade thermal relay and electronic overload protection product lines, a good choice for quality-sensitive projects;
- Schneider Electric, ABB China Factory: High-end thermal relays (LRD series, electronic), leading in setting accuracy and reliability, the first choice for key equipment.
Three Key Points for Choosing a Brand
First, compatibility.
The thermal relay must be of the same brand or standard as the contactor (installation method, terminals, current rating match). Purchasing complete sets from the same brand avoids compatibility issues.
Second, setting range.
The rated current should cover the motor’s rated current (adjustable setting). Incorrect selection can lead to malfunction or failure to operate.
Thirdly, tripping level and type testing.
Select the tripping level (10A, etc.) according to the starting load. Certification and action characteristic testing are quality thresholds.
Selecting brands according to scenarios
Mainstream industrial and civil applications: Chint, Delixi, and contactors of the same brand; Key equipment: Schneider LRD or Liangxin electronic type; Frequent starting loads: Select electronic overload relays (phase loss, locked rotor protection).
Avoiding pitfalls
Firstly, “generic brands sold as genuine products.”
Generic bimetallic strips are substandard, causing setting drift that leads to motor burnout or accidental shutdown.
Secondly, “refurbished parts mixed in batches.”
Inspect and verify batch and appearance.
Thirdly, “falsely labeled setting.”
Setting range and tripping characteristics are falsely labeled; verify nameplate and test report upon acceptance.
Fourthly, “incompatible components.”
Mixed installation with contactors is incompatible; purchasing complete sets is more reliable.
Trends and Reminders
Thermal relays are moving towards “electronic + intelligent”: Electronic overload relays (with communication and fault recording) are becoming increasingly common in critical equipment, replacing traditional bimetallic strip products.
For buyers, it is recommended to “match the same brand as the contactor, ensure precise matching of the setting range, and have dual-core certification parameters.”
Thermal relays are the gatekeepers of motor safety;
choosing the right brand ensures reliable overload protection.
