JR28 Series Contact Relay
Model: JR28 Series
Protection Type: Thermal Overload Relay
Phase: 3-Phase
Rated Insulation Voltage (Ui): 690V AC
Rated Operational Voltage (Ue): 380V/660V AC 50/60Hz
Adjustable Current Range: 0.1A – 93A (Multiple Specifications Available)
Trip Class: 10A
Contact Capacity: 1NO + 1NC
Action Mode: Manual Reset / Automatic Reset
Mounting: 35mm Standard DIN Rail Mounting
Protection Degree: IP20
Standards: IEC 60947, CE, RoHS Certified
Mechanical Life: ≥ 100,000 Operations
Electrical Life: ≥ 10,000 Operations
The JR28 Thermal Relay is a high-performance electromechanical protection device designed for three-phase AC motors. Engineered to detect overload, phase failure, and current imbalance, it acts as a critical safety barrier to prevent motor burnout in industrial applications. Compatible with most AC contactors, the JR28 combines precise adjustment, robust construction, and easy installation—making it the go-to choice for global industrial automation, manufacturing.
Key Features
Detects overload, phase loss, and current imbalance (≤10%) to safeguard motors from damage.
Wide adjustable current range (0.1A – 630A, customizable) with clear calibration scales for accurate setting.
High-temperature resistant shell (PC flame-retardant material) and silver alloy contacts for long service life (≥10,000 operations).
Din-rail or panel mounting options; perfectly matched with CJX2, CJX4, and other standard AC contactors.
Supports manual and automatic reset (selectable) for flexible operation in different industrial scenarios.
Technical Specifications
| Parameter | Details |
|---|---|
| Rated Voltage | AC 380V/660V, 50/60Hz |
| Rated Current | 0.1A – 93A (multiple models available) |
| Protection Functions | Overload, phase failure, current imbalance |
| Reset Type | Manual / Automatic |
| Contact Configuration | 1 NO + 1 NC (standard), 2 NO + 2 NC (optional) |
| Insulation Resistance | ≥100MΩ (500V DC) |
| Dielectric Strength | 2kV AC, 1min |
| Operating Temperature | -25℃ to +60℃ |
| Mounting Method | Din-rail (35mm) / Panel Mount |
Application Scenarios
- Manufacturing: Conveyor belts, pumps, fans, and compressors
- HVAC Systems: Air conditioning units, ventilation fans, and water chillers
- Construction Machinery: Small electric motors in hoists and mixers
- Agricultural Equipment: Irrigation pumps and grain processing machinery
- Commercial Facilities: Elevators, escalators, and water supply systems
Installation & Wiring Guide
- Mounting: Fix the relay to a 35mm Din-rail or panel using the included mounting bracket.
- Wiring: Connect the motor’s three-phase power lines to the relay’s input terminals; link the output terminals to the contactor’s auxiliary circuit.
- Setting: Adjust the current dial to match the motor’s rated current (recommended: 1.05× motor rated current).
- Testing: After installation, simulate an overload condition to verify the relay trips correctly.
FAQ
Q1: What is the difference between manual and automatic reset?
Q2: Can the JR28 be used with single-phase motors?
Q3: What is the lead time for bulk orders?
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