The core differences between CKJ series and traditional electromagnetic contactors

2025-07-09 13:56:53

The selection of contactors with a voltage level of 1140V needs to be comprehensively considered based on application scenarios, load characteristics, and environmental conditions, while the CKJ series, as the mainstream vacuum contactor for mining and industrial scenarios, has essential differences from traditional electromagnetic contactors. The following is a systematic analysis of the differences between the core elements of selection and key technologies:

1、 Five key elements for selecting 1140V contactors

1. Matching rated current with load type

-Current level: CKJ series covers 63A~630A (such as CKJ5-160A, CKJ5-400A), and should be selected according to 1.2~1.5 times the load 

current. For example, for a 250kW motor (1140V) with a rated current of about 152A, CKJ5-250A (250A) should be selected.

-Load nature:

-AC-3 load (motor start stop): Select models with a power life of ≥ 600000 times (such as the AC3 life of CKJ5-250);

-AC-4 load (inching/reverse braking): requires an electrical lifespan of ≥ 60000 times and enhanced arc extinguishing capability.

2. Control voltage and operational reliability

-Coil voltage: AC 36V/110V/220V/380V can be selected, and wide voltage adaptation is required underground in coal mines (suction voltage 75%~110% Us, release voltage 10%~65% Us).

-Action characteristics: Apply voltage of 85%~110% Us in a normal environment to avoid low voltage refusal.

3. Environmental adaptability design

4. Mechanical and electrical lifespan

-Mechanical lifespan: CKJ5 series reaches 3 million cycles (traditional electromagnetic contactors only have 1 million cycles);

-Electric lifespan: AC3 load is 600000 times (AC4 load is 60000 times), much higher than the traditional contactor's 100000 times (AC3).

5. Security authentication and special functions

-Compulsory certification: GB 3836 explosion-proof certification is required for mining, and GB14048.4 standard is required for industry;

-Function extension:

-Equipped with resistance capacitance absorption box (to suppress operating overvoltage);

-Combine with JDB protector to form an explosion-proof starter.

2、 CKJ series vs traditional electromagnetic contactor: analysis of core differences

?  Arc extinguishing principle and safety

?  Performance and reliability comparison

3、 minrong CKJ series selection typical scenario scheme

1. Explosion proof system in coal mine underground

-Model: CKJ5-250/1140V+JDB protector

-Configuration:

-Coil voltage AC 36V (safe voltage);   

-Double grounding contact anti misoperation;   

-Mechanical lock buckle anti vibration release.   

2. Chemical high-frequency start stop motor

-Model: CKJ5-400/1140V

-Enhanced design:

-Stainless steel shell is corrosion-resistant;   

-Integrated RC absorption box (suppresses VFTO overvoltage).   

3. High voltage distribution of new energy

-Model: CKJ20-1000/1140 (630A~1000A)

-Features:

-Short term tolerance of 4500A (3 times);   

-Support GPRS remote monitoring.   

4、 Selection and Avoidance Guide

1. Lack of vacuum degree detection

-The new installation needs to be tested using the power frequency withstand voltage method (≥ 8kV/3 times without flashover), otherwise it may cause overvoltage interruption and damage to the motor.   

2. Install tilt over limit

-Tilting greater than 15 ° can cause uneven stress on the vacuum tube and shorten its lifespan (standard requirement ≤ 15 °).   

3. Misjudgment of environmental adaptability

-Silicone rubber sealing type should be selected for high humidity environments (such as coastal areas), as ordinary ceramic seals are prone to condensation and flashover.   

Conclusion: The three major scenarios of CKJ series are preferred

1. Frequent operation of medium and high voltage (such as rolling mills/mine hoists) → Utilize their high electrical life (AC3 600000 times);   

2. Explosion proof/high pollution environment (chemical plants/coal mines) → relying on zero arc and IP54 protection;   

3. Energy saving and silent requirements (building air conditioning/hospital) → Maintain power consumption ≤ 40VA and low noise.   

>Selection mnemonic: voltage and current benchmark, choose vacuum in harsh environments;   

>Mining explosion-proof CKJ5, with dual breakthroughs in lifespan and energy efficiency.