Chint CJX2-6511+NR2-93

Technical File of Chint CJX2-6511 + NR2-93

Chint CJX2-6511 + NR2-93 is a standard electromagnetic starter combination, consisting of a CJX2-6511 Contattore CA and an NR2-93 thermal overload relay. It is mainly used for remote control, overload and phase failure protection of AC motors, and is widely applied in industrial automation and electrical control systems.

1. Interpretazione del modello

1. Parametri tecnici fondamentali
2. CJX2-6511 AC Contactor

2. NR2-93 Thermal Overload Relay

III. Caratteristiche funzionali

1. Features of CJX2-6511 Contactor

High-performance Contacts: Silver alloy contacts with excellent conductivity, strong arc erosion resistance and long service life.

Low-noise Design: Optimized electromagnetic system to reduce noise during pull-in and release.

Struttura modulare: Expandable auxiliary contacts for flexible installation.

Sicuro e affidabile: Conforme a GB/T 14048.4 and IEC/EN 60947-4-1 standard, with short-circuit protection coordination capability.

Ampia adattabilità della tensione: Control coil is compatible with multiple voltage levels to meet the requirements of different control circuits.

2. Features of NR2-93 Thermal Overload Relay

Protezione completa: Provides both overload and phase failure protection to prevent motor burnout due to phase loss operation.

Compensazione della temperatura: Maintains stable protection characteristics when ambient temperature changes.

Action Indication: Clear trip status indication for easy fault troubleshooting.

Flexible Reset: Manual/automatic reset selection to adapt to different control requirements.

Montaggio a innesto: Perfectly matched with CJX2 contactor for quick installation and space saving.

3. Advantages of the Combined System

Integrated Control and Protection: The contactor is responsible for circuit on/off and motor starting, while the thermal overload relay provides overload/phase failure protection, forming a complete control and protection unit.

Standardized Design: Complies with international standards and can be seamlessly integrated with other electrical components.

Manutenzione facile: Modular structure allows easy component replacement and reduces maintenance costs.

1. Ambito di applicazione
2. Controllo motorio: Adatto per avviamenti frequenti, fermandosi, forward and reverse rotation control of three-phase AC motors with power below 30kW (380V).
3. Attrezzature industriali: General machinery such as fans, pompe dell'acqua, compressori, conveyors and machine tools.
4. Ingegneria elettrica edile: Central air conditioning systems, fire pumps and elevator control systems.
5. Altre applicazioni: Long-distance controlled power transmission and distribution systems, and electrical circuits requiring overload protection.
6. Raccomandazioni per la selezione
7. Basic Selection Principles

Contactor Selection: The rated current of main contacts shall be ≥ 1.2-1.5 volte la corrente nominale del motore (inductive load).

Thermal Relay Selection: The adjustable current range shall cover the rated current of the motor (usually set to 0.95-1.05 volte la corrente nominale del motore).

Tensione della bobina: Selected according to the power supply of the control circuit, 220V or 380V AC are commonly used.

2. Motor Power Matching Table (380V)

3. Precauzioni per l'installazione e l'uso

Mounting Direction: The contactor and thermal overload relay can be installed horizontally or vertically, with an inclination angle not exceeding 5°.

Specifiche di cablaggio: The terminals of the main circuit shall be tightened to avoid heating; the cross-sectional area of the control circuit wire shall be ≥ 1.5mm².

Requisiti ambientali: Evitare l'installazione in ambienti umidi, ambienti polverosi o con gas corrosivi; altitude ≤ 2000m.

Coordinamento della protezione: Must be used with circuit breakers to provide short-circuit protection.

1. Risoluzione dei problemi

VII. Substitution and Compatibility

VIII. Riepilogo

Chint CJX2-6511 + NR2-93 is a cost-effective and highly reliable motor control and protection solution, especially suitable for frequent starting and protection applications of small and medium-sized motors. Il suo design modulare, standardized interface and comprehensive protection functions make it an ideal choice in the field of industrial automation. Durante la selezione, it is necessary to choose the appropriate adjustable current specification of the thermal overload relay and the coil voltage of the contactor according to the motor power, rated current and control requirements.

Service Life Details of Chint CJX2-6511 + NR2-93

The service life of the Chint CJX2-6511 + NR2-93 combination shall be comprehensively evaluated from three dimensions: vita meccanica (no-load operation times), vita elettrica (on-load operation times) and actual service life, which is also affected by various factors such as operating conditions and maintenance level.

1. Officially Nominal Life Parameters
2. CJX2-6511 AC Contactor

2. NR2-93 Thermal Overload Relay

1. Key Factors Affecting Service Life
2. Factors Affecting Contactor Life

2. Fattore	Influence Mechanism	Influence Degree
   Frequenza operativa	Frequent operation accelerates mechanical wear and contact ablation	Alto (if the frequency is doubled, the life may be halved)
   Tipo di carico	The life of AC-4 load (avviamenti/inversioni frequenti) È 60-80% lower than that of AC-3 load	Alto
   Fluttuazione della tensione	Overvoltage causes coil overheating, and undervoltage causes contact bouncing	Medio-Alto
   Condizioni ambientali	Temperatura > 40℃, umidità, dust and corrosive gas accelerate aging	Medio
   Metodo di montaggio	Non-vertical installation (inclination > 5°) affects heat dissipation and mechanical action	Basso
   Maintenance Level	Regular cleaning and terminal tightening can extend the service life	Medio

   Factors Affecting Thermal Overload Relay Life

III. Life Estimation in Practical Application

1. Calculation of Actual Contactor Life (Esempio)

Assumed working conditions: Categoria di utilizzo AC-3, 100 operations per day, 300 working days per year

Theoretical electrical life: 600,000 operazioni

Annual operation times: 100 operations/day × 300 days = 30,000 operations/year

Expected service life: 600,000 ÷ 30,000 = 20 anni (ideal working conditions)

If it is AC-4 utilization category with 200 operations per day:

Theoretical electrical life: 100,000 operazioni

Annual operation times: 200 × 300 = 60,000 operations/year

Expected service life: 100,000 ÷ 60,000 = about 1.7 anni (severe working conditions)

2. Estimation of Actual Thermal Overload Relay Life

Control Contact Life: Con 50 operations per day, the theoretical 100,000 operations can last for about 5.5 anni.

Heating Element Life: Under normal use (less than 5 overload trips per month), it can work stably for 8-10 anni.

Overall Life: Usually determined by the life of the contactor; the thermal overload relay can be replaced as a wearing part.

1. Practical Suggestions for Extending Service Life
2. Selection Optimization

The rated current of the contactor shall be ≥ 1.2-1.5 volte la corrente nominale del motore.

For frequent starting/reversing conditions, select AC-4 dedicated contactors or use them with derating.

2. Installation and Usage Specifications

Install vertically with good ventilation; control the ambient temperature within -5℃ ~ +40℃.

Keep the control coil voltage stable within ±10% of the rated value.

Set the adjustable current of the thermal overload relay to 0.95-1.05 volte la corrente nominale del motore.

3. Maintenance Measures

Regularly clean the contacts and iron core to remove dust and oil stains.

Check the wiring terminals to prevent loosening and heating.

After 3-5 years of operation of the contactor, the contacts and coil can be replaced.

When the thermal overload relay trips frequently, check the motor load and main circuit.

1. Riepilogo

Under standard working conditions (AC-3, 100 operations per day), the electrical life of the contactor in the Chint CJX2-6511 + NR2-93 combination is about 20 anni, and the mechanical life far exceeds the actual service demand; the overall life of the thermal overload relay is about 10 anni. The actual service life mainly depends on the operating frequency, load type and maintenance level, and may be shortened to 1-2 years under severe working conditions. Through reasonable selection, standardized use and regular maintenance, the service life of the equipment can be effectively extended and the replacement cost can be reduced.