Chint NM1LE-250S/4300S-160A Disjuntor de corrente residual em caixa moldada de 4 pólos

Chint NM1LE-250S/4300S-160A is a 4-pole molded case disjuntor de corrente residual (RCB). It is suitable for power distribution systems with AC 50Hz and rated voltage up to 400V, and is mainly used for overload, short-circuit and residual current protection. The following is a detailed analysis of its key parameters and functions:

1. Core Parameters and Model Meaning
2. Model Structure

NM1LE: Series code, where “NM” stands for molded case circuit breaker, e “LE” indicates the function of residual current protection.

250S: Frame current is 250A; “S” means the breaking capacity is 30kA (em conformidade com GB/T 14048.2 padrão).

4300S:

4: 4-projeto de poste, which can disconnect three-phase live wires and neutral wire simultaneously.

300: The release type is thermal-magnetic (dual release), which has both overload long-time delay and short-circuit instantaneous protection functions.

S: May indicate the breaking capacity level (consistent with the “S” after the frame current).

160UM: Rated current is 160A, applicable to circuits where the load current does not exceed this value.

2. Residual Current Protection Characteristics

Rated residual operating current (IΔn): 100-200-300mA with three adjustable gears. The sensitivity can be selected according to actual needs (por exemplo, 300mA is suitable for fire protection, and 100mA is suitable for personal safety protection).

Residual breaking time: ≤0.1 second (non-delayed type), which can quickly cut off the residual current circuit to ensure safety.

Residual non-operating current (IΔno): 50% of IΔn (ou seja, 50-100-150mA), so as to avoid false tripping.

3. Breakig Capacity and Short-Circuit Protection

Rated ultimate short-circuit breaking capacity (UTI): 30o, which can reliably break when the short-circuit current reaches 30kA, so as to protect lines and equipment.

Arc flash distance: ≤50mm, which reduces the hazard of electric arc during short-circuit.

1. Funções e cenários de aplicativos
2. Multiple Protection Functions

Proteção contra sobrecarga: The thermal release is used to monitor the current. When the load current exceeds the rated value, the circuit will be disconnected with a delay according to the inverse time characteristic.

Proteção contra curto-circuito: The magnetic release is triggered instantly when short-circuit current occurs, and quickly cuts off the circuit to prevent equipment damage.

Residual current protection: It monitors the residual current in real time. When the residual current reaches the set value, it trips immediately to prevent electric shock and electrical fire.

2. Application Scope

Industrial power distribution: Used as the main switch or branch switch of the distribution cabinet, it is suitable for scenarios such as motor control and equipment power supply.

Commercial and civil use: Can be used in distribution boxes of office buildings and residences to protect the safety of end circuits, and is especially suitable for humid environments (such as kitchens and bathrooms).

Special environments: Supports operation in a wide temperature range from -5℃ to +40℃, and can withstand environments with an altitude below 2000 meters and pollution degree 3.

III. Installation and Operation Characteristics

1. Métodos de instalação

Fixed installation: Fixed in the distribution cabinet through front-panel wiring, suportando instalação vertical ou horizontal.

Accessory expansion: Accessories such as alarm contacts, shunt releases, and undervoltage releases can be added to realize remote control or fault early warning (por exemplo, the shunt release can open the circuit through an external signal).

2. Operation and Maintenance

Manual operation: Direct switching on/off through the handle, with intuitive and safe operation.

Tool-free maintenance: The modular design facilitates maintenance, and the standard phase isolation plates prevent phase-to-phase short circuits.

Service life parameters: Mechanical life is 20,000 vezes, and electrical life is 8,000 vezes, which reduces the replacement frequency.

1. Certificação e Conformidade

Standard certification: Has passed certifications such as CCC, ENVIAR, and CE, complies with international standards including GB/T 14048.2 e CEI 60947-2, and features reliable quality.

Environmental adaptability: IP20 protection rating, which is dust-proof and anti-electric shock, and adaptable to dusty or humid environments.

1. Precautions for Model Selection
2. Correspondência de carga: Ensure that the rated current of 160A matches the actual load current to avoid overload or underload operation.
3. Residual current sensitivity: Select the residual operating current according to the scenario (por exemplo, 30mA for direct contact protection, 300mA for fire protection).
4. Accessory requirements: If remote control or fault alarm is needed, configure corresponding accessories in advance (por exemplo, additional model selection is required for shunt releases).
5. Price reference: The market price is approximately 242-468 RMB por unidade, and the specific price is subject to the quotation of distributors.
6. Typical Application Example

In a three-phase four-wire industrial power distribution system, NM1LE-250S/4300S-160A can be used as a branch switch to protect a motor with a rated power of approximately 75kW. By setting the residual operating current to 300mA, it can effectively prevent residual current fires caused by motor insulation aging; at the same time, the thermal-magnetic release can cope with the instantaneous inrush current when the motor starts, ensuring the safe operation of the equipment.