Dual-Screen Self-Resetting Overvoltage and Undervoltage Protector

The dual-screen self-resetting overvoltage and undervoltage protector is an electrical protection device developed on the basis of the self-resetting overvoltage and undervoltage protector. It usually has a dual-screen display, which can more intuitively and comprehensively display voltage and other related information. The following is a detailed introduction to it:

Working Principle Chint NXM-1000S/3300-1000A Molded Case Circuit Breaker*

- **Voltage Detection**: It is equipped with a high-precision voltage detection circuit inside, which monitors the voltage status of the power supply line in real time. When it detects that the voltage exceeds the set overvoltage protection value or is lower than the set undervoltage protection value, it will quickly send out a signal.molded case circuit breaker  Price

- **Control and Execution**: The control circuit takes the high-speed micro low-power consumption processor as the core. When it receives the abnormal voltage signal, it will control the action of the magnetic latching relay and other actuators, quickly cut off the circuit, and avoid the abnormal voltage from being sent to the terminal electrical appliances to cause accidents. When the voltage returns to the normal value, the protector will automatically connect the circuit within the specified time to ensure the normal operation of the terminal electrical appliances.Chint NXR series thermal overload relays price

 Functional Features

- **Overvoltage and Undervoltage Protection**: When the line voltage exceeds the set overvoltage value (such as AC270±5V), the protector quickly cuts off the circuit to prevent the electrical equipment from being damaged due to overvoltage; when the line voltage is lower than the set undervoltage value (such as AC170±5V), the protector automatically disconnects the circuit to avoid the performance degradation or damage of the equipment caused by the undervoltage operation.

- **Automatic Recovery**: After the voltage returns to normal, the protector can automatically delay the reset and connect the line without manual operation, ensuring that the equipment can return to normal operation in a short time, and improving the convenience and safety of the equipment.CHINT circuit breaker price*

- **Dual-Screen Display**: It is equipped with two display screens. One can display the real-time voltage value, and the other can display information such as the working status and fault codes, such as overvoltage, undervoltage, delay and other statuses, enabling users to more intuitively and clearly understand the working condition of the protector and the line voltage status, which is convenient for fault troubleshooting and maintenance.CHINT surge protector price

- **Strong Anti-Interference Ability**: When the line has a transient or temporary overvoltage, the protector will not malfunction; for the voltage instability caused by faults such as loose contacts in the line, or sudden power outages and sudden power restores, the protector will not connect the line, which can effectively avoid the damage to the electrical equipment caused by these situations.Schneider Circuit Breakers price

- **Self-Protection Function**: When the line fault voltage is at the highest, the protector itself has good tolerance and will not be damaged, ensuring reliable operation under various harsh voltage conditions.

 Application Scenarios

- **Household Electricity**: It can be installed at the incoming line of the residential distribution box to protect various electrical equipment in the home, such as televisions, computers, refrigerators, washing machines, air conditioners, etc., from the damage of abnormal voltage, extend the service life of the electrical appliances, and ensure the safety of household electricity use.

- **Commercial Places**: In commercial places such as shopping malls, supermarkets, office buildings, hotels, etc., there are a large number of electrical equipment such as lighting equipment, elevators, escalators, refrigerated display cabinets, cash register equipment, computer servers, office appliances, etc. The dual-screen self-resetting overvoltage and undervoltage protector can ensure the normal operation of these equipment under stable voltage, and avoid the damage of the equipment and the interruption of the business caused by the voltage fluctuation.

- **Industrial Field**: Various motors, automated control equipment, PLC (Programmable Logic Controller) systems on the production line of the factory, as well as electric forklifts, cargo elevators, ventilation equipment, etc. in the industrial warehouse all need stable voltage to ensure normal operation. The dual-screen self-resetting overvoltage and undervoltage protector can prevent these equipment from malfunctioning due to overvoltage and undervoltage, reduce the downtime of the production line, improve production efficiency, and ensure the smooth progress of industrial production.

The dual-screen self-resetting overvoltage and undervoltage protector is a high-end electrical device that integrates voltage monitoring, automatic protection and intelligent display. It realizes more intuitive operation status monitoring through the dual-screen interactive design, and is especially suitable for scenarios with high requirements for voltage stability. The following is an explanation from the aspects of technical characteristics, product selection, installation and maintenance, and market dynamics:

 I. Core Technical Characteristics

1. **Dual-Screen Interactive Design**

    - **Main Screen**: It can display the current voltage value (with an accuracy of up to ±1%), current load (supported by some models) and system time in real time, and supports the dynamic refresh of the voltage waveform.

    - **Sub-Screen**: It can display parameters such as the fault type (such as overvoltage, undervoltage, phase loss), action threshold, and delay time, and supports touch or knob adjustment.

    - **Color Warning**: It distinguishes the normal, early warning and fault states through the red/green/yellow three-color backlight, and cooperates with the buzzer to achieve multi-dimensional alarm.

2. **Intelligent Protection Mechanism**

    - **Dynamic Threshold Adjustment**: It supports the custom setting of the overvoltage threshold (170-270V), undervoltage threshold (170-270V) and delay time (1-60 seconds) to meet the voltage tolerance requirements of different equipment.

    - **Anti-Interference Algorithm**: It is equipped with built-in digital filtering technology, which can filter out voltage fluctuations within 500ms to avoid malfunction due to instantaneous interference.

    - **Self-Diagnosis Function**: It regularly detects potential faults such as the wear of the relay contacts and the accuracy deviation of the sensor, and displays the fault code through the sub-screen.

3. **Hardware Upgrade**

    - **Magnetic Latching Relay**: It adopts a bistable design, which only consumes power when the state is switched, with a power consumption of less than 0.5W and a service life of more than 100,000 times.

    - **Wide Voltage Input**: It supports a wide voltage input range of AC100-450V, which is compatible with various power grid standards at home and abroad.

    - **Flame-Retardant Shell**: It is made of V0-level flame-retardant PC material, which can withstand a high temperature of 1000°C, and a surge protection module (optional) is built-in.

II. Product Selection Guide

 (I) Parameter Matching

1. **Rated Current**: Select according to the total power of the load, and the formula is **I = P/(√3×U×cosφ)**. For example, for a 380V three-phase load with a total power of 20kW and cosφ = 0.8, then **I = 20000/(1.732×380×0.8)≈38A** needs to be selected, and it is recommended to select the 63A model.

2. **Voltage Range**: For single-phase in China, select 220V±20% (176-264V), and for three-phase, select 380V±15% (323-437V); for overseas, select according to local standards (such as 110V±10% for the US standard).

3. **Response Time**: It is recommended to select a model with an action time ≤ 0.1 second to protect voltage-sensitive equipment (such as frequency converters, PLCs).

(II) Brand Comparison

 (III) Certification Requirements

- **Domestic**: It needs to pass the CCC certification and comply with the GB/T 14048.11 standard.

- **USA**: It needs to pass the UL 1077 certification and comply with the overcurrent protection requirements of Chapter 240 of the NEC 2023 edition.

- **Europe**: It needs to pass the CE certification and meet the EN 61000-4-11 voltage fluctuation test standard.

III. Installation and Maintenance

1. **Installation Steps**

    - **Location Selection**: Give priority to installing at the incoming line end of the distribution box, with a distance of ≥ 5cm from other equipment to ensure good ventilation.

    - **Wiring Specifications**:

        - Single-phase: L is connected to the live wire, N is connected to the neutral wire, and PE is connected to the ground (yellow-green wire).

        - Three-phase: L1-L3 are connected to the phase wires, N is connected to the neutral wire, and PE is connected to the ground.

        - Use BV wire with a cross-sectional area of more than 2.5mm², and the screw torque needs to reach 2.5N·m.

    - **Debugging and Testing**:

        - Simulate overvoltage (270V) and undervoltage (170V), and check whether the protector acts within 0.1 second.

        - After the voltage recovers, confirm whether the delay time is consistent with the set value (with an error ≤ 5%).

2. **Maintenance Key Points**

    - **Regular Inspection**: Clean the dust on the shell every quarter, and use a multimeter to detect the contact resistance of the contacts (should be < 50mΩ).

    - **Fault Troubleshooting**:

        - Malfunction: Check whether the filter capacitor is aging (test the capacity attenuation with an LCR meter).

        - No display: Measure the voltage at the power input end. If it is abnormal, check whether the front-end air switch has tripped.

    - **Life Management**: Replace the relay contacts when the wear exceeds 0.5mm, and it is recommended to replace the protector as a whole every 5 years.

IV. Market Dynamics and Trends

1. **Technological Innovation**

    - **Internet of Things Integration**: Some new products support 4G/bluetooth communication, and can remotely monitor the voltage curve and set the threshold through the APP, such as the Bull LZGQ-63/1PN model.

    - **Energy Management**: It can be linked with photovoltaic inverters and energy storage systems to achieve intelligent off-peak electricity consumption. For example, the Schneider iCNV series supports the Modbus RTU protocol.

2. **Policy Promotion**

    - The "Residential Design Code" (GB50096-2021) of the Ministry of Housing and Urban-Rural Development of China requires that overvoltage and undervoltage protectors must be installed in newly built residential buildings.

    - The California Energy Commission (CEC) of the United States has incorporated overvoltage and undervoltage protection into the Title 24 energy efficiency standard, requiring all newly built buildings to be compulsorily installed starting from 2025.

3. **Price Trends**

    - Entry-level (single-screen): ¥30-100, suitable for ordinary families.

    - Mid-to-high-end (dual-screen): ¥100-500, integrating functions such as digital display and adjustable parameters.

    - Industrial-grade (three-phase): ¥500-2000, supporting wide voltage and high protection level.

 V. Typical Application Scenarios

1. **Family Scenarios**

    - **Protection Objects**: Air conditioners, refrigerators, smart home appliances (such as robotic vacuum cleaners, projectors).

    - **Case**: A user's smart toilet motherboard was burned out due to the voltage fluctuation of the power grid. After installing the dual-screen protector, no similar problems occurred again.

2. **Commercial Scenarios**

    - **Protection Objects**: POS machines, monitoring systems, LED displays.

    - **Case**: A convenience store's cash register system crashed due to undervoltage. After installing the Delixi DZ47sGQF, the failure rate decreased by 90%.

3. **Industrial Scenarios**

    - **Protection Objects**: PLC control cabinets, servo motors, frequency converters.

    - **Case**: Three frequency converters in a factory were burned out due to a sudden voltage increase. After replacing with the Schneider R9C44263, the annual maintenance cost was reduced by 60%.

VI. Frequently Asked Questions

Q: Does the dual-screen protector need to be grounded?

A: It must be grounded! If it is not grounded, the shell may be charged during a lightning surge, causing a safety accident.

Q: Can it replace the air switch?

A: No. The dual-screen protector mainly protects against abnormal voltage, and the air switch is responsible for overcurrent protection. The two need to be used in combination.

Q: How to deal with frequent tripping?

A:

1. Check whether the load exceeds the rated current.

2. Measure the voltage fluctuation range of the power grid. If it exceeds the threshold of the protector, adjust the parameters or replace the model.

3. Check whether the neutral wire has poor contact (measure the neutral wire current with a clamp meter).

Q: How long is the warranty period?

A: The warranty period of mainstream brands is 1-3 years. For example, the Chint OUVR-3 series provides a 2-year warranty, and the Schneider R9 series provides a 3-year warranty.

 VII. Purchase Suggestions

1. **Family Users**: Give priority to choosing Chint OUVR-3 (digital display + rail installation) or Bull LZGQ-63/1PN (APP control), which have moderate prices and practical functions.

2. **Commercial Users**: It is recommended to choose Delixi DZ47sGQF (adjustable threshold + surge protection), which is suitable for voltage-sensitive equipment.

3. **Industrial Users**: Schneider R9C44263 (high protection + long life) or ABB SH series (wide voltage input) are more reliable.

4. **Overseas Users**: It is necessary to confirm whether the product complies with local certifications (such as UL, CE), and select a model that supports the corresponding voltage standard.

Through the above multi-dimensional technical analysis and application guidance, users can comprehensively understand the performance characteristics of the dual-screen self-resetting overvoltage and undervoltage protector, and make the best choice according to their actual needs. After installation, regular maintenance is required to ensure the long-term stable operation of the equipment and provide comprehensive protection for the electrical system.