Neutral Line Filter Manufacturer, Wholesale Sichuan Neutral Line Filters

Harmonic Disturbance
1. Increase electrical load, decrease power factor, and reduce the capacity of electrical equipment, resulting in equipment waste, wiring waste, and power loss.
2. Induces capacitor resonance and harmonic current amplification, leading to damage or failure to operate of the capacitor bank due to overcurrent or overvoltage.
3. Pulsating torque causes motor vibration, affecting product quality and motor lifespan.
4. Eddy currents and skin effect cause power loss and overheating in motors, transformers, transmission lines, etc., wasting electrical energy and accelerating insulation aging.
5. Harmonic voltage enhances the electric field strength of the insulation medium in proportion to its peak voltage, thereby reducing the lifespan of the equipment.
6. Harmonics (3rd multiples) can cause excessive neutral current in a three-phase four-wire system, and in severe cases, may even lead to accidents.
7. Harmonics can alter the operating characteristics of relays, causing protective relay devices to malfunction, leading to disruptions in the operation of automatic relay protection systems.
8. Harmonics alter the rate of change and peak values of voltage or current, delaying arc extinction and affecting the breaking capacity of circuit breakers.
9. Cause measurement instruments, particularly induction-type electricity meters, to produce measurement errors.
10. Interferes with the operation of nearby power electronic equipment, industrial control systems, and communication devices, affecting their normal functioning.
Product Specifications: Harmonic Suppression Voltage Level: 380V Current: 800A Frequency: 50Hz Protection Grade: IP20 Input/Output: Rear Input and Rear Output Measurement Accuracy: 0.5S Power Supply Voltage: 85-270V Availability: Nationwide Application: Full Power Type Harmonic Compensation Times: 0-20 Times Compensation Response Time: 10ms Wiring Method: Three-Phase Three-Wire/Three-Phase Four-Wire Installation Method: Wall-Mounted/Cabinet/Drawer Voltage: 380V Harmonics: 1000A Power: 400A Noise Level: 60dB

Years ago, the harmonic mitigation industry was unheard of. To this day, when industrial sites encounter interference issues, the power management staff often reflexively believe it must be harmonics at fault. The transformation of the harmonic mitigation industry from being ignored to now being a blossoming field with various companies vying for attention demonstrates its recognition and familiarity among people. Harmonic mitigation equipment has also undergone continuous reforms, evolving from initial passive filters to today's active filters, with a focus on the zero-line filter product.

What is neutral current
Neutral Current: The current measured on the neutral cable in a normal three-phase four-wire or three-phase five-wire power supply cable is referred to as neutral current. Causes of Neutral Current: The main reasons for the generation of neutral current in a three-phase four-wire or three-phase five-wire power supply network include: ① Unbalanced neutral current caused by unbalanced three-phase currents in the load, ② Neutral current generated by the superposition of three-phase harmonics from the lighting load side flowing into the neutral ( nowadays, the excessive neutral current in three-phase four-wire or three-phase five-wire power supply is mainly due to the flow of zero-sequence harmonics into the neutral).
2. Definition and Characteristics of Harmonic Series
Zero-sequence harmonics in an electrical power system are harmonics of current or voltage with the same direction as the three-phase current or voltage vectors, consisting of harmonics at 3rd, 6th, 9th, and 3n (n=1, 2, 3, ...) orders. As they typically flow to the neutral wire, in a three-phase balanced four-wire power system, the neutral wire current is the zero-sequence harmonic current.
3. Dangers of Neutral Wire Current:
During circuit design, the neutral wire is typically much thinner than the phase wire, with large currents flowing into the neutral wire, making the following issues more pronounced. Severe overloading of the neutral wire causes overheating of the cables, accelerating insulation aging; once the insulation ages to a certain extent, it can lead to short circuits and grounding faults, causing electrical fires; zero-sequence current causes the cables, metal sheaths, and transformers to heat up, increasing energy consumption; the neutral wire's zero position drifts, resulting in voltage between the neutral wire and ground, posing a hidden danger to equipment and personal safety and interfering with low-voltage equipment (such as computer crashes, instrument malfunctions, and inaccurate electricity meters); zero-sequence harmonics can easily lead to low transformer utilization rates, and the overloading of the neutral wire causes frequent tripping; LIT Intelligent General Type Neutral Wire Current Eliminator - The LIT Power Quality Intelligent General Type Neutral Wire Current Eliminator is a new type of neutral wire current eliminator jointly developed by Shenzhen Liewu Power Quality and large and medium-sized colleges and universities, and power groups. It is mainly suitable for eliminating neutral wire current when the balance of three-phase current load is within 15%, eliminating over 90% of the neutral wire current.
4.1 Applicable Locations
Office buildings, LED screens, street lights, shopping malls, banks, scientific research, schools, sports venues, studios, etc., primarily consist of 3rd, 6th, 9th, and 15th order harmonic distortions.
4.2 Performance Features
Significantly reduces the current in the neutral wire, eliminating fire hazards caused by excessive neutral wire current.
Can simultaneously filter out harmonics 3, 6, 9, 12, and 15 current.
No filter capacitors or electronic components, with high reliability like a dry-type transformer, lifespan up to twenty years.
Effectively avoids harmonic amplification.
Avoid harmonic interference with precision equipment (such as computer crashes), which can lead to unnecessary losses.
Effectively protects overloads of reactive compensation capacitors, extending their service life.
Effectively reduces the iron and copper losses of transformers, achieving energy savings of more than 3-10%.
Enhance transformer utilization rates (due to excessive neutral current, some transformers have utilization rates below 30%).
Avoid false tripping of zero sequence protection and eliminate economic losses caused by such false operations.
Zhejiang Kefiller Fire Protection Technology Co., Ltd. specializes in high and low voltage electrical equipment and complete sets. We are seeking agents. Please call for inquiries!
5. Technical Data
The technical data listed in this table is the standard specification. Please contact us if required.
Working Conditions
Work Conditions - Relative Humidity: 90%RH
High operating temperature: 40℃
High Altitude: 2000m
Basic Electrical Parameters Rated Frequency: 50Hz
Rated Voltage: 400V
Overall Equipment Loss: ＜3W/KVA
Connection Type Three-phase four-wire system, cable or copper busbar connection
Insulation Class H (B class under normal operating conditions)
Protection Level IP30

This physical quantity is typically observed on the neutral line. I can assure you that the level of the 3rd harmonic is directly proportional to the enterprise's safety hazard index. This is because the neutral line current is composed of two parts: 1) unbalanced current and 2) 3rd harmonic current. The higher the 3rd harmonic, the higher the neutral line current, which in turn increases the fire safety hazards for the enterprise!
Working Principle
Traditionally, the solution to harmonic current on the neutral line has been to install a parallel three-phase four-wire filter to absorb and reduce harmonic currents on the phase and neutral lines. However, whether it's an active filter that reduces harmonics or a passive filter that does so roughly, both can only address harmonic current issues upstream (at the grid side) of the filter treatment point. For example: installing an active or passive filter at the low-voltage main output end of a transformer can only reduce the harmonic current entering the transformer. The harmonic current downstream (at the load side) of the treatment point cannot be effectively treated or reduced. Therefore, the interference and harm caused by the three times frequency odd harmonics superimposed on the neutral line by single-phase rectifier loads still exist. To solve the three times frequency odd harmonic problem existing in the entire distribution system, it is necessary to install a large number of filters at the end of the input lines of widely distributed harmonic source load equipment, which will significantly increase the construction volume and cost, making the cost-performance ratio too low and most users unable to bear it.
Zhejiang Kefule Fire Protection Technology Co., Ltd. has successfully developed the ZJKF-NPF series neutral current harmonic treatment devices, integrating over a decade of practical experience and technical accumulation in harmonic control. These devices are not only unique products on the market capable of treating odd-order harmonic currents at three times the fundamental frequency from the source, but also filters that can simultaneously treat odd-order harmonic currents at three times the fundamental frequency on both the phase and neutral lines in a three-phase four-wire distribution system. Hence, they are also known as phase line filters for odd-order harmonic currents at three times the fundamental frequency. The device has been widely applied in eliminating abnormal increases in neutral current caused by odd-order harmonic currents at three times the fundamental frequency, as well as in reducing busbar heating oscillation and transformer overheating noises.