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JZGB Three-phase Combined Over-voltage Protector

2018-04-09 14:12

Product Introduction

The three-phase combined over-voltage protector of our company is also known as Trident-type over-voltage protector, referred to as JZGB is designed for the shortcomings of conventional surge arresters with unique connection and structure of the over-voltage protection. Compared with the conventional arrester, the three-phase combined over-voltage protector has unparalleled advantages. It is widely used in electric power, metallurgy, chemical, coal, light industry and other industries to protect the transformers, switches, buses, motors and other electrical equipment atmospheric over-voltage and operating voltage over the ideal device.

Product Usage

Three-phase combined over-voltage protector is mainly used in power supply system of power supply enterprises and electric enterprises to protect the electrical equipment such as transformers, switches, bus bars and electric motors etc., and can limit the atmospheric over-voltage, the breaking over-voltage caused by vacuum circuit breakers and over-voltage operations, phase to phase and phase to grounding over-voltage can play a reliable role in limiting.

Principle, Characteristics

Three-phase combined over-voltage protector consists of four discharge gap and zinc oxide resistor in series. As shown on the right diagram, ZnO is a zinc oxide non-linear resistor and CG is a discharge gap. Due to the symmetrical structure, any three can be respectively connected A, B, C three-phase, the other phase connects grounding. Three-phase combined over-voltage protector with other similar products unparalleled features:

1, Using zinc oxide non-linear resistance and discharge gap series structure, so that the mutual protection of each other, the discharge gap makes the charge rate of zinc oxide resistance is zero, the nonlinear characteristics of zinc oxide makes discharge gap immediately quenches arc and no freewheeling after the action. The discharge gap is no longer bear the task of arc extinguishing, the product action life can be increased to 104-105 times.

2, The voltage impact coefficient is 1, discharge voltage values are equal in a variety of voltage waveform. It is not affected by all kinds of overvoltage waveforms, over-voltage protection value is accurate and the protection performance is excellent.

3, JZGB discharge instantaneous value and the residual voltage after the action is similar, no-cut wave, more conducive to the protection of equipment turn-to-turn insulation.

4, The use of four-star connection method can greatly reduce the interphase over-voltage, compared with the conventional arrester, the interphase overvoltage over 60-70% reduced, greatly enhance the reliability of protection.

5, The JZGB with silicone rubber jacket and high-voltage cable outer lead structure has the advantages of easy installation, strong sealing, small volume, vibration resistance etc. It can be directly installed on the chassis of the switchgear or the PT cabinet.

6, Ambient temperature 40-+60, altitude less than 2000m (higher than 2000m, please specify when ordering).

7, When the system occurs intermittent arc grounding over-voltage and ferromagnetic resonance over-voltage, the energy is less than 400A2ms square wave impact energy, JZGB can play a protective role.

Shape, Structure

In order to facilitate the installation in the handcart and other places, JZGB uses three column-shaped structure to bury the grounding phase in the base, and connect it to the ground through the external bolts. The three-phase interphase distance between A, B and C is 131 mm, which basically corresponds to the user's bus bar head or switch head.

This structure is not only beautiful, but also the high voltage cable between the JZGB body and the device head is basically parallel straight line, without cross collision, it is conducive to safe operation.

Experiment, Maintenance

Power frequency discharge voltage test

According to JZGB power frequency discharge test wiring diagram (below) will be connected to the relevant instruments and equipment, of which ZT is voltage regulator, ST is 5KVA test transformer below, V is high voltage meter, uA is digital micro ammeter.

The test voltage is added to the A/B, A/C, B/C, A/D, B/D and C/D terminals of the tested products respectively, and the output voltage of the test transformer is slowly regulated. Meanwhile, the voltmeter and the digital micro ammeter are observed. JZGB did not break through the discharge, the digital microampere meter readings almost no change; when the experimental transformer output voltage reaches the JZGB action value, JZGB gap breakdown discharge, digital microampere table larger changes, and was unstable, At this point, the test transformer high voltage output value is the value of the power frequency discharge JZGB.

Experimental Notes

1. Indoor JZGB in the working amplifier test, the JZGB should be placed on the iron plate, the iron plate must be reliably grounded, iron plate surface should be slightly larger than the bottom surface of the XBGB:

2. When JZGB working discharge test, it should be uniformly boosted. When JZGB discharge, the regulator should be immediately back to zero, and cut off the power supply, it is forbidden to continue to increase the voltage after discharging, so as not to damage the protector.

3. The user in the test if you find that the value of its work-force exceeds the value specified in the parameter list of 90%~120%, you should carefully check whether the wiring is correct, the meter is accurate, the regulator output is normal, the iron is reliable grounding, whether the power has higher harmonics. If the test data is correct, it is beyond the allowable range, please contact with us.

4. When the user tests other electrical equipment insulation, JZGB should be lifted from the device.

5. In the test, only the internal gap discharge, any part of the peripheral must not have flashover.

Operation and Maintenance

1. The air distance between high voltage lead and other equipment should be greater than 5cm when this product is installed.

2. The product should be done every one to two years of preventive PA test, at the same time JZGB surface ash.

Special Statement

Indoor JZGB uses a composite silicon rubber coat with a distance of 131mm.

Ordering Instruction

1. The user must specify the length of JZGB high voltage cable (the longest 600mm) and the line nose aperture when ordering.

2. If the counter needs to be installed on the cabinet door, we need to specify the length of the signal line between the ZGB body and the counter of the cabinet counter. The cabinet also need to provide 220V AC or DC power supply.

3. If there are special requirements for the system voltage or interphase distance, the production can be designed according to the requirements of the user.

Electrical parameters table of 3, 6, 10KV system for indoor

Electrical parameters table of 3, 6, 10KV system for outdoor

Electrical parameters table for 35KV system (Continuous operating voltage: 42KV, 2ms Rectangular)

Parameter table of motor neutral overvoltage protector

Shape and Installation Dimensions

Type of Indoor

The product can be installed in a variety of different types of switchgear, these products in addition to the switch cabinet directly "A" and "C" three-phase and grounding phase ("D" phase) is the four line of the nose for the bare conductor, the other part is enclosed by the insulator. Therefore, the relative distance between them (or the cabinet) and the installation space to the cabinet should be relatively small (generally not less than 5cm), which can be directly installed in the handcart tray of the switch cabinet or PT cabinet.

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