high-voltage bridge cable fault locator
The high-voltage bridge cable fault locator is designed based on the principle of MURRAY bridge. It can be used to locate the breakdown points of various wires and cables after laying and the defect points with no breakdown but low insulation resistance value. Of course, it can also be used to locate the defect points of various cables in the cable factory.
The equipment uses switching power supply to form a high-voltage constant current source, no-load voltage 15KV, short-circuit current 50mA, high-sensitivity amplifier and galvanometer to indicate balance, and proportional potentiometer to form a balance bridge, the whole is placed at high potential, the measurement cable is specially designed The double-core high-voltage rubber cable adopts the four-terminal resistance measurement method to avoid the error introduced by the lead resistance. The cable is reliably grounded through the braided shielding layer. The operation button on the panel is at a low potential, and the bridge is operated through an insulating rod. The high voltage constant current source and bridge are integrated in a portable aluminum alloy case. Therefore, the device has high voltage, light weight, convenient operation and safe use.
Compared with the wave reflection method, the bridge balance method has no blind area, and is especially suitable for judging the breakdown point of short cables and near the end, and the operation is easy.
The output voltage is adjustable;
The shock frequency is adjustable;
With overcurrent protection;
There is no blind spot in the test range;
Signal frequency adjustment;
Zero protection.
High-voltage bridges are particularly suitable for
1. The high-resistance breakdown point of the cable after laying, especially the linear high-resistance breakdown point that is difficult to burn low-resistance, such as the linear high-resistance breakdown of the cable intermediate joint.
2. Flashover type breakdown point. After the breakdown, the constant current source can maintain the arc, a stable current flows through the bridge, and the bridge has sufficient sensitivity.
3. The defect points that have not yet broken down but have low resistance, such as the insulation defect points that have low resistance value of the cable but do not break down under the operating voltage are found by using a megohmmeter.
Due to the above characteristics, high-voltage high-voltage bridges are especially suitable for the following users:
Teams engaged in professional positioning: such as cable repair and trial classes for large and medium-sized power supply bureaus and large-scale electricity enterprises. Most of the cable breakdown points can be quickly found with a high-voltage bridge to find the approximate breakdown location. It can be used in conjunction with the wave reflection method and the fixed point meter to learn from each other's strengths and make the positioning faster and more reliable.
1. Small users: such as small power supply bureaus and medium-sized electricity enterprises. There are not many cables, the general direction is clear, the instrument is not located, the price is high, and the quality and experience of the user are required to be high, so it is not the best choice. It is a better way to choose this device, which is easy to operate and can meet daily needs.
2. Cable production plant: In the factory, it can be used to locate the breakdown point of various cables, and a digital capacitance meter can be selected to find out the disconnection point. The device is light in weight and easy to carry to the field for positioning services for cable users.
| No load voltage |
≤15KV |
| Short circuit current |
≤100mA |
| Positioning accuracy |
±(0.1%·L±1)M |
| Weight |
16 kg |
| Power supply |
AC 220 and 9V battery |
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