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After the control cable is in operation, measures to prevent or reduce electrical interference mainly include three aspects:
1. The practice of a spare core grounding of the control cable has proved that when a spare core in the control cable is grounded, the amplitude of the interference voltage can be reduced to 25% to 50%, and the implementation is simple, but the cost of the cable is increased only slightly.
2. Circuits with serious consequences for electrical interference do not use a single control cable which includes:
(1) weak signal control loop and strong signal control loop;
(2) The loop of low level signal and high level signal;
(3) The same control cable should not be used for weak phase control loops of AC circuit breaker phase-phase operation. However, for each pair of return conductors of the weak current loop belonging to control cables that are not of the same root, it may form a ring arrangement when laid, and the potential may be induced under the electromagnet wires of similar power supply, and the value may be for weak current loops. Low-level parameter interference has a greater impact, so it is advisable to use a single control cable for the return conductors.
3. The country's wire and cable industry has also had a good market opportunity. Wire and cable companies around the country have seized the opportunity to welcome the new round of urban-rural power grid construction and transformation.
Dual-protected currents, voltages, and two systems that require enhanced reliability, such as DC power supplies and trip control loops, should use separate control cables.
Control cable performance characteristics:
1. DC resistance: 20°C, 0
4mm copper wire, less than or equal to 148Ω/km, 0.5mm copper wire, less than or equal to 95Ω/km.
2. Insulation electric strength: 1min1kv between conductors does not penetrate the conductor and the shield does not break down for 1min3kv 3. Insulation resistance: Each core is grounded to the rest of the core, the control cable is greater than 10000MΩ.km, and the HYAT cable is greater than 3000MΩ.km.
4. Working Capacitance: Average 52±2nF/km 5. Far-end crosstalk defense: When 150kHZ is specified, the average power of the specified combination is greater than 69dB/km. The difference between the performance of power cables and control cables Power cables are used to transmit and distribute large-capacity power in the backbone of the power system. The control cables transmit power from the power distribution point of the power system directly to the power connection lines of various appliances. The rated voltage of the power cable is generally 0.6/1kV and above, and the control cable is mainly 450/750V. The power cables and control cables of the same specifications are shielded and shielded at the time of production. Grounding Metal shields are important measures to reduce and prevent electrical interference, including total shield, split shield and double-layer total shield of the core. The selection of the metal shield type of the control cable shall be based on the influence of the possible electrical interference and shall be included in the measures for comprehensive suppression of interference.
Control cable performance characteristics
Usage characteristics: Working temperature: Long-term use 200 °C Short-term use 1000 °C 90 minutes China's sustained and rapid economic growth, providing a huge market space for cable products, the Chinese market is a strong allure, making the world focus on the Chinese market In the short decades of reform and opening up, the huge manufacturing capacity created by the Chinese cable manufacturing industry has made the world impressive. With the continuous expansion of China's power industry, data communications industry, urban rail transit industry, automobile industry and shipbuilding industry, the demand for wire and cable will also grow rapidly. The wire and cable industry in the future will have enormous potential for development. The Wire and Cable Financial Crisis In November 2008, in response to the global financial crisis, the government decided to invest 4 trillion yuan to stimulate domestic demand, of which approximately 40% was used for the construction and transformation of urban and rural power grids. Power cable insulation and sheath thickness is thicker than control cable.