There are three main measures to prevent or reduce electrical interference.
1. Ground a spare core of the control cable
Practice 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, and the cost of the cable is slightly increased.
2. Do not use a control cable for circuits that have serious consequences when electrical interference occurs.
These include: (1) weak current signal control loop and strong current signal control loop; (2) low level signal and high level signal loop; (3) each phase weak current control loop of the AC circuit breaker split-phase operation. Use the same control cable. However, if each pair of back-and-forth wires of the weak current circuit belong to a control cable that is not the same, it may form a ring arrangement when laying, and the electric potential will be induced under the cross link of the electromagnetic wires of the similar power source, and its value may Low-level parameter interference has a large impact, so it is advisable to use a control cable for the round-trip conductor.
3.Metal shield and shield ground
Metal shielding is an important measure to reduce and prevent electrical interference, including overall shielding of cores, sub-shielding, and double-layer overall shielding. The selection of the metal shielding type of the control cable should be based on the comprehensive interference suppression measures according to the strength of the possible electrical interference effects to meet the requirements of reducing interference and overvoltage. The higher the requirements for anti-interference effect, the greater the corresponding investment. When steel tape armor and steel wire braid are used for shielding, the price of the cable increases by about 10% to 20%.