Control cable pairing method

In the construction of secondary circuit control cables in power plants or substations, cable pairing is a very important process. Compared with the pairing of communication cables, the main feature is that the number of cores is less (24 cores more), and single core is Unit, cable length is not large (tens of meters to hundreds of meters). In the field practice, everyone has accumulated a lot of good experience in controlling the alignment of the cable. This article makes a point of introduction and improvement based on the author's little experience and improvement to attract attention to this unnoticed technical link. Promote improvement and communication, so that accuracy and efficiency and emergency response capabilities are improved.
1. Commonly used pairing method.
1.1 General process.
The pairing of the control cable is a pair of cores one by one. Usually, first determine a common line, one end is short-circuited with the core under test and the common line, and the other end is tested with a test lamp between the common line and the unknown core until the light is on , The unknown core is determined, try the next one. During the test, personnel at both ends contacted the phone for coordination.
1.2 The selection of common wire The common wire can have multiple selection methods: one is to find a core that is obviously "different" (for example, only one or two are red) from the tested cable; the second is to use shielding The shielding layer of the cable; the third is the use of a grounding network, with grounding screws on both ends (this method is prone to poor contact and may also have interference. It is best to only use it to determine a small number of core wires such as public wires and telephone lines. ); Fourth, pull a temporary line.

1.3 Test lamp.
The test light is a "disconnect indicator", called "disconnector", which is made by connecting two test wires acting as switches with a dry battery (two 1 \\\\ #) and a hand bulb. Its advantages are simple, easy to make, and its disadvantage is that the bulb is easy to burn and consumes electricity. When replacing the battery, it is tantamount to re-making. There is also a DC buzzer, which is also powered by dry batteries, and emits sound when the line is connected. The disadvantage is also power consumption and poor contact. Many people now use a digital multimeter with a disconnection test function as a disconnector. The method of prompting connection is an indicator and a sound. The effect is good, but the price is expensive.