Understand the wire people know that the wire is three colors, divided into yellow, blue and green, for these three colors, in fact, each color represents a different, divided into the fire line zero and ground, but for many people in the differentiation of the time simply do not know how to distinguish between yellow, blue, green, how to divide the fire line zero and ground? In addition, people do not know why the ground wire, then the following for you to introduce the role of the ground wire what is it?
Yellow, blue and green how to divide the fire zero ground wire?
For domestic 220V mains power in the fire wire generally use red or brown, because these two colors are hot. Zero wire with blue or green, black. Ground wire with yellow and green two-color wire. Three-phase electric fire wire with yellow, green, red, respectively, the three phases of alternating current A, B, C.
1, wiring standards. Fire wire (L) color shall be red, yellow, green; zero line (N) color shall be black, blue; ground (PE) color shall be yellow, green two-color line. Facing the 3-hole socket, left zero, right fire, center ground.
2, install an earth leakage circuit breaker in the bus, with a light bulb connected to the fire line and zero line or fire line and ground, such as earth leakage circuit breaker action indicates that it is the ground line, otherwise it is the zero line.
3, if at home: energized, measured with an electric pen, will be bright all the fire wire. Will be disconnected from the zero line at the main switch, only connected to the fire line, the lights at home in the open position, measured with an electric pen, just not bright, now bright all the zero line. The rest are not bright all ground.
4, the simplest, take a 220V bulb, with a pen to determine the fire line, respectively, with two lines and fire line connected to the lamp head, from the brightness can be distinguished from the zero line and the ground line, the bright is the zero line, slightly darker is the ground line.
5, with a multimeter. The multimeter will be placed in the AC file 500v, hand pinch a pen, another pen were touched to the power line, there is a high voltage is the fire line, low is the zero line, the voltage is 0 is the ground line. Zero line resistance to ground is less than 4 ohms for reliable grounding. With a multimeter placed in the AC file ground 250v measurement of the fire line and zero line, fire line and ground voltage difference, the difference between the two values in the 5v or less for reliable grounding.
What is the role of the ground wire?
1, to protect personal safety
Due to electrostatic discharge is prone to generate a large number of charges, if the electrical equipment does not get proper isolation, it will be very easy to electrical appliances and human body caused by great harm, and the role of the grounding wire coincidentally is to become a high-voltage equipment and the earth between the conductor, to play to avoid us by the purpose of the damage of the electric charge.
2, lightning
Put in the past, once the occurrence of thunder and rain, poles and other equipment are often damaged because of lightning strikes, sometimes even days can not be used, so the role of the grounding wire in the role of lightning can have a very good protection, effectively extend the service life of electrical equipment.
3, to ensure normal operation
For some must have electricity to work, such as medical work, the role of the grounding wire is to avoid power outages encountered when the unexpected situation, not to be affected, still able to operate normally a small load reference potential.
Above for you is the yellow, blue and green how to distinguish between fire, zero and ground wire? What is the role of the grounding wire? After reading should have known it, in the wiring must find a professional to prevent accidents, in addition to the purchase of wires must be into the right brand, so that the use of a longer life, but also to a certain extent to ensure safety. Grounding is also for the sake of people's safety, so this aspect should not be ignored.