“3” – the three-level distribution system shall be equipped with general distribution box, distribution box and switch box.
The switch box shall be equipped with special disconnector and leakage protector.
Temporary electricity on the construction site plays a key role.
Today, I will share with you the five laws of dry goods – temporary power consumption on the construction site.
“5” – TN-S three item five wire power supply system must be implemented in the special neutral point directly grounded power system on the construction site of five core cable.
The colors of L1 (a), L2 (b) and L3 (c) phase sequences are yellow, green and red respectively; Working zero line n is light blue; The PE of the protection zero line is a green / yellow two-color line, and the green / yellow two-color line is not allowed to be used as the load line under any circumstances.
Remember to share them with your friends after reading them.
“2” – two-level protection of temporary electricity.
There is no long talk.
Simply summarize the key points of “12345” to help you better understand and operate.
How to do this work well is something that every engineering person should know well.
It’s not enough for you to read these knowledge points once.
According to the power transmission sequence of main distribution box → distribution box → switch box, a complete three-level power consumption (distribution) system is formed.
Each electric equipment must be equipped with its own special switch box.
More importantly, you can work in strict accordance with the specifications.
“1” — a circuit on the construction site, the temporary power on the construction site must be uniformly organized and designed, with a unified temporary power construction scheme, a power source and a temporary power construction, installation, maintenance and management team.
No matter engineering equipment, construction machines and tools, on-site lighting, construction installation or daily life are inseparable from electricity, and construction temporary electricity is one of the assessment contents of safety production standardization of construction enterprises.
In addition to neutral connection, leakage protection device must be set at the head end of equipment load line.
The power distribution box and switch box shall be installed in dry, ventilated and normal temperature places, away from places vulnerable to impact and strong vibration of foreign solids, or for environmental protection.
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It is strictly prohibited to pull and connect lines without permission and take power from multiple heads.
These are the four installation principles of “one machine, one box, one gate and one leakage” in the specification requirements.
In this way, the power distribution level is clear and easy to manage and find faults.
In order to correctly distinguish the phase line, phase sequence, zero line and protection zero line in the cable conductor, and prevent misoperation accidents, different safety colors shall be used for the conductor.
The main distribution box shall be located near the power supply area.
What should we start from when we just enter the cost industry?..
It is not allowed that the same switch box and the same switch directly control more than two electric equipment.
Leakage protector must be installed in the switch box.
At the same time, a leakage protector must be installed in the switch box.
“4” – four principles for the installation of electrical devices.
The model and specification of the cable shall be five core cable.
The distribution box shall be installed in the area with relatively concentrated electrical equipment or load.