What are the quality control measures during the installation and commissioning stages of electrical engineering?
1. First make a sample of the wiring in the distribution box and wire box. The metal distribution box door and the box should be connected with a ground wire. The wiring is neat and the crimping is firm. Multi-strand wires must be tinned before crimping. Each circuit is clearly marked. , and then fully carry out the work to prevent existing problems from being discovered after a lot of work, making rework difficult and affecting progress.
2. The connection of the grounding wire and the reservation of the grounding terminal should meet the requirements of the specification; lightning protection of the metal doors, windows, railings and large metal parts of the roof is the key, and the processes should be well connected to prevent omissions; the equipment shell should be well grounded.
3. The work is required to be carried out according to procedures. For example, all cables, plug-in busbars, wires, and equipment must pass the insulation test before power can be sent for debugging. It is strictly forbidden to send power rashly based on "experience" or "feeling".
4. Equipment operation and debugging should be carried out according to the principle of no load first and then load, and single unit first and then linkage. Adjustable components such as thermal relays should first be adjusted to the specified design values, and the reliability of the electrical and mechanical performance should be verified within the specified continuous operation time.
5. For areas with suspended ceilings, focus on checking whether the wires in the ceiling are laid through pipes; the electrical pipes should be laid out horizontally and straight; whether the junction box is equipped with a cover; whether the metal hose is too long; whether the lamps are fixed as required; Whether the pipes are equipped with separate hangers and special pipe clamps as required and should not be fixed on the suspended ceiling keels at will. When installing steel pipes, attention should also be paid to the reliable and firm connection of the joints and the continuous and reliable grounding of the electric pipes.
6. Although the debugging of dual power supply terminal switching is relatively simple when implemented, problems often arise because it is too simple, not taken seriously, or due to poor coordination between various types of work. (For example: In some projects, the backup power supply cannot carry the load because the setting value of the switch is not set according to the design requirements; the dual power supply end switching box cannot automatically switch during the backup power supply, just because the secondary circuit transfer switch is not turned on. to the automatic position; the backup power supply circuit did not check the phase sequence, and the motor reversed due to the reverse phase sequence.)
7. The control of fire pumps involves pressure reduction starting, on-site manual, fire control room manual, automatic pump starting in case of fire, main and backup mutual switching, etc., and often involves several installation and commissioning units, so it is easy for technical failures to occur. Problems in coordination and cooperation, as well as some minor defects in individual designs, affect debugging and acceptance. Electrical technicians must be familiar with the design drawings and the secondary circuit diagrams and control schematic diagrams provided by the manufacturer in advance to discover or foresee possible problems as early as possible. and deal with it. This part of debugging is very critical. Sometimes a small problem will affect the acceptance of the entire fire protection project.
