Abstract:

After the implementation of the new national standard technical standard for fire emergency lighting and evacuation indication system, the fire emergency lighting lines with long distribution distance have some problems, such as excessive terminal voltage drop or conservative calculation value,and small short circuit current at the end, etc. Aiming at the terminal voltage drop is too large or the calculated value is conservative,a new practical calculation method that the voltage drop of the line can be calculated accurately was proposed. Aiming at the problem that the short circuit current at the end of the line is too small, based on the fusing time curve to current characteristics of the fuse, the concept of minimum short circuit current which can be fused in a specified time was proposed, and the limit power supply distance of common conductors under safe voltage was calculated. The problem of large error in simplified calculation of voltage drop was solved. A convenient calculation method for short circuit current of emergency lighting circuit was proposed. It can reduce the hidden danger of fire emergency lighting distribution design effectively in this respect.

Key words: fire protection, A type luminaire, emergency lighting;distribution design