b737-300 electrical
 

-for b737-300 some grid locations (Grid No) are associated with Circuit Breaker No.
what doas the Grid No mean and how is it used?

The Circuit breaker panels are arranged in a grid pattern, so to locate a particular CB, a check list or MEL procedure would say H5 for example, and the CB would be in row H and be the 5th one along.
Hope this helps.

dixi188, very many thanks for your response,however the number (Grid No) is not as simple as you mentioned and some sort of more complex alpha-numerical code such as "L010" is used in WDM.so do you have any idea on specific document to be consulted to find thorough explanation of such alpha-numerical coding?