Your power company customer service will have to explain the rules they enforce. This is generally a published document, and may be available online. The rules vary widely from company to company, even localities within one company can vary.
The Los Angeles area that you are in will have an AHJ (Authority Having Jurisdiction). You will have to contact them for the permit and to have the work inspected. This is not changing a light bulb.
The wording of your questions causes me to suspect that if you are an electrician, as you claim in your ECN Profile, that you are very early in your education and experience. Perhaps one of your teachers can visit the site of your Zinsco panel.
Since you seem to be compelled to Do-It-Yourself, it is important to underscore that you are in the deep end of the pool. From your questions, it is also apparent that
your Zinsco panel is in need of immediate attention. DIYers are responsible for educating themselves, and this includes contacting the proper authorities (the power company and the electrical inspector), pulling a permit and obeying the rules. Hire a local electrician to consult with you while examining your Zinsco panel. Record the conversation (with their permission). . .the amount a data you will receive will be large. No amount of note taking will suffice.
Lastly, review the first paragraphs of this site's
[b]Rules, Policies and Disclaimers[/b]
