National codes for electrical panel include using anti-oxidant compound on aluminum conductor terminations, and allowing adequate working space around live parts that carry up to 150 volts. Code 240-24 states that electrical panels shall not be located in bathrooms or close to materials that ignite easily. Article 408 in the code outlines the requirements for switchboards and panels. Local building authorities can provide complete information on electrical codes for the area.
When working on a panel that is connected to a delta-connected high-leg system, replace the high-leg conductor in its original location once the work is complete. This avoids accidentally connecting 120-volt circuits to the high leg.
The code also states that all circuits and modifications on a panel should be clearly marked. Spare positions should be identified as such, and all identifications for a panel should be listed in a directory inside the door or on the panel board's face.
Codes for general rooms in houses include requirements that wall receptacles are placed every 12 feet, and on every wall space that is over 24 inches wide. Hallways that are longer than 10 feet must also have at least one receptacle. All receptacles on kitchen countertops must have ground fault current interrupters, and they must not be placed face-up on the countertop. There must be at least two branch circuits to supply the countertop receptacles.