Making up your sub-panel

Now that you have properly installed your sub-panel and routed the wiring into it, you're ready to get everything connected.

Add the Ground bar

In a sub-panel, you are required to separate the grounds and neutrals. The neutral conductors must be isolated from ground at this point. In order to do this you need a separate ground bar in your panel. If your panel didn't come with one, they should be able to fix you up where you purchased the panel, just tell them you need a ground bar kit for it. Install the kit as per the provided instructions.

The feeder conductors

Remove the jacket from the cable, leave at least 1/2 inch of jacket outside the connector. Route the ground (bare or green covered) conductor to the ground bar, strip the insulation off of the end and install into the lug, tighten set screw. Repeat with the neutral conductor (white or white striped), routing it to the neutral bar. Lastly, route each line conductor (can be identified by any color other than green or white) to a line lug (the ones connected to the main bus bars) and tighten the set screws.

Strip the branch circuits

Remove the jacket from each of the branch circuit cables (remember to leave at least 1/2 inch of jacket outside the connector). As you remove the jacket, be sure to re-identify the conductors with what they are feeding. Also at this time you need to re-identify any white conductors from cables that will be used as a line conductor in a 240V load (you can color them with a sharpie, or cover them with black tape).

The grounds

Route each ground (green or bare) conductor to a spot in the ground bar, strip the insulation from the end, install and tighten set screw.

The neutrals

There are two neutrals you will not address in this step, if they are present: the neutral for a circuit that requires an AFCI breaker, and any from a circuit that requires a GFCI breaker. The rest of the neutrals can be routed to a spot in the neutral bar. Strip the end, install and tighten set screw.

Circuit breakers

Count how many circuit breakers, and of what size, you need and snap them into the panel (the outside usually connects first, then push the inside down on the buss bar). Organization of the breakers is up to you, but I usually group my 240v loads, then move to my 20A, then to 15A, and try to group like circuits together.

AFCI/GFCI

If you have either one of these, route the neutral from the breaker to the neutral bar, then route the neutral from the branch circuit to the neutral lug on the breaker.

Branch circuits

Only perform this step if you are certain that switching on the circuit breakers will not create an unsafe condition! Route each circuit conductor to its respective breaker and terminate in the breaker's lug.

Cover

Make sure you are holding the cover in the correct position! Remove each knockout needed to facilitate a breaker. Label the circuits in the proper spot on the panel cover. Install the panel cover using the provided screws.