When should I add a subpanel?

Subpanels are usually used to extend the wiring for multiple branch circuits to a specific area of a home or to a building at some distance away from the main panel. A garage, outbuilding, or a room addition might be a place to put a subpanel.

Is a sub panel required?





Electrical subpanels are added for 3 distinct reasons; space, convenience or efficiency. As mentioned above, if you are attempting to add new electrical circuits and your main panel is full, it is then that you should have a subpanel installed by a licensed electrician.

Do I need a breaker box in my shed?

If you are only running one circuit to your shed, then you won’t need a subpanel. You will, however, need a shut-off switch where the power enters the shed. This can simply be a light switch that controls all outlets and fixtures in the shed.

How do you install an electrical sub panel in a garage?

Youtube quote:Turn it off next I found a nearby stud and pre-drilled holes for a plywood backer to map the sub panel. On. These two screws are for actually mounting the Sun panel.

How do I add a subpanel to my electrical panel?

How to do it

  1. Mount Subpanel wiring. Mount Subpanel. Mount the subpanel about a foot away from the main service panel. …
  2. panel ground bus bar using screwdriver to ground wires. Plan Route. …
  3. Connecting Feeder Breaker Wires. Strip Wires. …
  4. Subpanel Hot Bus Bar. Connect Wires. …
  5. Subpanel New Circuit. Finish Connecting Wires.





Is a main breaker required in a sub panel?

The subpanel may be equipped with a main breaker to allow for power interruption without having to go back to the main panel, but it is not required to have a main shutoff circuit breaker, since the feeder breaker back in the main panel serves this function.

Do subpanels need inspected?

And not catching it in time could lead to larger, more expensive, and more devastating electrical issues in the future. A professional inspection by a trusted local electrician can provide you with the insight and experienced awareness you need to maintain your electric subpanel, and catch issues before they develop.

What is the benefit of a sub panel?

An electrician might add a sub panel to take the load off of the main circuit breaker panel. This can prevent overloading the electrical system and tripping circuit breakers or melting fuses. Sub panels are also used to separate the electrical needs of specific areas.

Can I use a main breaker panel as a subpanel?



There’s no problem with having a main breaker in a subpanel. It’s required if your panel is in a separate building and has more than six breakers, but there’s nothing prohibiting it in any other case.

Does a subpanel need a ground rod?

Yes, any sub panel outside of the main building requires it’s own ground rod and a ground wire back to the main building. And yes, a sub panel in the same building as the main does not need a ground rod – only the ground wire.

How far can a subpanel be from the main panel?

The right feet would be between 4.5 to 5 feet.



The cable running from your main panel to the subpanel depends on the amperage rating. For instance, for a 30A panel, use a 10 AWG, three-wire conductor.

Does a subpanel in a detached garage need a ground rod?



A detached building with a subpanel needs its own ground rod, regardless of if there are three wires or four wires feeding it. The earth is a very poor conductor.

How do you run a sub panel on a detached garage?

The sub-panel can be grounded at the garage. You will have to install a 6 foot ground bar outside the garage and run a ground wire from the sub-panel box to the ground rod. The ground wire does not have to be in a conduit. Remember, you’re working with electricity, so follow good safety procedures.

Why does a subpanel need 4 wires?

The current NEC code requires a 4-wire feeder so there is a separate grounding connector between the Main and Sub panels. The neutral and ground are not bonded in the subpanel.

Why are neutrals and grounds separated in a subpanel?

With ground and neutral bonded, current can travel on both ground and neutral back to the main panel. If the load becomes unbalanced and ground and neutral are bonded, the current will flow through anything bonded to the sub-panel (enclosure, ground wire, piping, etc.) and back to the main panel. Obvious shock hazard!

Do you bond neutral and ground in subpanel?



When Should Grounds & Neutrals Be Connected in a SubPanel? The answer is never. Grounds and neutrals should only be connected at the last point of disconnect. This would be at main panels only.

Should neutral and ground be connected in sub-panel?

The neutral and ground MUST NOT be bonded at a sub-panel. They should only be bonded at the main service panel. If you bond them anywhere other than the main service, the neutral return current now has multiple paths, including though your ground wire.

Can you connect ground and neutral together?

No, the neutral and ground should never be wired together. This is wrong, and potentially dangerous. When you plug in something in the outlet, the neutral will be live, as it closes the circuit. If the ground is wired to the neutral, the ground of the applicance will also be live.

What happens if neutral touches ground?

Connecting the neutral to the ground makes the ground a live wire. The neutral carries the current back to the panel. But the ground doesn’t carry a charge, not unless something has gone wrong (such as a short circuit) and it has to direct wayward electricity away from the metal case of an appliance.

Can the neutral wire shock you?



Often, the neutral wire is very close to ground potential, and you are too. So, often, there is not enough voltage to give you a shock.