The size of a sub panel for a workshop should be a minimum of 60 amps up to 100 amp power feed from your house or main service. This is assuming that you have at least a 200 amp main service. It should be 120/240 volt single phase.

How big of a sub panel do I need?

Subpanel Circuit Breaker Sizing





To calculate the breaker size, simply divide the adjusted wattage by 240 volts to find the rated amperage needed for your subpanel. Often, the result is not a common circuit breaker size. and you can simply round up to the next higher size of ​the breaker.

Can I run a 100 amp subpanel from a 100 amp panel?

Let me try and answer some of your questions. First the panels you are looking at that are rated 100A simply means you can use them for any application up to 100A. You can for example add a 60A breaker to your existing panel and protect the new subpanel with a 100A rating.

How many circuits can I put on a 30 amp subpanel?

The amount of current that is required for the connected loads can only be supported by a 30 Amp sub-panel. The maximum quantity of branch circuits can be determined with a load calculation. Two 15amp breakers or one 15amp and one 20amp can be used on a 30amp circuit.

Can you run a 200 amp sub panel off 200 amp main?

Is feeding a 200A sub from a 200A main legit? Yes, and you don’t even need another 200A breaker. The 200A breaker alread present in the panel will suffice, and so you can use a subfeed lug kit as DrSparks advises.

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.

How big can my subpanel be?

The limit is that the breaker in the main panel to supply the subpanel has to be 90 Amp or smaller.

How big of a subpanel can I install off a 200 amp service?

Even though there is no limit on the number of subpanels that you can add to a circuit, it shouldn’t exceed 160 amps when you’re using a 200 amp main panel. Always follow this guide to install subpanels effectively.

How many breakers are allowed in a 200 amp panel?



Most 200 amp panels will have 40 breaker slots but can accept more circuits with tandem breakers. 120v single-pole breakers will use 1 breaker slot, while 240v double-pole breakers will use 2 breaker slots.

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.

How much does it cost to have a sub panel installed?

between $400 and $1,750



The average cost of installing a subpanel is between $400 and $1,750, depending on the amperage and number of circuits installed. Typically subpanels have 4 to 20 or more circuits and between 100 and 150 amps.

Does a subpanel need a main breaker?

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.

Why have a sub panel installed?

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.

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.

Can I use a main panel as a subpanel?



Is it possible to use a main breaker panel as a subpanel? According to electrical-online.com, a standard load center can be used as a subpanel. The neutral bonding jumper is needed to be removed. The neutral must be out of the way in a subpanel.

Can you wire a subpanel from a subpanel?

Answer: Yes. The main electrical service panel is where branch circuits originate. A branch circuit consists of the circuit conductors between the final over-current device protecting the circuit and the lights, receptacles and equipment supplied by the branch circuit.

Does a subpanel need a neutral?

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 I run a 100 amp sub panel off 200 amp main?

Of course you can, you can add the 100 amp breaker to your 200 amp as long as it isn’t overloaded, to start adding the subpanel you must first calculate how many yards it will be from the main panel to the subpanel, there is a formula that calculates how much friction will be on the wire at the connecting distance, …