QA

How To Wire A 30 Amp Sub Panel

What size wire do I need for a 30 amp sub panel?

You need 10-gauge, three-conductor cable to wire a 30-amp subpanel. This cable has two hot wires (usually colored red and black), a white neutral wire and a ground wire, which is usually bare but could be green. It carries electricity at 240 volts, so you must treat it differently than regular 120-volt electric cable.

Does a 30 amp sub panel need a ground rod?

your main panel should have a ground rod on it (and/or be grounded to your water main), so there should be no need for you to use another ground rod.

Can you run a sub panel off 12 2 wire?

The good news is that you can run new wires as needed – that’s the bonus of having conduit. For a proper subpanel, you should have 2 hots + neutral + ground. Ground and neutral separate from each other (remove the bonding screw if there is one and put neutral and ground on separate bars).

How many breakers can you put in 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.

How far can 10-gauge wire carry 30 amps?

10-gauge wire can accommodate a 30-amp breaker until you reach 150 feet. At 150 feet or more, you should get 8AWG or 6AWG wire.

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.

Do you need a grounding rod on a sub panel?

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.

Does a subpanel need a separate ground?

Code requires subpanels to have a ground connection that’s independent of the main panel’s. Because the ground and neutral bars are separate, all the grounding conductors have to go the grounding bus and all the neutral conductors to the neutral bus.

How far can a subpanel be from the main panel?

Looks like 1.5″ EMT so that would mean that the distance between the raceways need to be a minimum of 9″. This allows for the conductors to be installed without damaging them. Also that appears to be a compression EMT connector that connects the box to the sub-panel (same as the one on the main panel).

Does a subpanel need a neutral?

3 Answers. 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.

How many wires do I need for a subpanel?

A subpanel requires two hot wires connected to a 240-volt double-pole breaker in the main panel. It also needs a neutral wire and a ground wire. The cable used for this run is known as a “three-wire cable with ground.” The two hot wires, called feeder wires, will provide all of the power to the subpanel.

Can you wire a subpanel with 3 wires?

Grounds and neutrals were isolated to provide separate paths back to the panel. Another way to wire a subpanel was with a three-wire feed; two hots and a neutral, with grounds and neutrals connected together at the subpanel. In this case, the grounds and neutrals have to be connected together.

How much does a 30 amp breaker cost?

The average cost to install a new circuit breaker is $187. The cost is as low as $130 for 15 amp to 30 amp breakers and as high as $280 for breakers up to 200 amps or when the circuit breaker is an older one with limited availability.

How many outlets can be on a 30 amp circuit in a garage?

20 outlets for 30 amp breaker as a rule of thumb of 1.5 amps per outlet.

How do you size a subpanel?

Subpanel Coverage Area Measure the length and width of each room and multiply them together to find the square footage of the room. Add up the square footage of all of the rooms to find the total square footage. Multiply the total square footage by 3 (watts) to complete the calculation.

What can I run off a 30 amp breaker?

Electric dryer, electric oven, medium or small A/C unit, electric range, 5 HP air compressor, electric arc welder, level 2 electric car charger (30 amp model), small electric heater, small electric instantaneous hot water heater, small hot tub, pool pump (3–5 HP).

What size wire do I need to run 300 feet?

for 300 feet for 100 amp rated service I would use Aluminum direct burial 1/0-1/0-1/0-1/0, the forth can be as low as #4 for the ground (but also in conduit, even if in conduit must still be rated underground wire and required by code also) Also note the size wire the breaker can handle, cannot cut strands to make fit, Jul 28, 2014.