Does a sub panel need to be bonded?

Rule #3: In a subpanel, the terminal bar for the equipment ground (commonly known as a ground bus) should be bonded (electrically connected) to the enclosure. The reason for this rule is to provide a path to the service panel and the transformer in case of a ground fault to the subpanel enclosure.

Does a subpanel need to be grounded separately?





An insulated neutral must also be separate from the ground bar at the subpanel and if installed in a separate building must have it’s own ground electrode with a solid #6 copper wire attached from electrode to the ground bar. The main service panel ground bar must be bonded and the subpanel unbonded.

What are the grounding requirements for a sub panel?

Grounding for a Sub Panel Located in the Same Building



A second panel or sub panel should have the neutral and ground terminals or bars isolated from each other, this is why the main circuit feed to the sub panel must have 4 wires, with a dedicated insulated wire for the neutral and a separate wire for the ground.

Do you use a bonding screw on a subpanel?

Quote from the video:
Quote from Youtube video: But in this case. The bonding screw is that green headed screw right there. So that screw just simply threads through the neutral bus.

Does a subpanel need a separate 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.

What happens if you bond neutral and ground in 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!

Why do you not ground a subpanel?

So, why do you separate the ground and neutral in a subpanel? Because when we bond them together, it gives your neutral wire (the one carrying electrical currents BACK to the source) multiple pathways. That’s how the chassis of some equipment will become energized.

Can ground and neutral be on same bar in 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.

How do you ground a garage subpanel?

Pull 4 conductors (2 ungrounded (hot), 1 grounded (neutral), 1 grounding) (250.32(B)(1)). Grounded (neutral) and grounding bus must be separate at sub-panel (250.32(B)(1)).



  1. 2 ground rods minumum 6′ apart unless you already got another type of electrode out there. …
  2. There’s a long list of acceptable grounding electrodes.

What kind of wire do you use for a sub panel?



The cable must have a wire gauge sufficient to the amperage of the subpanel—a 100-amp subpanel requires #4 copper wires or, more commonly, #2 aluminum wires, for example. (Aluminum is often used for feeder cables because the cost is typically much lower than that of copper wires.)

When should I bond my electrical panel?

Quote from the video:
Quote from Youtube video: Now why do we bond electrical systems to neutral. And ground first of all we need a way to clear a fault if there is a fault condition.

How far can a sub panel be from the main panel?

You may not know this voltage, so it’s best to provide 4 feet. The panel must be easily accessible, so don’t install it too far above the floor; 4.5 to 5 feet is about right. The cable you run from the main panel to the subpanel also depends on the amperage rating.

When should I bond my electrical panel?



Quote from the video:
Quote from Youtube video: Now why do we bond electrical systems to neutral. And ground first of all we need a way to clear a fault if there is a fault condition.

What is difference between grounding and bonding?

Bonding is the connection of non-current-carrying conductive elements like enclosures and structures. Grounding is the attachment of bonded systems to the earth. Both are necessary to safeguard people and property from electric hazards.

Can ground and neutral be on same bus bar on a sub panel?

The answer is never. Grounds and neutrals should only be connected at the last point of disconnect. This would be at main panels only.

Why does a subpanel need 4 wires?

The neutral and ground are not bonded in the subpanel. In this setup if a hot wire coming in contact with the non-current carrying parts of the electrical system, (outlet covers, panel covers etc), the 4th ground conductor will provide a low resistance patch back to the source tripping a breaker.

How many conductors do you need for a sub panel?



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.

Do I need a neutral wire for a subpanel?

Here it is: Your ground and neutral wires definitely need to bond (or connect) together. But this is ONLY allowed in the main panel— never a subpanel, or anywhere else in the home.

What size wire do I need for a 100 amp sub panel?

The cable must have a wire gauge sufficient to the amperage of the subpanel—a 100-amp subpanel requires #4 copper wires or, more commonly, #2 aluminum wires, for example. (Aluminum is often used for feeder cables because the cost is typically much lower than that of copper wires.)

Can you feed a 100 amp sub panel with a 60 amp breaker?

You can feed a 100 Amp panel with a 60 Amp breaker. Keep in mind that the sub panel needs to be rated above the breaker size.

Can you feed a 100 amp sub panel with a 50 amp breaker?



Just wire it up. There is no problem using a sub panel that can take more current than you will ever feed it. Points to note: The cable to your hot tub will be rated for 50A (not 100A); therefore you must not upgrade the breaker in your main panel to 100A.

What wire size do I need to go 100 feet for a 100 amp service to a workshop?

For a 100 ampere circuit, the conductors will likely be required to be 3 AWG copper or 1 AWG aluminum.

How do you wire a 100 amp sub panel?

Quote from the video:
Quote from Youtube video: Type of wire if you're using six gauge or smaller wire. You can actually get multiple colors and you will have to get the correct colors.

What kind of wire do I need for a 60 amp subpanel?

In short, the wire size for a 60 amp sub-panel 150 feet away is 3 AWG gauge wire.