Service box with no neutral bar


You have a neutral bar. You don't have a ground bar. Your panels look exactly like mine, which feed all EMT metallic conduit, and the conduit is the ground path. Care for it kindly, fix gaps immediately.

Your main panel has a neutral bar which appears to be all-metal and by nature bonded to the panel box (which is ground), which is both allowed and required in a main panel.

Your sub-panel has a neutral bar which is insulated from the panel box aka ground, which is required in a sub-panel.

Beware, on an isolated neutral bar, there are often special screws, usually green, which screw through the neutral bar to bond it to the case (ground). You should take care that there are none of those on a sub-panel; on a main panel I would "belt and suspenders" that by also adding a bonding...

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A distribution board (also known as panelboard, breaker panel, or electric panel) is a component of an electricity supply system that divides an electrical power feed into subsidiary circuits, while providing a protective fuse or circuit breaker for each circuit in a common enclosure. Normally, a main switch, and in recent boards, one or more residual-current devices (RCD) or residual current breakers with overcurrent protection (RCBO), are also incorporated.

In the United Kingdom, a distribution board designed for domestic installations is known as a consumer unit.[1]

North America[edit]

An American circuit breaker panel featuring


circuit breakers

In a North American distribution board, the circuit breakers are generally positioned in two columns. Circuit breaker panelboards are always dead front, that is, the operator of the circuit breakers is unable to contact live electrical parts. During servicing of the distribution board...

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I'm adding a new grounding bar to my service to complete a much-needed panel reorganization to accomodate replacing my 60+ year old wiring with new NM cable, AFCIs for the kids room, etc. Plus the previous owner seemed to 'abandon ship' on projects before their time (found wire-nut connections plastered over in the walls with no boxes, improper ground bonds to boxes, bare, energized wires nailed to joists in the basement, etc.)

I ran out of space on the neutral bar in the main service for the returns and ground wires. Note that I DID NOT overload the panel with tandem breakers or anything goofy like that -- it seems insufficient from the manufacturer -- the neutral bar was short spaces after the original installer added water pipe and ground rod bonds.

So I am connecting the original panel ground bar to the neutral bar with a #6 jumper, and adding a third ground bar to the panel (also connected to the neutral with a #6 jumper -- I am edgy about fault currents on...

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I know there is enough support because their is a 30amp that is not being used. Replacing this with a 20amp since AC only take 110v.

No, you don't really know that. There is a calculation you run through involving major loads like dryers, furnaces, and ACs along with the overall square footage. The total amperage of the breakers in a box often greatly exceeds the capacity of the service. If the 30 amp circuit you're removing is an unused or lightly used circuit, and you're adding a 20 amp AC circuit, you could easily exceed the system capacity.

At the very least, call the city (or whatever authority applies) and ask about adding the circuit. They will usually let you talk to an inspector about what you need to do. These guys may be gruff or short, but ultimately they just want things done properly. Electricity is especially important because improper wiring causes fires.

I'm guessing you're adding a dedicated circuit for a window AC. If so, that wouldn't need the...

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Neutral bars are widely used in residential and commercial electrical service panels to terminate all those white 'neutral' or 'return' wires from the many load circuits in the building.

The black 'hot' wires are protected from overload by circuit breakers in the panel which typically sense the current in the 'hot' wire and 'trip out' if current is exceeded for too long. Current sensing is usually by an element in the circuit breaker that heats up when current is too high. As the element heats more for higher currents and gathers more heat when currents exist for extended overload periods, it mimics the wiring in the buildings circuits which would themselves heat up, causing a potential fire hazard.

The heating effect in the circuit breaker is used to trigger the spring loaded circuit breaker 'trip', turning off that circuit using a bimetallic "hair" trigger to release the spring energy holding switch contacts closed, when that certain total heating effect is...

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Determine the maximum power that will be drawn on the new circuit. Divide the total number of watts by 120 (or 240 for a 240-Volt circuit). The result is the maximum current, in amperes (amps), for the circuit.


Select the proper gauge conductor for the maximum current of the circuit.Select a 14 AWG conductor for a maximum current up to 15 amps. Select a 12 AWG conductor for a maximum current up to 20 amps. Select a 10 AWG conductor for a maximum current up to 30 amps. Select an 8 AWG conductor for a maximum current up to 50 amps.


Purchase the correct circuit breaker.You must use a circuit breaker that is approved for use in your service panel. In most cases, you must use a circuit breaker made by the same manufacturer as that of the service panel. Select a circuit breaker with a current rating that does not exceed the rating of the circuit. For example, if a circuit is wired with a 12 AWG conductor, only use a circuit breaker rated for 20 amps...
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The neutral (white) service entrance conductor should be attached to a terminal in the service box, not in the distribution panel.

A neutral wire that passes through but doesn't terminate in the service box is an installation error.

The service box is the point in the electrical system where the neutral and grounding systems are supposed to come together. If the neutral wire bypasses the service box, the electrical system is not as safe as it should be, because the neutral and ground systems are not connected (balanced), at least not at the proper spot.

Check that the neutral service conductor is attached to a terminal bar in the service box. There will usually be a white wire, also attached to the terminal bar, which carries on to the distribution panel. There should also be a ground wire attached to the terminal bar directly, connected with a jumper, or bonded by the design of the box to the neutral wire. The ground wire connects to a...

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A grounding bar is most often located in the breaker panel. This is where all your grounding conductors are landed. If the panel is your primary service panel, neutrals and grounds can both be landed there.

The NEC (US) requires that all service equipment be bonded together. This includes your meterbox. To most people bonding and grounding look alike but they serve different purposes. In most cases this bonding consists of a #6 AWG solid copper conductor connecting your service panel to your meterbox and also whatever you happen to be using as a grounding electrode, usually a water pipe and ground rod.

Consult a competent electrician for what is required in your area. I was on a job once where the city inspector expected this bonding conductor to be run with the service conductors inside the same conduit, which is what I would expect. But the power company for the same job required it to be run outside the conduit which is acceptable practice. Both were right,...

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I did see some ground bar kit information on the Cutler-Hammer web site (by the way, my panel is a BR2030B150), but I was unsure of two details.

1. Whether I could just use a ground bar kit or whether there was something specific for the neutral bar (they looked alike, but...)

2. How I would "bridge" the two bars together. Perhaps this is something the kit addresses. However, the CH documentation has, on the whole, been pretty poor, so I'm skeptical. Do you just use a large wire (small gauge) connecting one bar to the other, in essense daisy chaining them together, or is it more sophisticated than that?

I did read on the panel that multiple wires are permitted in one hole on the ground bar, but it had a generic caveat about doing so on the neutral bar. As it was unclear, not saying specifically that it was permitted on this panel, I wasn't sure if that would be okay.

More information as a follow-up: I can tell you that I have only neutral (white) wires...

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An electrical conductor, usually in the form of a metal piece, is used to connect two or more circuits in a panel or fuse box also is known as an electrical bus bar. Bus bars may be surrounded by insulation or is supported on insulators. They are sometimes connected to one another and to other electrical components by clamp, bolted or welded connections. Busways are long bus bars that have a protective cover. Bus bars are normally found inside panel boards or switchgear. Many times when one takes on a job to replace electrical bus bar connectors, they run into technical issues and may need to ask questions.

Listed below are a few questions answered by the Experts on problems related to bus bars.

Is this electrical bus bar wiring correct?

Case Details: The main bare ground cable is connected to the neutral bar in my panel. The heavy white cable is connected from the neutral bus to the ground bus and both neutral and ground circuit lines are connected to the...

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With the panel door open, you can access all the circuit breakers or fuses in the panel. Typically, one of these panels feeds the entire house but you may have a situation where there is another "sub-panel" to serve a specific area such as an addition or new kitchen.

The circuit breakers are stacked in the panel and are controlled with a lever that places it in the "On" or "Off" position. You'll also see a large double pole circuit breaker at the top of the panel called the... "Main". It controls all the power to the circuit breakers below it.

Often there are stickers to be placed next to each breaker or a sheet adhered to the inside of the panel door that has space to identify the circuit served by a particular circuit breaker.

With a service panel having a fuse box, you'll have a number of screw in fuses instead of circuit breakers but the function of the electrical service panel is the...

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OEM Load Center Parts Program - GE Industrial …

... GE OEM Load Center Parts Program 2 ... Convertible, Main Breaker and Commercial Load Centers ... Neutral Bar OEM Interior without·


... 120 / 240 VAC SINGLE SPLIT PHASE & MULTI-WIRE BRANCH ... from the Neutral terminal Bar in the Service Entrance panel / ... breaker. The Neutral ...·


... grounded/neutral conductor to the distribution panel enclosure, to the equipment grounding conductors, ... SYSTEM BONDING AND...·

Loadcenters and Circuit Breakers - Eaton

... breaker directly to the neutral bar, eliminating the need for wiring a pigtail. Grounds In service entrance...

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Author Information Topic: Adding a neutral/EG bar to a service panel Member

Name: Wally King
Location: Illinois
Title: Inspector
In Trade Since: 1995
Registered: Dec 2002
Total Posts: 3

posted December 02, 2002 at 11:54 AM Is it necessary to add a bonding wire (#4 for 200 amp)from the new bar to existing neutral bar? Or would it be OK to depend on the metal cabenet to transfer the neutral current? Thanks Wally



Name: Steve Mancuso
Location: Vermont
Title: Contractor
In Trade Since: 1985
Registered: Oct 2000
Total Posts: 1676

posted December 02, 2002 at 04:33 PM interesting question.

does 250.28 apply to this?



Location: West_Virginia
Title: Electrician
In Trade Since: 1973

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Place a rubber mat on the ground beneath the home's breaker box. Stand on the mat, and open the breaker box's front cover. Turn off the box's main circuit breaker, as well as all individual circuit breakers. Loosen and remove the screws holding the box's inner cover in place, and remove the inner cover, using a screwdriver. Note that the terminal connections are now accessible. As an added safety precaution, do not touch any terminal connections in the breaker box by hand, especially the main power cables running into the box, and the lugs they connect to -- though the terminal connections on the individual circuit breakers will be dead, the bare power cable ends on the main power cables and lugs they attach to will still be live, and the power to them cannot be switched off.

Look for the circuit breaker that will be replaced. Loosen its terminal screw labeled "line power," and pull out the black or red wire. Loosen its terminal screw labeled "load neutral" and pull out...

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In your home—in everyone’s homes, in fact—the seat of electrical power takes an unassuming form. Concealed by a nondescript metal door, the breaker box doesn’t look very impressive, but it’s the reason you can turn on the lights, the blender, the air conditioning, and the TV. The breaker box, or service panel, operates as a central relay point: It takes power from the street, then feeds that power to the different electrical outlets and hard-wired appliances throughout your residence.

Most people open the breaker box only when there’s a problem—for example, when a circuit needs to be restored after tripping. And that’s the way it should be. Homeowners are wise to be hands-off with electrical elements, especially those they don’t understand. Make no mistake: The breaker box is dangerous. Hire a licensed electrician if you think the panel needs attention. The goal of this article is merely to explain a bit more about all of those mysterious...

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Hi Russ,

Thank you for your question regarding the separation of the ground bar from the neutral bar in an electrical sub-panel, it is our pleasure to help.

The difference between a ground wire and neutral wire is often misunderstood. The problem primarily comes from the inappropriately named “neutral” wire. There is nothing neutral about a neutral wire. It is a current-carrying conductor, just like a hot wire and has all the potential for danger and should be treated with the same respect.

Consider the schematic for a flash-light. Your typical flashlight consists of a battery, a switch, a few wires, possibly a fuse, and a light bulb. Let’s ignore the switch, as it doesn’t relate to the point we are trying to make. In a flash light without a switch, you would see a black wire running from the battery to the light bulb, and a white wire running back from the light bulb to the battery. The black wire would represent the “hot” wire, and the white wire would be...

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This is probably going to make some you roll over

, but I'm just starting out as a home inspector and am having difficulty understanding the ground/neutral connections. I see the neutral going to a neutral bar and the ground going to a ground bar, but the neutral and ground appear to be connected. If the ground also goes to an outside ground rod and the neutral goes back to the electrical company--THEN why doesn't the load simply go into the ground vs. going through the neutral? I've asked 5 people in construction and they have no clue either, just tell me that's the way it works. Does electrical potential has something to do with it?

I also saw a situation where it appeared the neutral and ground were grounded through a water pipe and no neutral was connected to outside power?

If this is not the right forum for this then show me the way out...

Thanks, I just don't know where to go to get the right...

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Please Note: Mark Nicholet is a non-member guest and is in no way affiliated with InterNACHI or its members.


Thank you very much it is clearer to me as well. The resistance in the grounding system to earth makes sense. When the ground and neutral are bonded at the service box there is 3 ways for the current to travel, isn't there?

1. to the transformer (path of least resistance)
2. to the grounding rod etc (to earth, path of most resistance)
3. back to the grounding equipment, creating a circuit and then back to the transformer (metal box, light fixtures, outlet casings etc)

What prevents option 3, the current from going back to the grounding equipment?

Is electricity on a one way street?

What is the difference in bonding the neutral and ground at the service box as opposed to an auxillary panel, isn't it the same?

Hypothetically, I could understand if there was a one way valve in a water system that would prevent...

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