# Old Service Panel with NO Ground Bar



## PatQuan (May 8, 2014)

I look at a customer's Murray electric service panel. There is only one bar at the right hand side of the service panel where neutral wires are connected, and hot wires are connected to the circuit breakers. There is no bar at the service panel to connect ground wires for each circuit. The entire house has only those groundless "two wire" outlets, and there is no ground wire for switches. 

My customer asks me to install a new circuit. Since all slots are filled with circuit breakers, I want to replace a single circuit breaker with a duplex circuit breaker so that I can install an additional circuit for my customer. 

My question is: Would it be OK if I install a ground bar at the left hand side of the service panel and connect the ground wire to it? That way I can install GFI outlets and regular outlets (instead of those "two wire" outlets) inside the house.

If I cannot install a new ground bar at the service panel, I guess the new circuit would have to be groundless, or I have to replace the old service panel with a new one.

Thanks in advance for any advice you might give me.


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## AllanJ (Nov 24, 2007)

Yes you may install a ground bar.

If the top breaker in your panel is the first master disconnect switch for the house then ground wires (equipment grounding conductors) and neutrals are combined. If you run out of space on the existing bus bar then you may install another bus bar. It is suggested that the neutrals go on the original bus bar where the fat service neutral/ground is attached.

Each neutral wire must have its own hole or screw on the panel bus bar. Two EGCs may share the same hole; this works best when both are the same size.

Be sure to scrape the paint off the back of the panel where you attach the new bus bar and also follow the mounting instructions to assure a good metal to metal contact. The original bus bar also needs (always needed) a jumper or a direct metal to metal contact with the panel box if this is your main disconnect panel. A screw on the neutral bus intended for this purpose that digs into the panel back is also customary. 

If there is a master disconnect switch further upstream, either at the meter or in another panel, then the panel you are working in is a subpanel where EGCs and neutrals must be kept separate The neutral bus bar must be insulated from the panel back using plastic brackets. A screw on the neutral bar that digs into the panel back must be withdrawn. A separate bus bar fastened directly to the panel back and used for EGCs is required.

Ground fault circuit interrupter receptacles may be substituted for other receptacles without the immediate need to upgrade to a grounded circuit cable or string a separate EGC. But ungrounded circuits may not be extended (appended to). Any new circuits must be grounded (using cables with built in EGC).


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## PatQuan (May 8, 2014)

Allan, 

Thank you very much for your input. I really appreciate it. What would you advice if I do an experiment of connecting a new circuit breaker with a 12/2 romex wire to an outlet that is about 5 feet away outside the service panel. Since there is only one bus bar and there are still unused holes, can I connect both the neutral and ground wires to the same bus bar, but at different holes in the bar??? If that is possible, then I do not have to buy a new bus bar and install it which saves me time and money. If the outlet is tested hot with grounding, then I will drill holes at the 2X4 studs inside the house to wire cables to bring up a new circuit.

Thanks again kindly for your professional advice.

Pat


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## rjniles (Feb 5, 2007)

Why are you (obviously not a licensed electrician) doing work that requires a license? There are legal and liability issues in what you are are doing.


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## kbsparky (Sep 11, 2008)

rjniles said:


> Why are you (obviously not a licensed electrician) doing work that requires a license? There are legal and liability issues in what you are are doing.


Not all jurisdictions require a license.


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## rjniles (Feb 5, 2007)

kbsparky said:


> Not all jurisdictions require a license.


Not many that allow you to do it for hire for other than yourself.


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## jbfan (Jul 1, 2004)

kbsparky said:


> Not all jurisdictions require a license.


That may be true, but this is basic electricity, and if he has to ask this question, he should not be working on someone else's house.


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## PatQuan (May 8, 2014)

I only work for family members and close friends. The house I will be working on with an old service panel belongs to my cousin's mother. When my cousin built her new house in 2009, she applied for a homeowner permit. I worked for her as a general contractor. I wired her new house and we passed inspection for all the work I did such as underground plumbing, plumbing and electrical, solid hardwood floor, carpentry etc. etc.


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## eastcoastsparky (Nov 28, 2012)

You wanna cookie or something


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## AllanJ (Nov 24, 2007)

When a branch circuit Romex cable is brought into a typical main panel (with its top breaker as the master building disconnect) the equipment grounding conductor and neutral are put into different holes of a shared neutral/ground bus bar.

It is not unusual for either the neutral or the EGC to be spliced for extra reach (using a wire nut) particularly if the arrangement of wires on the bus bar gets re-arranged. For example the EGC gets moved to a new bus bar on the other side to free up space on the original bus bar for new circuits' neutrals.

A second neutral/ground bus bar may be used for neutrals if it is connected to the first using a method approved for that make and model of panel, for example with a factory supplied metal strip going between the two bus bars. In a few instances a white wire is approved and its size is typically large enough to carry current equal to the sum of the breaker ratings for the branch circuits whose neutrals land on that second bar.

If the second bus bar used for EGCs only cannot be properly bonded with the panel back (I can't think of any reason why), then a bare copper wire of size at least equal to the largest branch circuit EGC on that bus bar may be connected between that bus bar and the original neutral/ground bus bar.


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## PatQuan (May 8, 2014)

Thanks Allan,

You are my hero of the day.

Pat


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