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Subject - nuetral/ground bus bar
r1racer One of my subpanels seems to have either no ground or nuetral bus bar as both grounding and nuetral wires are connected to this one bus bar. is this common or is my subpanel required to have both bus bars? If so, would i have to get a new sub or add a new bus bar?
Ryan_J Is this the panel that contains the service disconnect?
r1racer No service disconnect.
kbsparky Subpanels are required to have neutrals isolated from the grounds. Sometimes, I will encounter a boot-legged job (usually a Harry-Homeowner DIY install) where they used a service panel as a sub-panel, and did not install ground bars for the ground wires.

Usually, when we encounter such jobs, we will install a ground bar kit, and pull all those grounds off the neutral. We also eliminate that bonding jumper or screw as well. Of course, this all assumes that there was the proper 4-wire subfeed cable or conduit installed in the first place
r1racer The proper feed cable was installed, 4 wire (white to nuetral bus bar, black & red to hot bars, but ground also to nuetral bus bar), correct gauge.

I called an electrician today to get an estimate on how much it might cost to come in and do a thorough inspection of my panels and add some circuits in my basement.

I also told him that I only had one bus bar in my subpanel and asked him if my subpanel needed a separate (unbonded to nuetral) grounding bus bar and he said no! He said it is ok to have ground wires and and nuetral wires on the same bus bar in both subpanels and a main panel.

So, you guys say they need to be separate, as did a book i read, meanwhile this guy says they dont. Whats the theory behind separating the nuetral and ground wires in a subpanel but not in a main panel that contains the service disconnect?

Thanks.
Electricman r1racer, the reason is to eliminate a parallel path for the neutral current. I hate to say it but your guys wrong, call another electrician and get the job done right for your safety and your familys. kbsparky, (Harry-Homeowner DIY install) That theres funny
kbsparky >>... He said it is ok to have ground wires and and nuetral wires on the same bus bar in both subpanels and a main panel...<<

You need to find another electrician. One that understands the proper bonding and grounding of panels, sub-panels, and circuits.


>>...Whats the theory behind separating the nuetral and ground wires in a subpanel but not in a main panel that contains the service disconnect?<<

First, you have to understand that the neutral is a current-carrying conductor, whereas the ground wire is not. As such, the neutral wires are insulated, the same as any other current-carrying conductor. The misunderstanding comes from the fact that the neutral wire is intentionally grounded at the main service panel only. The reason for this action is to allow ground-faults (or "short circuits" to ground) a return path back to the source of power, the utility transformer. Having the ground wires bonded to the neutral makes it possible for the circuit breaker to trip out easily under such conditions.

IF one were to connect the current-carrying neutral wire to the ground wires "downstream" then it's possible for some of that current to follow what is called a parallel path -- over the bare grounding wires -- instead of the insulated neutral wires -- as it finds its way back to the source.

Keep in mind that the metal outside frames of your utilization equipment --> appliances, furnaces, water heaters, etc. are connected to that bare ground wire, and you absolutely do not want those metal frames to be carrying any of that current in their normal course of operation. Such stray currents can have potential differences between them and a grounded surface, such as a concrete floor, or the frame of a different appliance connected to another circuit. Potential difference = Voltage.

And Voltage can = shocks.

-Ken
kbsparky >>... kbsparky, (Harry-Homeowner DIY install) That theres funny...

Teehee .... I purposely used that term to bring home the fact that many DIY jobs are not up to par (or CODE for that matter), simply due to the fact that "Harry Homeowner" is basically ignorant of many issues. While they may be able to install an outlet, light, or even a paddle fan, when they attempt something like sub-panels, with its more complex rules of such things like proper grounding and bonding as discussed in this thread, they usually fall short.

FWIW, "Harry" and "Harriet" Homeowner were trademarks used by a now-defunct home center store chain called Hechingers.

-Ken
stedder The idea / rule of seperation of grounded and grounding conductors at subs is so basic I'm not sure the "electrician" that told you that it's ok to have them on the same bar in the subpanel is an electrician at all. Like KBS said, you will very possibly have potential current flow on equipment frames of things you don't want and aren't meant to have flow on.
r1racer Ok, I called three more electricians this morning and this time all three said what you guys are saying. I have one scheduled to come out next week and fix the problem. Thanks guys!
r1racer So the electrician came in today and put in a bus bar. It only took him about 10 minutes. He simply screwed the thing into the back of the subpanel (one screw only) and pulled all the ground wires off of the nuetral bar.

So while he was there i asked him to just look around to see if he saw any problems in the wiring in my basement. He found:

1. 12 gauge and 14 gauge wire being used together on a 20 amp circuit
2. 4 of my outlets were in metal boxes that were to small
3. 2 of my outlets had no grunding screws and were not even connected to any wire nuts
4. Too many devices (7 more than code) were placed on one circuit
5. 4 electrical boxes had no covers
6. Wires stapled to the bottom of my ceiling joists

He fixed everything accept the 14 gauge wire on the 20 amp circuit and the wires stapled to the bottoms of my joists.
He told me it would cost $1100.00 to get the correct guage wire on the circuit but said that I really shuldnt worry about replacing the 14 gauge wire. What do you guys think???
stedder I think change the 20 amp breaker to a 15 amp and mark it as such so nobody changes it back, if it dosen't give you any problems don't spend the money.
kbsparky
quote:
4. Too many devices (7 more than code) were placed on one circuit


Must be a local requirement. In dwelling units, there is no limitation on the number of outlets that can be on a circuit. Did he offer any more details of this "violation" and what was the remedy
r1racer
quote:
Originally posted by kbsparky

quote:
4. Too many devices (7 more than code) were placed on one circuit


Must be a local requirement. In dwelling units, there is no limitation on the number of outlets that can be on a circuit. Did he offer any more details of this "violation" and what was the remedy


NOPE.
BASE I think this GUY is full of SHIIIIIIg. Bless your soul for having to pay this. As far as the 12 and 14 gauge wire on the same circuit goes, put it on a 15 amp breaker to eliminate any confusion. But to charge you $1100 to change that and to """CORRECT"" the stapling of the wire on the ceiling joists????? Help us all.... Where are your ceiling joist?? And why is this a problem??
hanz147 In response to the issue of too many devices per branch circuit.I assume from the information this was in a residential application.
I think there is some confusion on this.I am looking at the 2005 NEC.
220.14(I) Receptacle outlets- "Except as covered in 220.14 (J) and (K),receptacle outlets shall be calculated at not less than 180va for each single or for each multiple recptacle on one yoke"
If you look at 220.14(J) that addresses dwelling occupancies.I would interpret this to mean that the 180va/yoke does not apply to most dwelling receptacle outlet branch circuits.So,in other than dwelling units there are restictions on number of devices per branch circuit.
180va/device see 210.24 TABLE,210.21 TABLE.Take a look at this and see if you come to the same conclusion.If I'm wrong please correct me
kbsparky
quote:
...in other than dwelling units there are restictions on number of devices per branch circuit.
180va/device see 210.24 TABLE,210.21 TABLE.Take a look at this and see if you come to the same conclusion.If I'm wrong please correct me...


You are correct. Since this discussion involved a dwelling unit, the statements made here about unlimited outlets on a circuit are valid.

In other occupancies, there are indeed limitations as to the number of outlets allowable, with 180 VA being the standard load used when calculating the total per circuit.
blackrd Skills vary among individuals, (especially unqualified ones). This is apparent from you getting two diffrent (and wrong) explanations for two diffrent situations in this dwelling. The two things these electricians were wrong about is so basic to the residential electrician that it makes me worry where you got these two guys from. Always ask for references, insurance info(my state farm guy can fax it right to your house for free),etc,etc,etc. Dont trust your familys lives to unqualified nitwits masquerading as electricians.
stedder Ken even though the 180 va rating is for other than, I try to limit my circuts to these numbers for good practice, I know it costs more but I feel it's worth it, although sometimes it can't be avoided.
greenelectric racer,
You and your family are in great luck by having the grounding (bare or green)conductor and grounded (white or with white stripes) in the same bus bar and never being shocked either by a cover plate screw, or by any applicance, or any outer conductive way.