Grounding New 200a Panel

I have a grounding question.  I am installing 400a service to my new home.  We ran 350MCM wire underground thru 3" conduit from the 2ndary terminal (moped) to the house into a 320A Cooper B-Line meter.  From the meter we ran 2 sets of 4/0-4/0-2/0 thru the wall to 2-200a breaker panels ("standard practice", according to my electrical supplier).  The ground wire (#4Cu bare) from the grounding rods comes up from the ground and we're curious if there has to be a special splice connecting the ground wire to each breaker panel or can we run thru one breaker panel to then next, say by connecting the ground wire to a ground bus on one panel and running that thru to the next with #4Cu bare or #6Cu in conductor.  Different electricians are suggesting different methods and the electrical inspector is unsure, but seems to be leaning towards the "special splice". Any feedback would be appreciated.
      

I had posted a week or so ago about random afci's tripping aroung my house that is a year old. I am fairly convinced that it's a interference problem or something in my ground system. Outside my house there is a meter and next to it is a small breaker panel with a 200a breaker that feeds the panel downstairs. Outside there are 2 big black wires going to the ground bus. They go inside and one goes to the water pipe that comes in from outside. O can see where the other one goes. Is it important for me to put in a ground rod and run a big wire to the outside box? My las two new houses had them. I'll try to upload a pic of the outside box. Thanks
      

My new 200a semiflush panel came with an L shaped nailing flange that comes forward out to the face of the panel. (pretty ugly on nice new panel)

Q-Is this "extra" flange designed to be bent back over the nailing flange after mounting and before stucco? maybe to put the flasing in between?

maybe dumb question but i just want it to look right and to do it only once.

Picture of my panel attached
      

I have an older QO-Square D eight circuit panel. It is being used as a subpanel and when installed was not bonded.

The neutral bar consists of a bar mounted with one screw and a second bar mounted to it by standoffs. This second bar is where the bonding screw is. I can see no way to separate these two bars for proper bonding. There is no provision for mounting this second bar.

I wish I could post a picture but I will have to work on that.

I am thinking I will have to purchase a new panel but can't understand why neutral and ground cannot be separated.
      

this topic came up on another thread but its buried pretty deep. it is my understanding from several experienced posters that under normal circumstances all neutral current should flow back to the utility neutral, not the grounded plumbing or rods.



i am trying to figure out why. bear with this simplistic example.



100a service - 3 wires in - A (hot+), B (hot-) and N (neutral).

circuit 1 on A is using 12 amps

circuit 2 on B is using 7 amps

so a total of 5 neutral current amps have to go somewhere.



they could all flow back on N, but if bonded to N at the panel is a low resistence connection to say, copper water pipes, wouldnt some of the current flow there?



is the utility neutral supposed to be so low resistence that none of the current would flow to the grounds? if that is the case i need to call my utility ASAP because a considerable amount of current flows to my main ground.



where i am struggling is i dont see how a utility pole or transformer would be any lower resistance than miles of metal plumbing and since they are bonded together, the current can choose (i know wrong word but im not an electrican or an engineer) either path
      

I'm having quite the time finding an electrician who will quote this.  Just about all of them say that what I need is to upgrade my main panel but I want to install a new main panel that is a part of the meter base outside and make my current 100A panel a sub.   Maybe you people can tell me why nobody seems to want to do this.  Here are a few shots of the existing meter (note what is apparently a 60A base here)






and a shot of the conduit headed underground.  Like most homes built during this era, the conduit makes a right turn underground to enter through the cinderblock, ending up coming into the back of the main panel.  This conduit encloses a 4 wire feed. edit: no, actually it is only a 3 wire feed which is a problem if I want to convert the original main panel a sub.






Here's the existing panel.  It's a 60's era Square-D split panel with a 30 amp sub panel for the finished basement.  Those are low voltage wires to circuit taps for my home energy monitoring system btw.






The reason I don't want to upgrade this panel are as follows:

We won't be expanding the electrical west of this panel any more.  All planned expansion (240v car charger in Garage, planned 3 season room with grid tie Solar on the roof) will be to the east.


Upgrading the panel will require major surgery to the walls.  Due to the way the original basement is engineered there, the walls have an intricate stud pattern behind the existing panel.  I'd pretty much have to rip out a 4' section and redo it to make the access large enough to handle a 200A panel.


Adding additional circuits to an upgraded panel will require an act of God due to the finished basement construction.  There are no raceways for additional circuits.






Based on this, my thoughts were to create a new 200A main panel outside based on something like the GE model TSM420CSCUP loadcenter.  Here's a shot of this panel:






This particular panel has room for three 2-pole breakers in addition to the 200A mains.  I'd add a 100A 2-pole breaker for the existing panel, with the other two reserved for the garage/solar expansions.



The issue with the contractors who have quoted the job appears to be the conduit going to the existing panel.  I'm not sure what's wrong with it but it is apparently not compliant with current code.  Obviously the bonding needs to change, new grounding electrodes need to be driven, and a water pipe ground needs to be established to the new main panel, but what else is required?



I'd like to throughly research all the code considerations here so I can approach a contractor from a more knowledgable perspective then determine the best way to perform this upgrade.  Due to POCO coordination and the need to cut household power for the duration of the job, I have no desire to DIY this one...



So what exactly is wrong with the conduit running from the existing meter base to the existing load center?  Why is everybody telling me that I can't do essentially what I've described above?  What are the relevant code sections that will apply to this job?  Should I be chatting with my AHJ about local considerations now or should I wait until I have the code requirements down pat (assuming the latter here)?
      

I have 3 wire direct bury feeder cable from a 200 amp meter base/sub panel to a 125 amp sub panel on a post 150' away and the 125 amp sub panel will feed a 30 amp RV outlet box.

The 3 wire feed was already there and I know it is not to 2008 code, but my question is: do I need to bond the neutral bar to the ground bar and to a ground rod at the 125 amp subpanel?
      

I have an outdoor light fixture that I am trying to replace.  The house was built ten years ago.



When I removed the original lamp, I noticed one of the two leads was wired to the ground, and one was wired to the black wire, which is hot per my current sensor.  There are three wires in the box - black, ground (bare copper), and white or neutral, all from a single romex cable.  Unfortunately, I do not recall where the white was when I removed the original. 



I wired the new lamp per the instructions, something I have done many times before - black to black, white to white, and bare copper ground to ground.  Nothing.  The lamp and bulbs are brand new, and I have tried four separate bulbs.  I checked the black and neutral with my current sensor and with the switch on and the lamp installed this way, both show as hot. With the lamp not installed, the switch on, and the wires disconnected only the black shows as hot.  The switch is single pole, and appears to be wired correctly with a black to each screw on one side and a copper ground on the other.



Assuming the new fixture was bad, I reinstalled the old fixture correctly -  black to black, white to white, and bare copper ground to ground.  Still nothing. No light, and I confirmed the bulb is good by putting it in another lamp.   The only way to get it to light is to connect the neutral in the lamp to the bare copper ground.



I capped the wires, turned the circuit back on, and identified all the outlets, switches and fixtures on the same circuit.  I opened every one of them up (four lights and eight outlets) and found three (one switch and two fixtures in another room) where multiple commons connect.  All were properly connected.  My outlet tester shows all outlets as "correct".  I found no instances of grounds connected to commons or vice-versa.



Any ideas?  Is it proper to wire this thing the way I found it?



Thanks for any and all advice!
      

Installing a 4-ton condensing unit outside (240V, 1 ph, MCA= 26A, MOP= 45A).  There will be a HVACR rated 45A breaker at the panel.  Plan to install the 60A non-fused disconnect with GFCI recepticle (GE U065NA1010) next to condensing unit.  Plan to use #8 wire since distance from panel is 80 feet, but unsure of the number of wires.  How many conductors will be required since the disconnect will have a 120V GFCI recepticle.  Will I need 2 wires (2 hots and 1 ground) or 3 wires (2 hots, 1 neutral, 1 ground)?  I'm thinking #8 wire with 3 conductors (2 hots, 1 neutral, 1 ground).
      

Need a little advice... Here's the scenario:



-200 amp meter/main.

-2 small side by side residences with 80 amp load each.

-Each residence has a 200 amp panel with main disconnect.

-1 3" conduit from meter to underground pull box between both buildings

-A 2" conduit from the pull box to each building.

-All conductors to be 3/0



Is there any reason why a 3/0 feeder with ground could not be pulled to the

pull box and then split to run to each building instead of running 2 separate 100 amp feeders? Any other things to consider?