200 amp panel with 1/0 wire

Is it acceptable to have 1/0 wire SE on a 200 amp entry breaker?

So Peter, are you saying that between the meter and the Main Disconnect you have 1/0? If so, that would be too small (2/0 Copper or 4/0 Aluminum----typically). Some times I see this where you have a 200 amp panel with a 200 amp disconnect but it is a Remote Distribution Panel with the “proper” size disconnect located at the Meter.

Yes, That is my question, and I see it on home that were built in the 1990s.

I never see it after 2000.

In my area the nuetral can still be a 1/0. Did you check all the wires or just one?

I checked all to be sure


I thought it might be useful to plop down a copy of Table 310.15(B)(6) from the NEC. This is the table that lists what gauge of conductor of copper and aluminium corresponds with what size residential service. Maybe you already have this stuff, but here it goes anyhow:

In the instance of this thread, if you see a 1/0 copper terminated on a service overcurrent protection device greater than 175 amps, you have a problem on your hands.

If that 1/0 copper has some other protective device at it’s starting end, rated 175 amps or less, then it’s okay. In that case, the 200 amp breaker would be nothing more than a disconnect that also happens to be a 200 amp breaker.

even better answer…can 1/0 be for 200A…simple answer is NO…because if it is SE ( not SER ) it would not have a disconnect ahead of it…unless they just SCREWED it all up…:slight_smile:

SE is the general class of cable, which includes many cable types such as SEU, SER, and SEA.

Yeah but I think he is talking about simple SE…(3 conductors ) and not 4 as in remote distribution panel…could be wrong however

In my area home inspectors have no business checking the size of wire.
This is beyond the scope of a home inspector .
I wonder why a home inspector would even be probing in a section of the service to look at the cables .
This service was originally inspected and passed for usage.
Really why should I be doughting the original installation.
Where does this stop .
I do a visual inspection of all ready accesssable parts of the home .
The same I do not take an air conditioner apart to see if the AC mechanic has installed it correctly example did he use the correct solder lead or silver.
The same I do not check to see if the plumber used lead solder or lead free solder.
As a home Inspector I feel this is not my job and I do not check the size of feeders in a service.
Roy Cooke

You’re joking right?

Are you telling us that you do not move the panel cover to;

  1. look at the circuit breakers and wiring to see **what kind of condition **
    ** they **are in?
  2. To see if they are any double tapps?
  3. To see if a smaller gauge wire is inserted into a larger sized circuit
  4. To see if they has been any arcing?
  5. To see if there has been any water seepage into the panel box?

I could go on and on, the list is endless!

I hope I have misread your statements and or miss understood your meaning!

Please read what I said unless our main panels are different then ours
the main breaker is still covered when the the lower section is opened .
No where did I talk about Double taps ,circuit breakers,smaller gauge wire,or water seepage …
I was talking about the main feed and nothing else.
I again reiterate I do not think many if any home inspectors should be going into see what size the main feeds are.
I hope you have been reading some of the electrical questions on this BB and you have seen how little knowledge many home inspectors have on electricity.
I do think I have a reasonable electrical knowledge maybe more then you .
No I was not joking not a little bit.
Those in power in Canada are trying to stop HIs from even looking in the lower section of the panel.
Do you yourself really think all Home inspectors are qualified to throughly inspect the main electrical panel???

Roy Cooke

The only reason I questioned the 1/0 was becasue on one inspection that I pointed this out their electrician said it was OK to go one size breaker larger than the rating of the wire.

So I wondered if anyone on NACHI had heard such a thing but based on the answers they have not.

2.7. Electrical
I. The inspector shall inspect:
[INDENT]A.** The service line**.
B. The meter box.
C. The main disconnect.
D. And determine the rating of the service amperage.
E. Panels, breakers and fuses.
F. The service grounding and bonding.
H. A representative sampling of switches, receptacles, light fixtures, AFCI receptacles
I. And test all GFCI receptacles and GFCI circuit breakers observed and deemed to be GFCI’s during the inspection.
I. And report the presence of solid conductor aluminum branch circuit wiring if readily visible.
J. And report on any GFCI-tested receptacles in which power is not present, polarity is incorrect, the receptacle is not grounded, is not secured to the wall, the cover is not in place, the ground fault circuit interrupter devices are not properly installed or do not operate properly, or evidence of arcing or excessive heat is present.
K. The service entrance conductors and the condition of their sheathing.
L. The ground fault circuit interrupters observed and deemed to be GFCI’s during the inspection with a GFCI tester.
M. And describe the amperage rating of the service.
N. And report the absence of smoke detectors.
O. Service entrance cables and report as in need of repair deficiencies in the integrity of the insulation, drip loop, or separation of conductors at weatherheads and clearances.

Roy, while the guy has a specific question on the rating I think it is VERY much an issue where they DO have to comment on the size of the service conductors…How would they comply to the SOP at the least if they did not forumulate the size of this service based on the important factors…Panel Rating, Conductor Size and OCPD size…and using them to define the service size…ignoring the size of the SE conductors would be simply put…wrong.

I guess that is just another example of the differences between our two countries .
Thanks Roy Cooke

Never read that in the codes. (about the using a breaker size one larger tan the rating of the wire) I think your electrician was misinformed.

I was surprised to find out that in Canada the HI’s don’t inspect the electrical panel with the deadfront cover removed.
Here I find so many home owner produced safety hazards inside panels that it is unreal. Especially when it comes to home owner installed distribution panels. If I were a home buyer I would want to know if these conditions existed in the home I am about to purchase and move my family into.
Just the day before yesterday I found where a homeowner wanted some more space in a panel for outlets in a garage. The owner removed the 10-2 cable from a 30 amp breaker and double tapped it to a 50 amp breaker, and then proceeded to install the garage outlets (14-2 cable) two circuits, on the 30 amp breaker. Might as well have just double tapped everything at the SEC lugs…it is just about the same result. :slight_smile:

Strange because I thought all NACHI members had to follow the SOP atleast to the minimum of the standard.

I just happen to find it very important that if an HI is going to comply with the SOP that they need to understand that the Conductors must be sized properly for the service in question. The OCPD’s should not be oversized for the conductors to which it is protecting and so on.

I did not know that concept was different in Canada…I** think quite possibly that Nick and Deanna ( if they are reading this ) should consider dropping me from the speaking list in Canada…I most certainly do not mind not going…**

I will preach this day in and day out…so if this is not the case in Canada I think people will be wasting their time listening to me at the convention and I have better things to do with my time…

We also still manfacture Stablok panels and a large % of new homes have them installed .
Yes My home has A Stablok service
Roy Cooke

Actually if they could keep the homeowners out of the panels, there would be a lot less for us to report on. :slight_smile:
BTW the way I don’t think anyone is concerned with the newer Stay-Loks, just the old ones.

We have 93 members in our state chapter. I don’t know about “all” home inspectors but I do know that our chapter members are certainly qualified.
We are “top-heavy” with engineers, electricians, certified HVAC technicians, certified plumbers, past and present code officials, etc., etc…
We provide three hours of continuing education on different subject matter each and every month. One of our members taught Home Inspection classes at the local community college.
We have a very highly trained and educated group of people.

*]I don’t think we are different from any other chapter.