Grounding for two service entrances to same house.
What you have now is no overcurrent protection at the pole, Junk went over this, you have unfused service conductors to the panels on the dwelling and other buildings. Except for the 200 amp panel it is not considered a service disconnect. Those panels enclose the service equipment as the main breakers are the service disconnects at each of your buildings. If you had feeders to the dwelling and other buildings you would have service disconnects/overcurennt protection for each building and your dwelling located out at the pole (grouped disconnects).
The 200 amp panel I understood to be dedicated for electric heat, so I'm picturing a panel with breaker(s) for only the electric furnace when you were using it. It does not have breakers for anything else other than a main breaker? The ahj will allow a feed to a special machine or appliance such as the heater for your home from the pole. It could be that the absence of a grounding conductor is due to the use of metal conduit or metal flex to the heater from the panel. In which case they are using it for the equipment ground. My best guess is that the inspector allowed the unlimited tap rule to power this panel and electric furnace by connecting at the meter can lugs.
In order for the feeds from the yard pole to be classified as feeders they would need to originate from service disconnects used as the overcurrent protection. In which case you would have service entrance feeder conductors not unfused service conductors. In other words feeders are load side of the service disconnecting means.
Now as to the question of 2 services. You only have one service at this point. However if you convert the 200 amp panel to serve branch circuits for your addition you now have a panel that is not special in its application but is in common with the same use as the 100 amp panel. This makes for two sets of service conductors to the house for the same common purpose and is not allowed because the conductors are not service entrance feeders. If you had two service disconnects at the pole and feeders ran to each panel then I believe it would be allowed as I see things from here. Farm yard poles are kind of a different duck than most so you best check again with the inspector. In general if the meter is located on the dwelling and the service disconnect is also located there you can have two feeders to different panels with 400 amp services. From outside points...ie..a power pedestal or something similar like you see for mobile homes you can only have one feeder to the dwelling...period. So I'm not 100% sure about two feeders from the farm pole even if the meter and service disconnect is located there. I'm having no luck finding substantiation in the code book. But from experience I'm pretty sure that with farm poles classiedfied as distribution points under Art.547 it will be allowed to run two feeders. But I sure can't find it in the book.
You will have to clarify with your ahj or inspector. Sounds like they have given there blessing but I cannot see how they are allowing another service panel on the same dwelling when it is not fed from a service disconnect. Again maybe somehow they are using the unlimited tap rule from the farm pole.
The disconnect at the pole is not a service disconnect it is there for maintenance, and emergency purposes and usually provides for a means to connect standby power in the event of a long power outage.
And yes you have a 400 amp service with 320 continuous amp rating as evidenced by the CT monitoring at the pole.
Last edited by Stubbie; 09-23-2008 at 11:03 PM.