I am getting some conflicting info and would like some clarification. Here is the setup...I have overhead service coming down the pole to the meter, below the meter is a 200 amp fused disconnect. From the disconnect the 3 wires (two hot and one nuetral) go into rigid conduit underground approximately 50ft to my garage (which is attached to the house) where they go to a FP panel. I am having the panel changed out with a square d 200 amp with a main disconnect. My question is can the nuetral and ground be bonded at this panel, that is how it currently is and has been since construction. Bonding at the disconnect will be very prohibitive to run another wire and I would rather not have to go that route. Also should I put a ground rod at this new panel, there currently is none?
Yes, you have to bond the neutral and ground together in the garage panel since you do not have a fourth wire running from the pole. Also, you have to install 1 or 2 ground rods at the garage. Bond to the water as well if applicable.
I am not sure of the integrity of the conduit from the fuses main to the panel in the garage. It is aluminum in construction. How can I check the integrity without digging it up? The current 1960 era FP panel in the garage has the nuetrals and grounds terminated on the same bar (there is only one). At the main fused disconnect below the meter, I see a bare ground wire on the same lug as the nuetral feeder but it has been cut for some reason. Two different electricians have given two different fixes. From what I have read I am assuming it is acceptable to drive a ground rod at the main disconnect and reattach to the nuetral lug with the nuetral feeder wire. At the breaker panel (with a main disconnect as well), I have gathered that I can drive ground rods and connect to the ground bar and leave the nuetral and ground bond there. Does this sound correct? What would be the problems with doing it this way even if the aluminum conduit was continuous?
Without seeing this, it is impossible to properly answer. Of the 2 electricians you have quotes from, 1 may be giving you the correct answer, while the other is giving you the easy answer. Or 1 may be giving you the correct answer and the other giving you a method that will make them more money.
That said, get another quote or 2. Or ask the local building department's electrical inspector for what he wants to see upon inspection, you might even pay for a pre-inspection.
One is says pull another wire for ground and unbond nuetral and ground at the panel. The other says leave it like it is. I just want it the safe way. No permit and no inspection required where this is located.
Want to know the RIGHT way? Since the continuity of the conduit is questionable I would pull a ground wire. This assumes that you CAN pull another wire through that pipe. One reason for not being able to is because the conduit has corroded. Expect this after 40+ years in the ground. I would replace it along with the 40 year old junk out on the pole.
Either way, the neutral should (and should have) been bonded at the disconnect with the panel in the garage being a sub panel. There should be a separate neutral and ground bars.
One thing I forgot to add and I don't know if it makes a difference or not....The main fused disconnect outside also controls the barn as well. I am not sure if this has anything to do with the location of nuetral bonding or not?