I have an Eaton Cutler-Hammer meter/breaker box. (MB816B200BTS-FLCH) I want to run a 20 amp circuit (underground wire) from this box through existing underground conduit to a receptacle for a dishwasher. This run would be app. 15' to 20' and from my main house panel it would be 40' to 50'. All breakers in this box are doubles at present. Black to one side white to the other side and ground to the bonded neutral bar. Can I use a single pole "BR" type breaker from this box for the 20 amp circuit by hooking black to breaker and neutral & ground to the bonded neutral bar? I want to avoide a sub panel for one circuit if possible.

Can you show a photo of your panel? Not sure what you mean by "doubles".

The wireing diagram can be seen at

http://www.eaton.com/EatonCom/SearchResults/index.htm?ssUserText=mb816b200bts

The 4th item down shows "Native Document" TD00502001E.pdf Page #13 top center diagram is for my panel.

The breakers already in this panel are (2) 125 amp breakers hooked together with a clip that go to the house, (2) 60 amp breakers hooked with a clip that go to the AC, and (2) 20 amp breakers hooked together with a clip that go to the well.

If I count right, and you have three 2 pole breakers as shown in pic, then you used 6 of the 16 available breaker spaces, and you can use 1 pole breakers in the remaining slots.

Thanks, I thought so. How do you wire the 1 pole breakers since there are not separate ground and neutral bars?

In the main panel grounds and neutral occupy the same bar(s).

The only restriction to this is if you add a ground bar by screwing it to the back of the panel it can only serve as a ground bar.