It is one of many manholes on an ethanol project...it will contain Medium voltage cables (4160) fiber and control and DC circuits..the are 8'x 8'x8'. They have a base and a top... the specs call for a 0.3% slope TOWARDS the manhole..
I did not find that requirement anywhere in the code..
It seems they will need racks inside to rack the cables as well..
Check sec. 110 V of the NEC, that talks about manholes and their construction also sec. 490 talks about voltage over 600. You also might have to refer to the National Safety Code. Most utilities follow those rules. I might have an old NESC book around, I would have to look.
"110.70 General. Electrical enclosures intended for personnel entry and specifically fabricated for this purpose shall be of sufficient size to provide safe work space about electrical equipment with live parts that is likely to require examination, adjustment, servicing, or maintenance while energized. Such enclosures shall have sufficient size to permit ready installation or withdrawal of the conductors employed without damage to the conductors or to their insulation. They shall comply with the provisions of this part. Exception: Where electrical enclosures covered by Part V of this article are part of an industrial wiring system operating under conditions of maintenance and supervision that ensure that only qualified persons monitor and supervise the system, they shall be permitted to be designed and installed in accordance with appropriate engineering practice. If required by the authority having jurisdiction, design" (documentation may be required)
Last edited by HotLine1; 06/01/1303:41 PM. Reason: added text in parenthesis