Here is a question. You have a 1600 amp service (120/208 volt) in a room with lots of other equipment. Lets say the main service is on the north wall and the only door to the equipment room is on the east wall. (The doors open properly and proper hardware, etc.) The service panel is right up against the north wall (No access panels behind equipment) and there is 3 feet space in front of the service panel. Is one door enough or is 2 doors required? Or can you double the workspace in front of the service equipment and meet code? Or isn't it needed, and 1 door meets code as is?
Sorry this is a Canadian electrical code answer but so many requirements are equivalent between the NEC and CEC. a service over 1200 amps or over 750 volts requires 1.5 meters (5 ft) clearance, or 2 doors if there is only 1 meter (39 inches) clearance if the exit path requires you to cross past the faulted cell. So if the distribution had a fault on the east end of the board where the door is and you were at the west end of the room you would need 5 feet of clearance in front of the board or an exit at the west end of the room in addition to the door at the east side. The 1.5 meters is measures with any draw out equipment in its racked out position. Rule 2-310.
Looking at the commentary and pictures in the handbook, Is the equipment 6 feet wide? if so; I read it that if you can't run straight away from the panel (south door in your case) you either need double working space or 2 doors. The bottom line is, would you be able to get out of there with all your hair if there was fire shooting 3 feet out of that panel. I'm sure your shorts would be a goner in any case
(a) Unobstructed Exit. Where the location permits a continuous and unobstructed way of exit travel, a single entrance to the working space shall be permitted.
(b) Extra Working Space. Where the depth of the working space is twice that required by 110.26(A)(1), a single entrance shall be permitted. It shall be located so that the distance from the equipment to the nearest edge of the entrance is not less than the minimum clear distance specified in Table 110.26(A)(1) for equipment operating at that voltage and in that condition.
With regards to (a): As Greg said...door should be on your 'south' wall.
With regards to (b):
110.26 (A)(1) as long as there is a minimum of 3' from the gear to the nearest edge of the door, it will fly.
So, IMHO, a single egress on the 'south wall' in your scenario would be compliant. And, IF you double to (6'), and maintain a minimum of 3' from the gear to the door edge, that too would be compliant.
BTW, I do everything to avoid one door rooms; being involved in the 'design' stages (as EC) I always squeezed out a large broom closet for my gear. LOL
I can't copy/paste the Handbook pics here, but if you need them, call me and I'll fax it to you.
I thought the "6'wide rule" was removed from the 2003 to the 2005 NEC book. I don't have my books in front of me. I agree with you and John that a door on "south" side of this install would be fine and would meet code. However having the door on the "east" side to me would now require "Double" the work space clearance. I am just wondering if my train of thought was correct.
I have the handbook and I saw the picture, but thanks for the offer.