Existing infrastructure design approach

[lmichael310]

I am involved in a electrical design that consists of relocating existing electrical conduits/wire and replacing a set of existing tunnel lights. The issue is that there are few if any as-built drawings available and there is a need to replace the tunnel lights and add additional lights to meet the customer lighting standards. In this case, the problem will be able to be solved because the existing lamps will be replaced with leds and the subpanel is labeled feeding the tunnel lights. However, this made me think what would be the best approach if I was presented with a similar scenario. From your experience, what is a good overall design approach when adding to an existing electrical infrastructure but there is a lack of as-builts and other necessary plans/doc to determine conduit routing, conduit sizes/wire and existing panel loads?

 

[dicklaxt]

I have been involved in exactly that same scenario.There is only one way to skin that rabbit and that is to go to the site,get an electrician,the two of you walk it down,open fittings boxes etc,note location of all users.You must be taking notes ,making sketches etc along the way.You then take all of this info and prepare a set of as built dwgs,you will more than likely nedd a couple of more info gathering walk thrus to finalize the as built package.Now get the owner/client to sign off on these documents.The is the end of Phase 1 and Phase 2 can begin,where you then make demolition drawings this is the end of Phase 2,,,,,,Phase 3 would then be on the design table adding in any and all changes as well as any new equipment.

A thing to be asked up front,,,,, is this area to remain energized during the walk throughs and demolition,,if so the Phase's would need to be restructured as to what comes first in all aspects and when certain cut overs can be acomplished.

The larger the project ,naturally the more care and documentation needs to be set forth.

Hope this helps a little.

dick