Sizing for AFC and AIC on older unmarked system

[Fred B]

Looking at new installation and renovation on a portion of an existing 800A 3Ph (wye?). No markings on existing 800A service panel to indicate AFC or AIC nor at any of the existing mixture of panels. Most of the smaller existing disconnects have marking of a mixture of 208V and 240V, but nothing on the primary distribution equipment. Many unknowns left from the building owner.

For purpose of the new installations (one entire floor of mfg.) what steps or how do I determine the existing system AFC and then appropriately mark existing and new panels? Most everything in the building is unmarked. Would contacting the POCO help any?
What level of PPE could be expected to be needed in making the connection to the existing distribution panel for the new (renovated) plant section without the information related to AFC? (Probably no way to anticipate with out more info.) This information would also be needed in sizing new equipment and lighting panels for appropriate AIC ratings.
No information on mfg. equipment to be installed yet, other than most are 20A motor operations, but would presume this too would be effected by the total system and might require some fault reduction means if existing system too high.

So where would you start? What would you see as KEY information to ask for in process of developing a bid? Figuring piping and that portion not a problem but its the system requirements that seems to be missing some info to making any reasonable assumptions for equipment. Any assumptions that can be reasonably made? This is probably the biggest project I've been approached to participate in. About 75,000 sq. ft. of mfg. floor area.

 

[Dennis Alwon]

I would probably get info from the power company on the transformer and calculate the aic from there

 

[petersonra]

I think you will need to do some investigating.

As for level of por, the level is none required at all because you will have to arrange for the power to be shut down when you connect. No live work.

 

[Fred B]

I think you will need to do some investigating.

As for level of por, the level is none required at all because you will have to arrange for the power to be shut down when you connect. No live work.

But sometimes even the task of shutting down has a risk level requiring PPE depending on equipment state and AFC. This power equipment existing without marking and old so condition is unknown.

 

[petersonra]

But sometimes even the task of shutting down has a risk level requiring PPE depending on equipment state and AFC. This power equipment existing without marking and old so condition is unknown.

That is the pocos problem to deal with.

 

[Fred B]

That is the pocos problem to deal with.

Not sure how. The service equipment is not being planned to be replaced, but the conditions of the equipment unknown can be a risk even in the shut down process for the service disconnect. We would only be adding into the Distribution panel to send a feeder up to the upper level equipment and lighting panels.