Below are the recommended steps to perform on site to gather existing Electrical system information.
Start from outside.
Look for meter or meters outside.
Sometimes there are more than one.
Sometimes they may be hiding.
From there, determine if the building is fed via underground or overhead. This is important in case the service capacity needs to be increased.
Overhead service is easy to modify with less cost to owner.
Now determine the building electrical characteristics.
Sometimes, if you are lucky, it can be found on the side of a utility transformer.
Now determine the building electrical characteristics. Most of the times, it can be assumed from service disconnect switch nameplate.
All else, it can also be determined from the panels inside.
Now that we know what the building system is, we need to find out the capacity available to the building.
In this case, it’s relatively easy to find out what it might be.
Suite # is labeled on each meter, which is directly connected to each disconnect switch.
However, most of the time, we are not that lucky.
Nameplate will be worn out and not legible, and may need to open the disconnect switch to see what the amp rating of the fuses are.
However, we do not recommend doing this, so Don’t Do It!
We can also estimate the service capacity to each space with the size of conduits to each tenant space or the physical size of the disconnect switches…
Also can be determined from panel or switchboard nameplate.
But the size of the panel or switchboard does not necessarily means the capacity of the building. Good assumption, though.
The best way to find the capacity is to find the main breaker at the main service entrance equipment.
Main Electrical Room
…Other times, you may have to take multiple pictures to get overall picture.
Main Electrical Room
…then take close up shots of each panel including the panel schedule.
Other equipment
Don’t forget about the transformers. On floor and overhead.
Also take close up of the name plate.
Other equipment
Overall Space
Site Notes
