AutoCAD® MEP 2009: Creating and Linking to
the Electrical Project Database
One of the most exciting enhancements
of ACAD MEP 2009 for electrical engineers is the electrical
project database (EPD) which is now an external file. This
allows you to manage your circuits and loads as you create
and modify your circuited systems throughout all of your
project drawings (dwgs).
Panels, circuits, devices and wires that make up electrical
systems reside in multiple dwgs which are now linked to the
EPD. This keeps track and ensures the accuracy of devices
and loads in all project dwgs, even if devices in multiple
dwgs are assigned to the same circuit.
To Create an EPD:
Electrical menu > Electrical Settings > Electrical
Preferences
On the Electrical Preferences dialog, click the Electrical
Project Database tab (shown below)

Next, click on the NEW button, browse to a location for the
EPD to reside and enter a filename, then click Save (shown
below)

Once created, you can now link project dwgs to your EPD. To
link a dwg, while open, go back to the Electrical Project
Database tab of the Electrical Preferences and click the
Open button. Navigate to the location of the newly created .epd
file, select the file and click Open.

You must link all of your electrical project drawings to the
same project database. You can link a dwg to only one EPD at
a time. NOTE: When linking, you have the option to choose a
Fixed or a Relative path reference. I recommend the Relative
path as this reduces the risk of breaking the link between
the dwg and EPD.

The drawing status bar shown above indicates no EPD has been
linked to the current drawing. The status bar shown below,
with the addition of the blue and red icon, represents a dwg
with a linked EPD.

Reloading:
If two or more people are working on linked dwgs
simultaneously, you can reload the latest data from the EPD
into your active drawing to ensure that you have the current
circuit information. Or if you have two or more linked
drawings open, and you save changes to one, you can then
reload the data into the other dwgs linked to the EPD. As
soon as a linked dwg is saved, the EPD status icon indicates
that the database needs to be reloaded as shown below (the
icon has a warning symbol on it with a balloon
notification). Simply click on the blue hyperlink and the
database is reloaded. The status icon then returns to
normal.

If other linked dwgs are not open upon saving changes to one
dwg, you will see the below message, you do not need to
reload. Simply opening the dwgs listed will automatically
reload the EPD.

The database is also reloaded every 5 minutes to ensure
accuracy. If you know a change has been made by another
user, you can manually reload the EPD by right clicking on
the status icon and choosing Reload Electrical Project
Database (shown below).

If the EPD can not find one or more dwgs linked, the Reload
Electrical Project Database dialog prompts you, giving you
the option to remove the missing drawing data from the EPD.
(shown below).

If you do not want to use the dwg in the EPD, click on the
check box above to remove its data from the database.
If you want to keep the dwg data, uncheck the box above,
relocate the file and reconfigure the related EPD to the dwg.
This will sometimes happen if the dwg is on a server that is
temporarily unavailable or if someone moved the dwg.
Unlinking: To unlink a dwg from the EPD
You can remove a linked dwg from the EPD, first, remove all
circuited data from the dwg, then save the dwg. Upon saving,
the data from that dwg is automatically removed from the EPD.
Then - Electrical menu > Electrical Settings > Electrical
Preferences
On the Electrical Preferences dialog, click the Electrical
Project Database > select <None> from the drop down list >
Click OK > Save the dwg.
Using the external EPD allows engineers to create panel to
panel connections across multiple drawings; this allows
designers and engineers to utilize the schedules and reports
in MEP to calculate live total build loads with 100 percent
accuracy.