You should pay special attention to the way Smart Electrical treats and takes into account certain item types when calculating bus loading.
Three-winding transformers
A bus feeding a two-winding transformer takes into account both the secondary and tertiary connected loads and buses.
Transfer switch (a special PDB with two incomers and one feeder)
Make sure that you connect the incomer circuit that you require.
Equipment connected to an alternative power source
The software treats equipment with two power sources as one load for each of the power paths. See Configuration G.
Bus Drill Down Enabled property
If, in the Properties window, you set this property to False, the software does not roll up any of its connected direct or indirect loads. Instead, the software takes into account the rated and consumed power values that you have entered manually in the Properties window of each respective bus.