“Draw a 480 V utility and 500 kW emergency generator feeding an 800 A automatic transfer switch, a critical-load bus, and two 200 A feeder breakers serving 100 A critical loads.”
Read the decisions behind it.
The 480 V utility and 500 kW emergency generator are the two inputs to ATS-1.
The 800 A ATS selects the source feeding the critical-load bus.
The ATS output feeds one labeled 480 V critical-load bus.
Two 200 A breakers leave the bus for separately labeled 100 A critical loads.
Use this as a compact backup-power topology for a facility with generator-supported critical loads. Perform load, fault-duty, protection, fuel-runtime, and code compliance studies for the actual project.
Other examples in this family.
Common questions
What does the ATS do?
The automatic transfer switch selects utility or generator power for the critical-load bus according to its control logic.
Can a 500 kW generator supply an 800 A ATS?
The ATS may be rated above the generator output. Verify the generator current, load demand, and fault ratings rather than comparing ratings alone.
Why are the critical loads behind 200 A breakers?
Separate breakers provide branch protection and isolation for each feeder from the common critical-load bus.
Does this show generator grounding?
No. Grounding and neutral switching depend on the system arrangement and require a project-specific design.