Learn to read the connections.
Explore a single-line power path, measurement and protection signals, and earthing connections. Click equipment to find out what it does, how to recognize its role, and what the drawing cannot tell you.
Educational reference only. Examples and calculator results are not approved installation designs, equipment selections or operating instructions.
LESSON 1 OF 3
Read a single-line power path
Click a supply, breakers, transformer, busbar and load to trace a simplified three-phase single-line diagram.
Explore the diagram LESSON 2 OF 3Read measurement and protection paths
Learn how CTs and PTs/VTs supply measurements to a relay, and how a trip command differs from the primary power path.
Explore the diagram LESSON 3 OF 3Read earthing and bonding connections
Identify exposed metalwork, protective conductors, the main earthing terminal and an earth electrode without confusing PE with neutral.
Explore the diagram