What is the standard secondary voltage?

What is the standard secondary voltage?

• A. 4 kV
• B. 13 kV
• C. 120/208 volts
• D. 33 kV

Answer: (C)

Secondary voltage is the low-voltage side of the distribution transformer—the voltage that actually feeds customers. In many urban commercial and light industrial systems, the common three-phase secondary is 120/208 V: each phase to neutral is 120 V, and any two phases are 208 V apart. This arrangement supports standard lighting and outlets (120 V) while also powering three-phase equipment (208 V line-to-line). The other voltages listed (4 kV, 13 kV, 33 kV) are typical primary distribution voltages used before stepping down, not what customers receive on the secondary. So the standard secondary voltage is 120/208 volts.

Secondary voltage is the low-voltage side of the distribution transformer—the voltage that actually feeds customers. In many urban commercial and light industrial systems, the common three-phase secondary is 120/208 V: each phase to neutral is 120 V, and any two phases are 208 V apart. This arrangement supports standard lighting and outlets (120 V) while also powering three-phase equipment (208 V line-to-line). The other voltages listed (4 kV, 13 kV, 33 kV) are typical primary distribution voltages used before stepping down, not what customers receive on the secondary. So the standard secondary voltage is 120/208 volts.