The primary voltage of distribution transformers is typically what value?

The primary voltage of distribution transformers is typically what value?

• A. 4.8 kV
• B. 480 V
• C. 12 kV
• D. 34.5 kV

Answer: (A)

The primary on a distribution transformer is the voltage fed from the distribution feeder. In many urban distribution systems, that feeder voltage is around a few thousand volts, with 4.8 kV being a common level. The transformer then steps this down to the lower voltages used by customers (such as 120/240 V or 480 V, depending on the design). The other options represent either the low-voltage output (480 V) or voltages used in different parts of the system (12 kV or 34.5 kV) and aren’t the typical primary for a standard distribution transformer in this context.

The primary on a distribution transformer is the voltage fed from the distribution feeder. In many urban distribution systems, that feeder voltage is around a few thousand volts, with 4.8 kV being a common level. The transformer then steps this down to the lower voltages used by customers (such as 120/240 V or 480 V, depending on the design). The other options represent either the low-voltage output (480 V) or voltages used in different parts of the system (12 kV or 34.5 kV) and aren’t the typical primary for a standard distribution transformer in this context.