Which voltage band is considered extra low voltage (ELV)?

• A. Band 1: less than 50 V
• B. Band 2: 50 to 1000 V
• C. Band 3: 1000 to 5000 V
• D. Band 0: 0 to 12 V

Answer: (D)

Extra-low voltage is the smallest voltage range used for safety-critical control and signaling because it keeps the shock risk very low. In this set of bands, the ELV range is the 0 to 12-volt band. This keeps the voltage well under the higher thresholds where protective measures become more stringent, so it’s the safest category for low-risk control circuits. The higher bands extend into voltages where insulation, protective devices, and more careful safety practices are required, so they aren’t considered extra-low. That’s why the 0 to 12 V option is the ELV.