A new update to the National Electrical Code (NEC), widely regarded as the authoritative standard for safe electrical practices, will become effective on February 1, 2023.
The NEC has traditionally defined three classes of electrical power, with each representing a distinct characteristic of a circuit’s voltage threshold. This most recent revision adds a new circuit classification: Class 4 Power, covering fault-managed power systems.
How does this differ from the initial power class categories?
Class 1 power denotes a high voltage circuit with a limit of 600 V of power and requires oversight by certified electricians due to the risk of fire or electrical shock. Class 2 power refers to low voltage circuits of about 24 V, making this class of wiring safe to handle and posing minimal fire hazard. Class 3 power can
Source: Belden Inc. handle up to 300 V and can cause electrical shock but is not a fire hazard due to its additional safeguards.
Class 4 wiring can carry up to 450 V, and with a safety profile resembling Class 2 wiring, it is both safe to handle and poses minimal fire hazard. This unique blend of power and safety is the result of an innovative electrical transmission system, and that’s why it has earned its own classification. These circuits allow industry to support power at higher levels and across longer distances with cables that were previously limited to power levels of 100 W and distances of 100 m while limiting energy and power available during a fault event.
Access this white paper from Belden Inc. to learn more about the new Class 4 category and relevant cable certification requirements.
