How long should a capacitor bleed down to a safe voltage after being taken offline?

The safe voltage bleed-down time for a capacitor is generally around 5 minutes. This duration is based on standard safety protocols to ensure that any residual voltage within the capacitor has dissipated to a level that poses no risk of electric shock or equipment damage. Capacitors store electrical energy, and if not allowed adequate time to discharge, they can remain dangerous even after being disconnected from the circuit.

During the bleed-down period, the capacitor releases its stored energy through a resistor or a load, gradually reducing the voltage to a safe level. This safety measure mitigates the hazards associated with working on electrical equipment and ensures that linemen are not exposed to potentially lethal voltages.

While other time frames may seem adequate, they do not align with industry best practices for safely discharging capacitors, which emphasize the significance of allowing sufficient time to eliminate risks associated with stored energy. Hence, 5 minutes serves as a standard guideline for ensuring safety.