Capacitor Discharge Time Requirements

July 31, 2014
Article 460 covers the installation of capacitors on electrical circuits.

The residual voltage of a capacitor, rated not over 600V, shall be reduced to 50V or less within _____ after the capacitor is disconnected from the source of supply.

a) 15 seconds
b) 45 seconds
c) 1 minute
d) 2 minutes

See answer and applicable Code reference

The correct answer is: c) 1 minute

Article 460 covers the installation of capacitors on electrical circuits. As noted in Sec. 460.6, "Capacitors shall be provided with a means of discharging stored energy. In addition, as per 460.6(A), "The residual voltage of a capacitor shall be reduced to 50V, nominal, or less within 1 minute after the capacitor is disconnected from the source of supply."

Voice your opinion!

To join the conversation, and become an exclusive member of EC&M, create an account today!

Sponsored Recommendations

Electrical Conduit Comparison Chart

CHAMPION FIBERGLASS electrical conduit is a lightweight, durable option that provides lasting savings when compared to other materials. Compare electrical conduit types including...

Don't Let Burn-Through Threaten Another Data Center or Utility Project

Get the No Burn-Through Elbow eGuide to learn many reasons why Champion Fiberglass elbows will enhance your data center and utility projects today.

Considerations for Direct Burial Conduit

Installation type plays a key role in the type of conduit selected for electrical systems in industrial construction projects. Above ground, below ground, direct buried, encased...

How to Calculate Labor Costs

Most important to accurately estimating labor costs is knowing the approximate hours required for project completion. Learn how to calculate electrical labor cost.