How long should I wait before touching internal components after powering down the PipeWorx 400?

A dangerous DC voltage remains in the capacitors after power is cut. Always wait at least 5 minutes after disconnecting input power before touching any internal components, OR measure the input capacitor voltage and confirm it is near 0V before proceeding. The capacitor voltage measurement procedure is described in Sections 7-6 and 7-7. (Page 13)