Have you ever seen a setup on a machine, typically those manufactured outside of the USA, with two (2) electrical disconnects?
Most of the time, these disconnects are COLOR-CODED to clearly identify their different uses, although we have seen some that were NOT color-coded, nor were they properly labeled! Here is an example of what this may look like; I have highlighted both switches with blue and red boxes…
You may notice that they used the motor disconnect device in this example, and you can also notice that the green “power on” light above it is still illuminated.
As I spoke about in an earlier article this morning, the use of this device may be acceptable based on the SCOPE OF WORK being performed under this LO. But it is CRITICAL that the facility FULLY understand the use of this “motor disconnect” and the difference from using the “Main Disconnect,” as well as which SCOPES OF WORK can be performed under each disconnecting means.
We will not find much help from OSHA on this type of setup, so I turn to one of my favorite RAGAGEPs, NFPA 79: Electrical Standard for Industrial Machinery, specifically Chapter 5 – Incoming Supply Circuit Conductor Terminations and Devices for Disconnecting and Removing Power.
(emphasis by me)