I learned about the 90 day rule the hard way… from an OSHA CSHO during a VPP Inspection. I had personally signed off on a very large “temporary project” that installed some field monitors for an environmental permitting project. The MOC made it very clear that these devices would be in place for one (1) full year. I was not smart enough this early in my career to ask about a power source for all these devices.
The MOC did ask about electrical classification, but since all these devices were being installed in non-classified electrical areas the section was checked-off as N/A.
Several months, over 3 months and this is key to the lesson learned, we had our VPP inspection to attempt to get STAR. One of our 90-day items was related to the use of “temporary electrical power” to these devices.
Here is what OSHA (federal) states about “temporary wiring”…
1910.305(a)(2) Temporary wiring. Except as specifically modified in this paragraph, all other requirements of this subpart for permanent wiring shall also apply to temporary wiring installations.
1910.305(a)(2)(i) Temporary electrical power and lighting installations of 600 volts, nominal, or less may be used only as follows:
1910.305(a)(2)(i)(A) During and for remodeling, maintenance, or repair of buildings, structures, or equipment, and similar activities;
1910.305(a)(2)(i)(B) For a period not to exceed 90 days for Christmas decorative lighting, carnivals, and similar purposes; or
1910.305(a)(2)(i)(C) For experimental or development work, and during emergencies.
1910.305(a)(2)(ii) Temporary wiring shall be removed immediately upon completion of the project or purpose for which the wiring was installed.
Bottom line on this… an extension cord is designed and permitted as a form of “temporary wiring”, but when we know we will exceed the 90-day window, extension cords are NOT permitted beyond this time period. If we know, as we did in this Temporary MOC, that the power source will be needed over a 90-day period we need to ensure that the electrical power sources meet code for the time period needed for the “temporary” MOC. So although the change may be “temporary” as defined by our Management of Change procedure, any electrical power cannot exceed the 90-day window. A nice tip for our MOC programs is to not allow any “temporary MOC” extend beyond a 90-day window without an additional review and approval at the end of the 90-day period.