You've seen it (or more correctly - you've see the crap blocking it): Mounds of equipment stacked in front of Circuit Breaker Panelboards, Fire Hose Cabinets, Fire Alarm Pull Stations, Fire Extinguisher Cabinets, etc. How the heck is someone supposed to get to it if they can't even see it!?
Keeping a tidy house (or shop or stage) is a never-ending task. It requires that all personnel understand that you can't pile stuff in front of electrical panels and fire protection equipment. It doesn't matter if it is 5 seconds, 5 minutes, 5 hours, 5 days, 5 months - it can't go there.
So, what's a facility manager to do?
Stop-Painting.com has a solution: The offer BIG round floor-mounted signage dots that are 17.5" diameter. The electrical panel sign at left is one example of what they offer. They make custom-worded signs for other applications, too. For added durability, they also offer a clear epoxy resin sealer kit so that you can apply a protective coating over the signage dots.
They also offers their Superior Mark floor tape that is THICK and has beveled edges so it doesn't snag on rolling stock. You can get it in 36" pre-cut strips with 45 degree interlocked corners so they are easy to install and get the proper distance from the panelboard face. The strips come in six colors. Red is best for Fire Protection Equipment, and Yellow is best for Electrical Equipment.
Note that for high voltage panels that the clearance must be greater, and also note that the clear space is IN FRONT OF THE PANEL - not measured from the wall face. NFPA 70 NEC Reference: Chapter 110.26.
The code also requires that the width of the clear area be the greater of:
a.) The width of the equipment, or
b.) A minimum of 30".