PART VI | LESSON 27: VALIDATE FOR PEOPLE MATERIAL HANDLING ACADEMY
DRIVING QUESTION Is this system safe for the person who works beside it and fixes it at 2 AM?
THINK LIKE THE OPERATOR
  1. Where do I stand all shift, and what's moving next to me while I do?
  2. Where do I reach in to clear a jam, and what's got my glove if I do?
  3. Where am I at 2 AM when the line's down and I'm the only one in the building?
  4. Can I reach the disconnect from the floor without a ladder, and lock it out by myself?
  5. If I'm working under this run, is anything going to fall on me?
  6. If I open this gate, does the cell actually stop, or is that just a limit switch?
  7. Am I close enough to a pull cord to grab it before the belt takes more than my glove?

The Five Categories, Every Project

Underside

Belt and roller protection wherever an operator has access below the unit.

Pull Cords

E-stops along any run an operator can reach.

Caging

Around automated cells and robotic equipment.

Bearings + Shafts

Covers and guards at every drive location.

Pinch Points

Wherever a hand, a glove, or a sleeve can get caught.

THE CORRECTION

There's no universal height that exempts a conveyor from underside guarding. ASME B20.1 sets the duty by exposure: guard wherever falling material or a reach-in could endanger someone below, regardless of mounting height. The 6 ft 8 in figure is an overhead clearance minimum, not an exemption, and OSHA's 7-foot rule is for exposed power-transmission parts, not conveyor belly pans.

DESIGN PRINCIPLE Guard by exposure, not by a number.