Section 7.231. Machines

(a) Types. Machines shall be of the direct-connected type or shall be driven by multiple V-belts. Cast iron gears shall not be used.

(b) Brake. A mechanically-applied, electrically released brake shall be applied to the motor shaft for direct connected units or to the input shaft for belt-driven units. The brake shall be capable of stopping and holding the manlift when the descending side is loaded with 250 pounds on each step.

(c) Belt. Belts shall conform to the following:

(1) Material. The belts shall be made of hardwoven canvas, rubber-coated canvas, leather, or other material meeting the strength requirements of paragraph(s) of this subsection, and having a coefficient of friction such that when used in conjunction with an adequate tension device it will meet the brake test specified in subsection (b).

(2) Width. The width of belts shall conform to the following:

Minimum Width (in inches)	Total Travel (in feet)
12	0—100
14	100—150
16	More than 150

(3) Strength. The strength of belts shall be not less than 1,500 pounds per inch of belt width for belts having a distance between pulley centers not in excess of 100 feet and 1,800 pounds per inch of belt width for belts having a distance between pulley centers of over 100 feet but in excess of 200 feet for over 200 feet, 2,450 pounds per inch of belt width.

(4) Belt fastenings. Belts shall be fastened by a lapped splice or shall be butt-spliced with a strap on each side of the belt as follows:

(i) For lapped splices, the overlap of the belt at the splice shall be not less than three feet when the total travel of the manlift does not exceed 100 feet and not less than four feet if the travel exceeds 100 feet.

(ii) When butt splices are used the straps shall extend not less than 3 feet on one side of the butt for a travel not in excess of 100 feet and 4 feet for a travel in excess of 100 feet.

(iii) For 12 inch belts, the joint shall be fastened with not less than 20 special elevator bolts, each of a minimum diameter of 1/4 inch. Such bolts shall be arranged symmetrically in five rows so arranged as to cover the area of the joint effectively. Reference should be made to Exhibit B of § 7.232 (relating to exhibits—safety diagrams).

(iv) The minimum number of bolts for a belt width of 14 inches shall be not less than 23 and for belt widths of 16 inches, the number of bolts shall be not less than 27.

(5) Pulleys. Drive pulleys and idler or boot pulleys shall have a diameter of not less than 20 inches.

(d) Pulley protection. The machine shall be so designed and constructed as to catch and hold the driving pulley in the event of shaft failure.