(1) Two separate automatic stop devices shall be provided to cut off the power and apply the brake when a loaded step passes the upper terminal landing. One of these devices shall consist of a switch mechanically operated by the belt or stop roller. The second device shall consist of any of the following:

(a) A roller switch located above but not in line with the first switch;

(b) A photocell and light source (an "electric eye"); or

(c) A switch activated by a lever, bar, rod, or plate.

(i) If a plate is used, it shall be positioned above the head pulley so it barely clears a passing step.

(ii) If a bar is used, the bar shall be of the "breakaway" type.

(2) The stop device shall stop the lift before a loaded step reaches a point 24 in. above the top terminal landing.

(3) Once the lift has stopped, the automatic stop device shall be manually reset. Therefore, this device shall be located on the top landing where the person resetting the device has a clear view of both the "up" and "down" runs of the lift; and it shall be impossible to reset from a step.

(4) Electric stop devices shall meet the following requirements:

(a) All electric switches that directly open the main motor circuit shall be multiple type switches;

(b) Photoelectric devices shall be designed and installed so that failure of the light source, the light sensitive element or any vacuum tube used in the circuit will result in shutting off the power to the driving motor;

(c) In areas where flammable vapors or dust may be present, all electrical installations shall be in accordance with the NEC requirements for those installations; and

(d) All controller contacts carrying main motor current shall be copper to carbon types unless the circuit is simultaneously broken at two or more points or the contacts are immersed in oil.