July 12, 1999
Circular Letter E-99-2
T0: Installers and Manufacturers of Wheelchair Lifts and Other Interested Parties
SUBJECT: Stop Switch and Alarm Bell for Wheelchair Lifts
ASME A17.1-1993, Rule 2000.11 references Rule 211.1(a)(1) with regards to stop switches and alarm bells on wheelchair lifts. Rule 211.1(a)(1) implies that two switches are required to perform this function. The ASME A17.1 Main Committee makes many interpretations using the intent of the Code.
The Division has determined that it appears the intent of the code is not to require two devices to perform the two operations on wheelchair lifts, but that one device may perform both functions. This intent is proven out by the fact that Rule 2000.11 was revised in the 1997 addenda of the 1996 Code to indicate this. The revised rule indicates that a stop switch, which illuminates when activated and is identified also as an alarm is acceptable in meeting the requirement. Notice the clarification indicates the switch must illuminate not a light beside the switch. This revised rule is certainly justified by the fact that a wheelchair is operated by constant pressure operating switches only and release of the operating switch will stop the unit.
The Division will therefore accept one device performing the two functions on wheelchair lifts provided the switch itself illuminates.
James L. Meyer
Elevator, Ride and Tramway Unit