June 7, 2002
Circular Letter E-02-01
T0: Elevator Companies, Elevator Inspectors and other Concerned Parties
SUBJECT: Hoistway Door Interlock Control Relays
The subject matter contained in this Circular Letter is related to a similar situation addressed by Circular Letter E-93-1 which is attached for your reference.
Recently while making yearly elevator inspections for the operating permits in Los Angeles County, inspectors found several elevators that would run with the hoistway doors open. These elevators were removed from service immediately. It is hard to imagine amore dangerous condition than an elevator running with the hoistway doors open.
The elevators were using two "Magnecraft" relays for the hoistway door interlock protection circuit. Residual magnetism had built up over time and the relays were being held in the closed position. The elevators were approximately 8 to 12 years old.
Any malfunction of the relay to operate in the intended manner will allow an extremely dangerous condition to occur.
The Division is requiring the "Magnecraft" relays used for door Interlock protection to be replaced immediately. New relays may be other brands of relays. The relays shall be designed for the intended use, and arranged so that a failure will allow the relay to open.
It is fortunate that no one has been injured or worse because of this unsafe condition. Elevator companies aware of this condition must make the replacement immediately. If the elevator owner will not authorize the change, please notify the local Elevator Unit Office at once and the appropriate steps will be taken.
Principal Safety Engineer
DOSH – Elevator, Ride and Tramway Unit