I don't chime in much here anymore but Driver, I think a lot of the hesitancy to address your questions, is that it just takes too much time to respond. For instance. The link below if just for the QEI recertification test.
https://naesai.org/UserFiles/5_Houston_TX_flier_2014_2.pdfNotice all the books required just to prepare and take this test.
A17.1 / CSA B44 Safety Code for Elevators and Escalators
• A17.2 Guide for Inspection of Elevators, Escalators and Moving Walks
• A17.3 Safety Code for Existing Elevators and Escalators
• A18.1 Safety Standard for Platform Lifts and Stairway Chairlifts
• NFPA 70 National Electrical Code
• QEI-1 Standard for the Qualifications of Elevator Inspectors
• Elevator Industry Field Employee’s Safety Handbook
• And more
These books alone require a couple of grand and hour upon hour of study just to be up with the current codes, which are constantly changing.
And that's just to inspect them and be up on current code. And to work on them opens a complete new set of educational requirements. A rigoruous 5 year course with overseer's from the government, Companies and Unions. Course descriptions below.
http://www.neiep.org/courses/default.aspxThat's not counting all the company classes, adjuster classes,Night classes for advanced degrees (Usually in electronics or computer architecture, or programming).
And yes. In my 35 years I have witnessed the scenario you describe. An older open loop control from the 60's. Not seen it on any of the newer controls because of built in safety redundancy. There are just so many possibilitys to your scenario, I'm sure everyone here on this board could dream of this happening if X,Y,Z happened on Control type Q...
Probably wont post here for a long time again, but that's just too much hassle.
Hope that helps Driver
