Elevator World received a question from the Safety Codes Council in Edmonton, Canada, regarding a tweet from @BillMurray, a spurious account, not affiliated with the actor Bill Murray:
Members of EW’s Technical Advisory Group took the time to respond to this burning question. Here are their answers.
The technology has the ability to unselect a floor, but elevator manufacturers and building designers are not requesting such an option to be added for the general public’s use. Under Phase II operation, Firemen’s Service has the ability to unselect, or, better, cancel all registered car calls if the emergency responder is required to change the destination to preselected floors. Most elevator systems have what is called an anti-nuisance car protection operation, whereby if all car calls are registered at once, or four or more calls are registered without a sufficiently loaded car, all car calls are canceled.
Vertical Transport Technology Corp.
My initial impression would indicate it is certainly “doable” in today’s control-system technology, but the underlying issues could impact a lack of market presence. For example, taking cost versus insufficient demand into account, why is it necessary? ASME A17.1-2013/CSA B44-13 Section 184.108.40.206. (h) requires a “CALL CANCEL” button on the Firemen’s Emergency Operation (FEO) control panel (restricted access) to cancel all car calls (special purpose).
Then there are also operational safety issues. On selective/collective control systems, car calls, once entered, are held in queue until answered. Other than Phase II system capability to cancel calls from Code of Practice for Energy Efficiency of Lift and Escalator Installations, I’m not aware of any other systems that even offer the option to accommodate a cancelation request. Destination-dispatch systems, as I understand most OEM systems, do not accommodate car calls. However, there is one major control OEM that offers a car-call cancel option, but I sense it’s not a commonly exercised option.
COAKER & CO., P.C.
I believe the need to cancel a call is so rare, it is not a design element.
This function, deliberate loss of an unintended call, would be compared to the nuisance of inadvertent loss of an intended demand, also an undesirable occurrence. The ability to misuse the function should also be considered, where someone in a full elevator could deliberately cancel everyone’s calls, just to be a jerk. The full elevator would then be recalled to the lobby with users wondering why that occurred.
There are certain operations that permit or require car-call canceling. Many controller systems sense the number of car occupants or count users entering and exiting, and, should an unjustifiable number of car calls be entered, the system will cancel them for the sake of not wasting time and electricity. Firemen’s Emergency Operation (FEO) requires car canceling where the fireman may have entered the wrong floor and life and limb may be at stake.
All things considered, users generally press the correct button and only occasionally press the wrong one.
Elevator Safety Solutions, LLC
There is a ‘CALL CANCEL’ button that only functions when on Phase II of FEO.
I don’t recall the code committee ever discussing a call cancel for automation operation. I think it would lead to problems with persons canceling each other’s calls. Some control will automatically cancel calls if a stop is made at three floors and no one enters or exits. This is called ‘anti-nuisance’ and is to prevent someone from pushing calls for all the floors.
Zack McCain, P.E., QEI
American Society of Mechanical Engineers