3 replies to this topic

[SkiLiftsRock]

Hello all,

A poll of discussion on ANSI B77.1-2017 3.2.9 (Detachable) 4.2.9 (Fixed)

Quote

The aerial lift shall incorporate an audible warning device
that signals an impending start of the aerial lift. After the
start button is pressed, the device shall sound an audible
alarm for a minimum of 2 seconds and shall continue
until the aerial lift begins to move. The audible device
shall be heard inside and outside all terminals and
machine rooms above the ambient noise level.

Different types of signaling I have seen on installations with variations by operator preference, generation of implementation, modifications, or to be consistent with other local lifts. There are some with visual indications as well, however I am polling thoughts on audible.

• School bell (mechanical)
  
• Two tone horn (AB) electronic
  
• One tone horn electronic
  
• Sonalert
  
• Recorded electronic school bell
  
• Voice over recording "Attention - Lift Starting"
  
• Nothing
  
• Operator required to maintain contact for signaling
  
• 
  

Do you have a preferred implementation? One type for start alarm, another for signal? Same sound type for starting and signaling? Mechanical type vs all electronic loudspeaker style?

[comeagain?]

I'm not a fan of anything where the same sound is used for multiple indications. I also think a certain manufacturers recorded bell sound is atrocious, and even worse when it's triggered from a push button because of the delay. I also think it could be argued depending on the location that a voice recording wouldn't be universally understood depending on the location and demographics.

I'm personally against requiring the operator to maintain contact for the entire signaling. The longer you ask the operator to hold down buttons, the more likely you are to have them let go too soon. So then you end up with random signaling on both ends of the lift, potentially no motion, and to determine what happens if you let go too soon. Say the signal hasn't stopped, but the lift has started moving, do we then stop the lift again? And does it make the process any safer?

So my preference is that there be two sounds, either multiple tones from a single audible alert, two different audibles, or both a bell and an electronic signal. One would be controlled by the operator(s), one to be controlled by the lift to signal starting (or anything else that requires attention).

[SkiLiftsRock]

comeagain?, on 24 October 2021 - 10:24 AM, said:

I'm not a fan of anything where the same sound is used for multiple indications. I also think a certain manufacturers recorded bell sound is atrocious, and even worse when it's triggered from a push button because of the delay. I also think it could be argued depending on the location that a voice recording wouldn't be universally understood depending on the location and demographics.

I'm personally against requiring the operator to maintain contact for the entire signaling. The longer you ask the operator to hold down buttons, the more likely you are to have them let go too soon. So then you end up with random signaling on both ends of the lift, potentially no motion, and to determine what happens if you let go too soon. Say the signal hasn't stopped, but the lift has started moving, do we then stop the lift again? And does it make the process any safer?

So my preference is that there be two sounds, either multiple tones from a single audible alert, two different audibles, or both a bell and an electronic signal. One would be controlled by the operator(s), one to be controlled by the lift to signal starting (or anything else that requires attention).

Hey comeagain,

I appreciate your response and feedback. I agree on different sounds for different functions. Where digital integrations are now a more standard development on new installations, the 'signal' button has a delay before audio is played. Due to PLC CPU timing, the signal response time is not the same as a Sonalert on +24VDC circuit contacts.
I am working on a project, considering integrating two-tone startup alarm, and have the signal button play a refined school bell ring. One loudspeaker.

[2milehi]

School bell