The Siren Board

I’m sure I’m not the first to notice this, but why do some T-128’s rotate counterclockwise as the Rotation sticker says —> and some newer models Rotate Clockwise with the arrow pointing <—.
From my experience the older models rotated counterclockwise, as the ones in Brecksville that were put up in 2005 do.
I’ve also observed however that newer models rotate clockwise instead. Any reason why some newer models rotate counterclockwise and others don’t?
I’ve also noticed that on the older models the rotator would stay going for a few seconds upon wind down; whereas with the newer models, everything stops on wind down.

Here’s a couple examples I found on YouTube:



https://www.youtube.com/watch?v=zwwedYUOHNc
(My Video) Older Model, Counterclockwise Rotation, Rotator stays on a bit after wind down



https://www.youtube.com/watch?v=blB4Q9EPqIQ
(Not My Video) Newer Model, Clockwise Rotation, Rotator turns off immediately on wind down

I just happened to wonder why they would change the rotation on some models and not others, as not all newer models stop rotating immediately on wind down or rotate clockwise. It just seems weird they wouldn’t make them uniform.

(Don't take my word on this matter, as what follows in my post is pure conjecture and might not be true, I have never seen in person a operational ASC controller so I can't confirm nor infirm if that is true or not, feel free to correct me if I'm wrong in my statements)

Probably some changes that ASC done to the controllers, sometimes (very commonly) manufacturers refactor their products to address some issues, or maybe the way the controllers are programmed (for instance, some are programmed to shut off immediately the rotation when the siren's rotor (chopper turbine) starts running down), another possibility is because of the way they were wired up and installed (for instance nothing prevents you to reverse the wiring on a rotating siren so it rotates counter-clockwise, just like on the older ACA rotating sirens excluding their 3phase version ( the 3 phase models are a special case))

i believe they switched rotator mechanisms as they were having bad issues with them. anyone care to correct me?

All you do to change rotation is swap the wires to the rotator. They run on 48 volt dc. I'm not sure why they would need different rotations though. I have a few T-128s for sale if anyone is interested.

Like you can reverse-wire a P-50?

Phone Goat wrote: ↑

Tue May 29, 2018 1:18 pm

Like you can reverse-wire a P-50?

You can swap one of the3 hot/phases wires with the neutral (IIRC) but Reverse wiring is more common on single phase units (in that case, T-128/135 (not to confuse with the P-50)s rely on a single phase DC motor, nothing prevents you to swap the pos/neg of the motor.)

Phone Goat wrote: ↑

Tue May 29, 2018 1:18 pm

Like you can reverse-wire a P-50?

As in reverse the rotation? You switch the rotator motor poles around I believe. As in reverse chopper rotation? Yes, as the guy mentioned above. Kills output though.

With the newer ASC rotationals, the sirens will continue to rotate only if they complete their entire cycle (3 mins usually) without being manually turned off or a cancel tone being sent. Upon the "Cancel" tone being sent, everything has to stop immediately, power to the chopper and rotation mechanism. The same holds true for most electronics. Usually they will "wind down" if they are allowed to complete their cycle, however if they are cancelled before the end of their cycle, often they will just cut out and stop making noise instantly.