Model 3 Info

[theroofable]

I had the privilege of working on a Model 3 siren. However, I do not know much, or really anything about these. Anyone know what years these were manufactured? This was a single phase unit that was not working. Glad to say it is back in service for fire calls now.

[EOWS1212man]

What is interesting is that model 3's is that they have the same chopper/stator that 2001's use, that's why they are usually a tad higher pitched than the 5 and 7. The housing is also a little bit different too, it's a little smaller, and the top cone and louver are the same diameter. Glad to hear it got a new lease on life!

[Jim Z]

to nitpick, the reason 2001s are higher pitched is because the DC motor isn't inherently speed limited like an induction motor is. 2-pole induction motors are limited to ~ 3500-3550 rpm with no load, and typically sirens would run them at 3450. The 2001's motor is powerful enough to spin the chopper up to 3950 rpm (in the 2001-130.)

[theroofable]

Good info to have. Any idea on a manufacture date of these units? I do have a recording of it that I may upload sometime.

[estokke09]

At least 50 years ago, that's when my town said they bought theirs. It has since been replaced by a T-121 and is currently restored and on display in my basement.