Model L Problem

[motorsgears]

Hi guys,

In October I got a Federal Model L siren which I attached to the outside of my house. It is a 240v model, but I run it on 120v since I live in a highly populated region and only need a signal for a very small area. I have done a brief growl test weekly and it has worked perfectly from October until January 2. On Monday (January 5) there was a slight rubbing or catching sound. I just tested it again tonight and the problem is significantly worse (I'll attach links to videos of the tests). I live in Ontario, Canada and this problem has coincided with dramatic weather extremes. On January 3 the temp. was 15F and we got 7 inches of snow. The next day temperature got to 32F and fell back to 15F with rain changing to freezing rain (and a flash freeze). On the day when I first heard the problem there was an extreme cold warning in effect. Tonight it is even colder, about -18F and the siren sounds awful. Do you think there could be ice and/or snow clogging the siren? Could it be the cold weather or does it sound like some other problem? Should I stop testing until the spring? I'm sorry about all the questions, I'm just a little worried.

The video of when I first noticed the slight rubbing sound (note that I turned the siren off, it doesn`t just stop). Sound is around 5 secs.

https://www.youtube.com/watch?v=y0Z449PQ0tI


The second test where it sounds horrible

https://www.youtube.com/watch?v=F33yNMMOKpA

[Stormsetter4]

Sounds like the bearings are froze up. That Can happen with small bearings like that. Some water may have gotten into one of the bearings and froze.

[motorsgears]

Thanks for your reply. I really appreciate it. I've never dealt with this problem before so I have a few more questions. Do you have any suggestions as to what to do about the problem? How big a problem are frozen bearings? Do you think I'll need to replace them? Once they thaw in the spring will the siren be functional again? It's only used in the spring/summer anyways.

Thanks again

[Lily D]

I heard somewhere that motors have been known to freeze in extreme cold, that's why Canadian Model 2s are built differently. It might be a good idea to bring the siren inside in the winter. Hope that solved your problem.

[motorsgears]

Update: The temperature rose to about 16F so I tried the siren again today. It now sounds much better, much like the first video with the slight rubbing. This makes me think it may not be ice in the bearings, since the temperature has stayed well below freezing and there's no way it could have melted. I guess it could be a combination of the motor not handling the extreme cold well and some ice also. I just hope it lives! Thank you for your responses.

[sirendude2012]

It's likely the effect cold temperatures have on metal. Cold temps make metal shrink, so in this case, the outside of the bearing may be shrinking more quickly than the inside due to it's location being slightly closer to the chilly temperatures than the inner part of the bearing. As tiny of a difference as it may be, it matters.

The same thing occurs on my Trombone during the Holiday Parade. The outer slide is closer to the cold than the inner slide, meaning the slide's tolerances grow tighter. In one instance last year, the tolerances became too small and the slide froze in place, solidly. I could not budge it until I warmed the outer slide up, thus making the brass expand again.

Likewise, in a ball bearing, the outer band of the bearing shrinks more quickly than the inner ring, thus making the tolerances on the balls tighter. This makes the balls themselves move less freely. The colder it is, the further the extent of the shrinking.

[motorsgears]

Thanks sirendude! That actually makes a lot of sense. I guess I should probably stop testing it until spring then.

[Sirenfan1000]

I used to run my Model L 240 all the time on 120 and eventually the motor burned up. So I wouldnt run it on 120 for very much longer