Huh, intresting!Federal Signal fan wrote: ↑Sat Aug 01, 2020 8:56 amWelcome!
We use Federal Signal Model Ls for overhead cranes in our new rolling mill at my work. Overhead cranes typically are 480VAC and 480V to 240/120V transformers are common and usually installed for control power and that includes the siren. This voltage also allows the siren to be used on regular control and branch circuits you can find around business and houses.
A lot of old cranes are DC, and use 250VDC. We also have a Model L on one of our old 250VDC cranes, and they use 250V for both main power and control. Having a siren that can take 240/250V AC or DC is very useful when stocking sirens in a parts warehouse when you have different types of cranes. In this case, you can take both the newer AC powered and older DC powered cranes and use the same siren. On the AC crane you could take the 240VAC coming off of both legs of the 480 to 240 transformer and use a contactor to sound the siren on command. On the DC crane, you just use the positive and negative with 250VDC between them through a similar arrangement using a DC contactor.
Another reason for using a higher voltage is that it allows you to drop the amount of amperage drawn by the siren while maintaining the same electrical power. A small siren like this, however, doesn't seem to benefit too much from that. The 240-250V AC/DC model is much more for convenience of voltage availability. On bigger sirens, however, you will find a different story with starting and running larger motors.
Cheers!
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