The Siren Board

The Federal models 5 and 7 look near identical, thus making identification difficult. Is their a way to easily identify the two models?

I would agree it's hard to tell between the two models but my theory is that the Model 5 has a 5 HP motor while the Model 7 has a 7 HP motor. The Model 2 is still sold today and according the the specs from Federal Signal, the Model 2 is 2 HP.

AST128_RyanK wrote:The Federal models 5 and 7 look near identical, thus making identification difficult. Is their a way to easily identify the two models?

Not really. There technically seems to be no difference between the two, and most Model 5's and 7's have 7.5 or 10 horse motors. Model 3's had 5 horse motors. The old Fedelcode Model 5's though are distinguishable by the little service door on the housing.

I believe some of the earlier Model 5s did use a 5 HP motor. They have a much longer startup (wind-up) compared to the 7.5 or 10 HP motored examples. The actual 5 HP sirens are not so common as it was easier for Federal to just use the stronger 7.5 or 10 HP motor on both the Model 5 and Model 7. In a nutshell, the Model 5 and 7 are the same siren.

The majority of Model 5s and Model 7s use a motor rated at 7.5 or 10 HP. They were labeled as 5 HP to get around local rural electric mandates. In the early 20th century, rural electric companies did not have much electric capacity to work with and they were concerned that motors too large would hog up too much electricity from the grid. Usually they would not allow motors bigger than 5 HP across the lines. Their concerns were largely redundant as none of these sirens ever gave problems with the electric grid.

Model 5s and 7s made prior to 1959 had a maintenance hatch door in the shroud which gave access to the motor. This was later omitted.
By this point, the Model 7 legion was dropped and all Model 5 sirens were still using 7.5 or 10 HP motors.

Don't forget that the C3 1/2 is also the same siren.