View Full Version : Federal siren amperage

Kevin Lynch
05-15-2013, 08:32 PM
I'm installing a Federal model 77 coaster siren on my American LaFrance. This is the dual tone coaster. Makes the hair on your arms stand up.
We're going to put an in-line fuse in. Anyone know the amps on this siren????

Jack Ramsey
05-15-2013, 09:15 PM
From Federal's 1985-'86 Service Parts Index, after the 77's production. I understand its motor was shared with the 28/66.
http://i458.photobucket.com/albums/qq304/fyrboy1/Federal/img032_zps16f1fd0d.jpg (http://s458.photobucket.com/user/fyrboy1/media/Federal/img032_zps16f1fd0d.jpg.html)

James Fischer
05-15-2013, 09:28 PM
Thank you Jack, for posting this...Very helpful !! :thumbsup:

Kevin Lynch
05-16-2013, 10:06 AM
Wow i'll be sure to save this!!!! Thanks Jack

Kevin O'Connell
05-20-2013, 08:33 PM
I have the same service manual, and have found Federal's numbers to be somewhat optimistic. There is a calibrated ammeter on the test bench at B&M that has never seen a Q draw under 125 amps maintenance current, or less than 310 amps inrush current.

Most apparatus manufacturers don't use a fuse, but those who do use a 300 amp for the Q and a 200 amp for a B&M. For your Double Tone a 200 amp fuse is adequate, with #4 cable minimum. If the cable run is more than 10' total, use #2 cable.

The reason for the high amperage fuse is that it must be able to withstand the brief surge of inrush current.

For reasons we'll never know, Federal used the Autolite MAB/MBB motors (3-1/2" dia.) on the Double Tones long after the other models went to the Prestolite MDS series motors. Both motor types were used on all Class 60, 70, C and Q sirens.