Lomanco F0510B2497 Exactly Replaces older F0510B2944 on 6/2011 just 2 days prior to a heat wave in NYC.  Attic fan needed to lessen work load of central air conditioning attic heat exchange unit.  My older attic fan (installed around 10/2002) burned out after 9 years of service.  Confirmed live circuit and dead old motor; **Powered off circuit** ; removed old motor with fan assembly from attic fan mount - retested old motor again and confirmed dead; new motor tested OK pre-install; uninstalled BX cable cover and existing fan blades from old motor and reinstalled to this new motor onto attic fan mount(fan, cable cover, and fan mounting all fit perfectly); powered up circuit and all tested OK.  New motor works as it should.  ** Make sure the attic fan thermostat is set properly so the fan will cycle on and off with attic temperature needs! (Constant Off = hot attic = load on AC = less efficiency with higher electrical cost;  Constant On for 24/7 May possibly wear out motor prematurely - unnecessary electric cost.) **