Locked Rotor Alarm Signal Output (yellow wire lead): Under normal conditions a locked rotor alarm signal outputs a constant signal frequency... if the fan stops spinning or "locks", it then outputs a "LOW" condition signal. If the fan starts spinning again, the "LOW" condition signal will go away.
 
Features:
 
Dimensions: 40 x 40 x 20mm (1.57 x 1.57 x 0.79")
Mounting Center: 32mm (1.26")
Rating: 24VDC
Current: 0.13 Amps
Power: 3.12 W
Bearing: Sleeve
Speed: 6000 RPM
Noise: 26 dBA
Max Air: 7.09 CFM
Max Pressure: 3.91 mmH2O
Temperature: -10 to +70 C
Hours: 20000-30000
Termination: Wire leads
Weight: 40g
Impeller: Glass fibre reinforced plastic 94V-0 PBT
Frame: Glass fibre reinforced plastic 94V-0 PBT