Professional HVAC Motor Tester for Quick Fault Diagnosis This universal D.C fan motor tester simplifies troubleshooting for HVAC technicians and DIY enthusiasts. Designed for 3-wire and 5-wire D.C motors, it detects issues like motor failure, speed inconsistency, or abnormal feed back signals. The digital display instantly reveals RPM frequency, while the 310V short-circuit protection safeguards both the tester and motor during testing. Hassle Testing with Intuitive Design Color-Coded Ports: Match wires effortlessly: Red → 310V | Black → GND | Yellow → VSP (speed control) Blue → FG (speed feed back) | White → 15V (VCC) 3-Wire/5-Wire Switch: Toggle modes for compatibility with standard D.C motors. Adjustable Speed Knob: Simulate real-world operating conditions by gradually increasing motor speed. Built to Sturdy Housing:Good casing resists accidental drops or impacts. Short-Circuit Protection: Automatically cuts off power if 310V overload is detected. How to Use: Connect Wires: Match motor wires to the testers labeled ports (check motor nameplate for correct functions). Select Mode: Press/pull the 3-wire/5-wire switch based on your motor type. Test & Diagnose: Slowly turn the speed knob. If the motor accelerates smoothly and the screen displays rising RPM frequency → motor is healthy. If no rotation, unstable speed, or abnormal frequency → motor fault detected. WARNING: Always double-check wire functions before connecting to avoid burnout. Do not connect NC (empty) ports.