🔧 DIY AC Troubleshooting Story – TRANE 3-Phase Units

Описание: 🔧 DIY AC Troubleshooting Story – TRANE 3-Phase Units
I was called to inspect a 3-ton TRANE 3-phase AC that had a very loud noise at compressor startup.
Not a normal startup hum — it sounded rough, like a crank or mechanical knock 😬
🧐 Initial Checks
• Electrical supply ✔️
• Compressor condition ✔️
• Wiring… 🚨 problem found
⚠️ What I discovered
• A 2-pole contactor was used on a 3-phase compressor
• One phase was connected directly to the compressor, bypassing the contactor
• The contactor poles were not picking up simultaneously
This caused:
• Phases engaging out of sync
• Compressor starting on uneven phase timing
• Result: loud cranking / knocking noise ⚡⚙️
🛠️ Fix Applied
• Replaced the contactor with a proper 3-pole contactor
• Rewired all three phases correctly through the contactor
• Ensured simultaneous phase engagement
✅ Result
• Smooth startup
• No abnormal noise
• Compressor running normally
🔥 Bonus
I applied the same correction on a 5-ton TRANE 3-phase AC that had a similar startup noise — and it worked perfectly 👌
📌 Lesson Learned
Using a 2-pole contactor on a 3-phase compressor is a disaster waiting to happen.
All phases must engage together, or the compressor will suffer.
#DIYHVAC #TRANE #ThreePhase #CompressorNoise #WrongContactor #FieldFix #HVACTechnician #ElectricalMistake #ACRepair #RealWorldHVAC