Refrigerated Air Dryer Shaking Violently - Troubleshooting and Repair

Customer called with a refrigerated air dryer that would shake violently every time they tried to start it up. After a short shutdown period, the unit became completely unusable due to severe vibration.

In this video, I walk you through the complete diagnostic process to identify the root cause of this problem. What appeared to be a mechanical issue turned out to be an electrical fault causing the compressor starter to chatter rapidly.

*The Problem:*

Unit shakes violently on startup
Multiple restart attempts - same result every time
Customer had to shut down for safety

*Diagnosis:*

Confirmed violent shaking condition
Traced issue to chattering compressor starter contactor
Found faulty phase monitor causing intermittent signal to starter coil
Phase monitor contacts causing starter to rapidly cycle on/off

*The Fix:*

Temporarily bypassed faulty phase monitor
Restored unit to full operation
Recommended permanent phase monitor replacement

*Equipment:*

QPNC-1250(E17) Refrigerated Air Dryer
460V 3-Phase
R410A Refrigerant
Located in Bay Minette, AL

This is a great example of how an electrical component failure can mimic mechanical issues. Always trace your circuits and don’t assume the obvious answer is the right one!

*⚠️ Important:* The temporary jumper bypasses protective features. Always replace faulty safety components as soon as possible.

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#HVAC #Troubleshooting #AirDryer #CompressedAir #IndustrialMaintenance #Electrician #HVACTech #Repair #Diagnostic

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