High Amps High Temps

🌡️ RV A/C Trips the Breaker After 10 Minutes? Here’s What We Found

RV Type: 2017 Coachmen Chaparral 371MBRB Fifth Wheel
Service Date: May 24, 2025
Issue: Dometic rooftop air conditioner tripping the breaker after 10 minutes of use

🔍 The Problem

A customer called with a frustrating air conditioning issue: their Dometic rooftop unit would start up and cool normally—but after about 10 minutes of operation, it would trip the circuit breaker.

With summer heat and humidity climbing, they needed a fix fast.

🧰 Diagnosis

I began troubleshooting at the power distribution panel. All breakers tested fine, and I found no issues with wiring or loose connections. Next stop: the rooftop A/C unit itself.

After removing the shroud, I inspected the evaporator and condenser coils—they were clean, with unrestricted airflow. I then tested the capacitors, which also checked out within factory specifications.

At this point, I suspected a high current draw issue. Using a clamp on amp meter, I measured amperage on the compressor’s blue wire (power in). It started at 16 amps and steadily climbed past 18 amps—well above the Rated Load Amps (RLA) of 13.2 listed on the unit’s data label.

I also checked the compressor windings and found no shorts to ground, ruling out a simple electrical fault.

🧠 Likely Cause

Excessive amp draw on a sealed RV A/C system typically points to one of two issues:

1. Failing Compressor – The internal windings may be breaking down, causing it to work harder and draw more power than it should.

2. Refrigerant Blockage – A restriction in the cooling circuit could prevent proper refrigerant flow, forcing the compressor to overwork and overheat.

Both scenarios are common among RV techs and supported by field reports from the RVTAA technician community.

✅ The Fix

Unfortunately, RV rooftop A/C units are closed systems—the refrigerant circuit cannot be serviced or recharged. So, whether the issue is a failing compressor or a refrigerant blockage, the solution is the same: full unit replacement.

In this case, I recommended a new rooftop A/C install to ensure safe and reliable cooling for the rest of the season.

💡 Takeaway

If your RV air conditioner is running briefly then tripping the breaker, don’t wait—this kind of high amp draw can indicate a compressor on its way out. And since rooftop units are sealed, early diagnosis can help you plan ahead instead of losing your A/C during a heatwave.

Need expert RV air conditioner service?
I’m a certified mobile RV technician serving the Mississippi Gulf Coast, and I have experience in diagnosing and replacing rooftop A/C units. If your unit is overheating, underperforming, or keeps tripping breakers, call a pro before it fails completely.