Your RV’s Main Breaker Keeps Tripping? What to Do

Note: Working with Electricity is dangerous. Only proceed if you’re competent and have the necessary skills wot work with electricity safely.

If your RV’s main breaker keeps popping, whether instantly or randomly, you may want some guidance on what to check and fix so that you can fix the underlying fault as quickly and safely as possible.

If you find yourself in this situation, then read on. This post lists the common reasons why the main breaker might be tripping, and what checks you can do to identify and fix the fault so that you use the appliances in your RV without interruption.

Quick Answer

If the main breaker keeps tripping it’s likely that there is an internal short on one of the 120V AC circuits connected to the main circuit breaker. It could also be that the breaker itself is faulty. Read on for more information on why the main breaker may be tripping.

4 Reasons Why the Main Breaker is Tripping

If the 20, 30, or 50 amp main circuit breaker keeps tripping check the following:

#1. There is a current overload by the connected appliances exceeding what the breaker can handle. Work out the combined current draw of the connected appliances and compare it with the main circuit breaker rating.

If it works out really close or over then it is probably an overload issue. You’ll need to manage the connected loads by running selected appliances at a time to ensure the current draw does not exceed what the main circuit breaker can handle.

For example,

  • 1,200-watt, 120V microwave draws about 10 amps at full power
  • 1,500-watt water heater rated 120V AC draws about 12.5 amps at full power.

If both appliances are switched on then the combined current draw of these two appliances exceeds 20 amps (10 amps+12.5 amps) and will therefore trip a 20 amp main circuit breaker.

An appliance with an excessive current draw. Monitor the current draw with the connected appliances using a clamp meter.

It could be that the current draw from the connected appliances exceeds the breaker capacity.

#2. The supply voltage is low (less than the rated 120V AC for the appliance). If the voltage supply from shore power is low then the current draw from the connected appliances will be considerably higher than usual and may lead to the circuit breaker tripping.

You can use a clamp meter set to read AC voltage to read voltage and confirm if this is the issue. You may also be able to confirm this by switching to a generator supply and checking if this is the cause.

#3. One of the connected appliances is faulty. Faulty wiring or a faulty appliance – converter, AC, fridge, or other can also trip the main circuit breaker. To identify which circuit may be tripping the circuit breaker, use a clamp meter.

Disconnect all the branch circuits connected to the breaker – converter, water heater, AC, or others and then reconnect one at a time, while monitoring the voltage at the breaker with each connection.

Does the voltage drop noticeably? Does the breaker trip? If so then this can help you narrow down which appliance or wiring is responsible for the repeated breaker tripping.

#4. The main circuit breaker is faulty. Circuit breakers fail too and need to be replaced.

How to Tell if the Breaker is faulty

To test whether it is a faulty breaker or otherwise, you can isolate the circuits connected to the breaker and instead connect a space heater or any other heater to the breaker.

Let the circuit breaker power the heater for several hours. Does the main circuit breaker still pop? If not then quite likely the breaker is intact.

If it still trips, then you probably have a faulty breaker. Replace the breaker and check if this clears the repeated tripping.

Related Topics

Why the Main Circuit Breaker may be Tripping Randomly?

If the main circuit breaker trips randomly it may be because the wire connections to the breaker are loosely connected. Loose wire connections are prone to sparks and heat buildup which can trip the breaker. Also, inspect the pathways for the wire connections to each of the connected appliances.

Are they exposed to moisture or water from a leak? Moisture or water buildup around a wire connection can cause a short that trips the breaker.

The random nature of the tripping can be explained by the presence or absence of water at a wire connection. When it is not exposed to water there is no short and the breaker works fine until it is exposed to water. Could this apply to your situation?

Closing Thoughts

If your RV’s main circuit breaker is tripping, check for overloading by the connected appliances or a fault in the wiring.

Other possible causes of tripping include low voltage from shore power supply or even a faulty breaker. Any of these can cause the main circuit breaker to trip repeatedly.

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