What Causes Circuit Breakers to Trip and How to Prevent It

As homeowners, we’ve all experienced the annoyance of a tripped circuit breaker. The lights go out or the AC shuts off unexpectedly, and you’re left resetting the breaker to get things running again. But what actually causes a circuit breaker to trip? And more importantly, how can you prevent it from happening in the first place?

Circuit breakers are essential safety devices found in modern electrical panels that cut power to a circuit when they detect an overload or short circuit. This prevents fires, damage to wiring and electronics, and electrocution hazards. By understanding common trip causes and following some best practices, you can avoid many preventable circuit breaker trips.

Major Causes of Circuit Breaker Tripping

There are a few main reasons why a circuit breaker will trip and cut power:

Overloaded Circuits

The most common cause of breaker trips is overloading a circuit. This happens when you draw more amps of power on a circuit than the breaker is rated for. For example, a 15 amp breaker wired to a bedroom circuit with too many outlets and devices plugged in may overload when you run multiple appliances at once. The breaker trips to “break” the circuit and protect the wires from overheating.

Short Circuits

A short circuit occurs when electricity takes an unintended detour around damaged wiring with very low resistance. This creates excessive current flow that immediately trips the breaker. Short circuits are often caused by loose or miswired connections, damaged insulation exposing bare wires, moisture, pests chewing through wires, or overdriving staples piercing cables.

Faulty Breakers

Circuit breakers themselves can malfunction and trip due to mechanical issues, worn contacts, corrosion, or manufacturing defects. Old breakers also become less accurate over time and may trip more readily. Ground fault circuit interrupters (GFCIs) and arc fault circuit interrupters (AFCIs) are very sensitive to tripping when they detect leakage currents or arcing, respectively.

Power Surges

Spikes in voltage levels from lightning strikes, damage to power lines, or heavy electrical loads turning on can potentially trip breakers. Surge protectors help suppress power surges.

Moisture & Corrosion

Exposed copper wiring that gets wet or corroded can lead to short circuits, reduced conductivity and overheating that may trip breakers. Moisture leaks in wiring near pools, crawlspaces, attics and basements are common sources.

9 Ways to Prevent Circuit Breakers From Tripping

Here are some tips to help minimize nuisance circuit breaker trips in your home:

1. Avoid Overloading Circuits

Check the wattage demands of devices and appliances plugged into each circuit to make sure you don’t exceed the rated amperage of the breaker. Spread load across multiple circuits to prevent overload trips. For example, plug refrigerators and freezers into their own dedicated circuits.

2. Upgrade to a Larger Service Panel

If your home’s electrical needs have expanded beyond the capacity of an outdated, small-capacity panel, upgrading to a 200 amp or larger panel with more circuit spaces may be needed to handle added load. An electrician can assess this.

3. Inspect and Tighten Connections

Loose wire connections from vibrations, aging, improper installation or overheating can increase resistance and trip breakers. Check that all circuit wiring connections at outlets, switches, junction boxes and the main panel are securely fastened.

4. Replace Old or Faulty Breakers

Worn or defective breakers that won’t reset properly or continuously trip should be replaced. Breakers do wear out over time. Consult an electrician to install new breakers to match your panel and wiring.

5. Address Moisture Problems

Prevent moisture from infiltrating indoor and outdoor electrical components. Check for leaks, properly ground outdoor wiring, seal openings, and keep crawlspaces and basements dry. Consider having an electrician evaluate and remedy any compromised wiring.

6. Balance Multi-Phase Loads

For three-phase power systems, evenly distribute electric loads across each phase to prevent overload trips from imbalanced demand. An electrician can shift circuits to balance the draw if needed.

7. Install Surge Protectors

Protect sensitive electronics and prevent voltage spikes from reaching breaker circuits by installing quality UL 1449 certified surge protectors. They divert excess power surges safely to ground. Install them at your main electrical panel, power strips and directly on large appliances.

8. Hire an Electrician for Inspections and Maintenance

Prevent hazards before they happen by having a licensed electrician routinely inspect your home’s electrical system and panel and perform preventative maintenance. They can detect issues early like overloaded circuits, faulty connections and corrosion, and make needed wiring upgrades and repairs.

9. Call an Electrician for Unknown Tripping

If you have circuit breakers tripping frequently and randomly for unknown reasons, it likely indicates a potentially hazardous underlying electrical problem needs diagnosis and correction. Hire a professional electrician to safely track down the issue. Don’t ignore it.

Diagnosing the Underlying Cause of Nuisance Trips

When a circuit breaker trips repeatedly under normal loads, don’t just keep resetting it blindly. There’s likely an underlying issue needing correction, especially if the tripping is isolated to just one circuit. Here’s how to investigate the cause:

• Carefully check the circuit wiring and all connections for any visible signs of loose, damaged or burnt wires.
• Plug in and run appliances one at a time to isolate which outlet or device may be overloading the circuit when turned on.
• For short circuit possibilities, unplug or disconnect all loads from the circuit, then reset the breaker to see if it trips with no loads at all. If so, a wiring short is likely.
• Check if any recent electrical work may have miswired the breaker or circuit.
• For AFCI or GFCI breakers, press their test buttons to see if that triggers the trip. If so, a ground fault may exist.
• For multiple overloaded circuits, calculate your home’s overall electrical needs to determine if your service panel is underpowered for your usage requirements.

If you’re unable to determine the trip cause yourself, it’s safest to have an experienced electrician troubleshoot further. They have the proper training, equipment and expertise to diagnose the issue and prescribe the necessary repairs.

When to Call an Electrician

While many basic tripping issues can be DIY-prevented with load monitoring, tightening connections, and breaker replacements, it’s wise to involve a professional electrician for the following scenarios:

• Your main breaker or multiple branch circuit breakers trip frequently
• Breakers trip randomly and repeatedly under normal loads
• You cannot determine the cause of nuisance tripping yourself
• There are signs of damaged, burnt or severely overheated wiring
• GFCIs or AFCIs won’t reset or trip with no loads present
• Your home still has outdated 60 amp fuse boxes
• Power fluctuations, flickering lights or dimming occur throughout your home

Electrical issues are not always DIY projects, especially when complex wiring faults, shorts and safety hazards are involved. Licensed electricians have the expert know-how, equipment and training to correctly diagnose and fix tripping issues. They can also advise if your entire electrical system needs upgrading to avoid chronic breaker trips.

By understanding the common causes of circuit breaker trips and following overload prevention best practices, you can minimize annoying power disruptions. But when a breaker does trip repeatedly under normal conditions, never ignore it. Identify the source of the problem and remedy it before a more serious issue arises. With proper electrical maintenance and upgrades over time, your home’s circuits and breakers will operate safely and reliably for years to come.

Learn the main causes of circuit breaker tripping including overloads, shorts and faulty breakers. Discover pro tips to prevent nuisance electrical breaker trips.

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