Summer Electrical Load Check: Is Your Panel Ready for Peak Demand?

Why summer overloads your electrical panel

Most US homes built before 2000 have 100-amp or 150-amp panels — sized for a pre-AC, pre-EV world. A central air conditioner alone draws 20–50 amps on startup (15–30 running). Add a pool pump (10–20A), EV charger (30–50A), dehumidifier (5–10A), and the usual household baseline, and you're flirting with the panel's maximum capacity. When demand exceeds supply, breakers trip — that's the best case. The worst case is overheated wiring behind walls, which is a leading cause of residential electrical fires. The National Fire Protection Association reports that electrical distribution equipment causes an average of 34,000 home fires per year in the US.

How to check your current load

• Find your panel rating: Open the panel cover. The main breaker (the big one at the top) shows your total capacity — typically 100A, 150A, or 200A. This is the ceiling for everything in your house combined.
• Add up your circuits: List every breaker and its amperage. The sum will far exceed the main breaker — that's normal, because not everything runs simultaneously. What matters is the peak simultaneous load.
• Calculate peak summer load: Add the running amps of everything that runs during the hottest hour of the day — AC, refrigerator, EV charger (if charging daytime), pool pump, cooking appliances. If this exceeds 80% of your main breaker, you're in the danger zone.
• Use a clamp meter: For $30–$60 you can buy a clamp-on ammeter and measure actual current on the main service wires during peak usage. This gives you real numbers instead of estimates.

Warning signs of an overloaded panel

• Breakers trip repeatedly, especially when the AC kicks on
• Lights dim or flicker when large appliances start
• Warm or hot breaker panel cover — the panel should be room temperature
• Buzzing or crackling sounds from the panel
• Burning smell near the panel or any outlet
• Double-tapped breakers (two wires on one breaker) — a sign someone ran out of slots and jury-rigged the wiring
• Scorch marks or melted plastic inside the panel

Panel upgrade: what's involved

If your load calculation exceeds 80% of capacity (or if you're planning to add an EV charger, heat pump, or pool), you likely need a panel upgrade. A 200-amp panel upgrade costs $1,500–$3,500 for the panel swap and $2,500–$5,000+ if the utility also needs to upgrade the service entrance (the wires from the street to your house). The project takes 1–2 days and requires a permit and inspection. Some utilities offer rebates for panel upgrades, especially when paired with electrification (heat pumps, EV chargers) — check with your local provider. A panel upgrade also adds resale value — buyers and home inspectors flag undersized panels as a negotiation point.

Quick fixes before upgrading

• Stagger high-draw appliances: Set your EV charger to charge overnight instead of during AC peak hours. Use a timer on the pool pump to run during off-peak times.
• Upgrade to a smart thermostat: Reduces AC runtime by 10–15% through intelligent scheduling. Costs $120–$250 vs. thousands for a panel upgrade.
• Check for energy vampires: Old dehumidifiers, second refrigerators, and space heaters in garages can draw 10–15A continuously and are often forgotten.

When to call an electrician

Any of the warning signs above — especially warmth, buzzing, or burning smell — warrant an immediate call. Even without symptoms, schedule an electrical inspection ($150–$300) if your panel is over 25 years old, if you have a Federal Pacific or Zinsco panel (these brands have well-documented safety issues), or if you're planning any major addition like an EV charger, pool, hot tub, or heat pump. An electrician can perform a formal load calculation (per NEC Article 220) and tell you exactly how much headroom you have.