How to read it, when to upgrade it, and what those breakers actually do
Your electrical panel is the heart of your building's power system. Most homeowners and property managers never open it unless something trips. But understanding what's in there — and what it means — can save you from fires, equipment damage, and code violations.
Every panel has a label inside the door — manufacturer, model number, and maximum amperage rating (100A, 200A, 400A). This rating tells you the total capacity of your service. If your building demand exceeds this number, you're living on borrowed time.
The label also lists the acceptable breaker types. Using the wrong breaker — like sticking a Square D breaker in a Siemens panel — creates loose connections, arcing, and fire hazards. We see this in the field more than you'd think.
AFCI breakers (Arc Fault Circuit Interrupters) detect dangerous arcing conditions — like a wire staple piercing insulation or a cord crushed under furniture. They've been required in bedrooms since 1999 and expanded to most living spaces by NEC 2017. If your panel doesn't have them, you're not up to code.
GFCI breakers (Ground Fault Circuit Interrupters) detect current leaking to ground — the kind that happens when electricity finds a path through water or a human body. Required in bathrooms, kitchens, garages, exteriors, and any damp location. They trip in 1/40th of a second. That's the difference between a shock and a funeral.
If someone tells you AFCI and GFCI are "optional upgrades," they don't know the code — or they don't care. These are life-safety devices, not luxuries.
Breakers trip frequently under normal use
Buzzing or humming sounds from the panel
Burn marks, melting, or scorching on breakers
Panel feels warm to the touch
Lights dim when appliances start
Using adapters or double-tapping breakers
Your panel is Zinsco, Federal Pacific, or Pushmatic
A typical modern home with gas appliances can run on 100A — barely. Add central AC, electric appliances, a home office, and an EV charger, and you're looking at 200A minimum. We've done 400A services for homes with pools, workshops, and multiple EVs.
Commercial buildings are a different calculation entirely. We size services based on connected load, demand factors, and planned expansion. Undersizing a commercial service means voltage drop, equipment damage, and expensive rework later. We always spec for 25% growth minimum.
Your panel isn't just a box of switches — it's a life-safety system. If you haven't had it inspected in the last 5 years, or if you're adding significant loads, you need a professional evaluation.
Schedule a Panel Inspection →