100-Amp Electrical Service in Chicago

Chicago homeowners typically call us about 100-amp service in three scenarios: the existing panel is failing, the service is undersized for current loads, or a new 100-amp service is being installed in a rental unit, garage, or coach house.

• Frequent breaker trips when the HVAC, dryer, and microwave run at the same time
• Flickering lights when the central AC compressor kicks on during a July heat wave
• Slow appliance operation — dryers that take two cycles, ovens that can't hold temperature
• No room for new circuits — the panel is full and every breaker is already double-tapped
• Aging service older than 25 years, especially Federal Pacific Stab-Lok, Zinsco, or Pushmatic panels
• Adding high-demand features like a hot tub, Level 2 EV charger, or ductless mini-split

If you live in a Chicago bungalow, two-flat, or vintage three-flat, your 100-amp service was likely sized for 1970s appliance loads. Modern life asks much more of it. Many homeowners in Portage Park, Chatham, Bridgeport, and Auburn Gresham are discovering that their 100-amp service no longer has the headroom it once did.

Whether we're installing a new 100-amp service for an ADU or upgrading a failing 60-amp service to 100 amps, the scope typically includes:

• Coordination with ComEd for the service disconnect and reconnect
• New service entrance cable from the weatherhead to the meter
• New meter socket that meets current ComEd specifications
• New 100-amp main breaker panel with adequate circuit capacity
• Grounding electrode system (ground rods, water pipe bond) per Chicago Electrical Code
• Bonding of gas lines, CSST where applicable, and metal water piping
• All permits pulled through the Chicago Department of Buildings
• Final electrical inspection and utility release

A straightforward 100-amp service upgrade in an owner-occupied Chicago home is usually a one- to two-day project, depending on how far the meter sits from the panel and whether the existing service entrance conduit can be reused.

100-amp service is sufficient for many older homes with gas appliances and modest electrical loads. But if you're planning any of the following, we'll usually recommend going straight to 200 amps instead of replacing like-for-like:

• A future [EV charger installation](/services/chicago/ev-charger-installation-chicago)
• A [kitchen electrical remodel](/services/chicago/kitchen-electrical-remodel-chicago) with induction cooking
• Whole-home rewiring or a [home rewiring project](/services/chicago/home-rewiring-chicago)
• Converting a gas furnace to a heat pump
• A [basement electrical wiring](/services/chicago/basement-electrical-wiring-chicago) project with a new living suite

The material cost difference between 100-amp and 200-amp equipment is modest. The labor and permit work is nearly identical. Most homeowners who upgrade to 200 amps do so once and never think about it again. See our [electrical panel upgrade guide](/services/chicago/electrical-panel-upgrade-chicago) and [panel upgrade cost guide](/services/chicago/cost-guides/cost-panel-upgrade-chicago) for a detailed breakdown.

[Get a Free Estimate] | [Call Now: (312) 219-3386]