100 Amp to 200 Amp Upgrade: What It Means for Your Home
From Solana Electrical, AZ ROC #341966
The short answer
A 100 amp to 200 amp upgrade raises the amount of power your home can draw from the utility at one time. Many older West Valley homes were built with smaller services sized for the appliances of their day. An upgrade makes room for central AC, an EV charger, a spa or a kitchen remodel without overloading the panel.
What the amp rating means
Every home has an electrical service: the wires from the utility, the meter, and the main panel. The service has an amp rating, and the main breaker at the top of the panel shows it. A 100 amp service can safely deliver less total power at one time than a 200 amp service.
Think of it like the size of a water main. A small pipe works fine for a few faucets. Open every tap in the house at once and the pressure drops. Electricity works in a similar way, except that when a service is pushed too hard, breakers trip and parts can run hot.
Why many older homes have 100 amps
Homes in Sun City were built from 1960 into the late 1970s, and many other West Valley neighborhoods followed. At the time, a typical home had a range, a water heater, a few lamps and perhaps one window AC unit. A 100 amp service was common and often enough.
Homes today ask much more of the same service. Central AC, a second refrigerator in the garage, a microwave, a spa, a golf cart charger and now an EV charger all add load. The panel may also be an older brand that is hard to find parts for. Put those together and the original service can be stretched thin.
Signs you may have outgrown 100 amps
None of these alone proves you need an upgrade, but each is worth mentioning when you call.
Breakers that trip when the AC and another large appliance run together
Lights that dim when the AC, dryer or microwave starts
No open spaces left in the panel for a new circuit
Plans to add an EV charger, a spa, a workshop or a kitchen remodel
Many double-up or tandem breakers squeezed into the panel
An older panel brand such as Federal Pacific or Zinsco
What changes in a 200 amp upgrade
A service upgrade is more than a new panel. Depending on the home, it can include several parts of the system working together.
A new main panel with a 200 amp main breaker and room for more circuits
A new meter base, if the old one is not rated for the higher service
Larger service entrance wires from the meter to the panel
Updated grounding and bonding to meet current code
Coordination with the utility, which must disconnect and reconnect power
A permit and a final inspection before the utility restores service
Is 200 amps always the answer?
Not always. The right size comes from a load calculation, which adds up what your home uses and what you plan to add. Some homes do well with a panel replacement at the same size. Others need a larger service. A home that only wants a modest EV charger may need neither.
We would rather tell you that a smaller job will do than sell you a bigger one. If your home needs 200 amps, we will explain why in plain words. If it does not, we will say so.
How to check your service safely
Open only the outer panel door, the way you would to reset a breaker. Look at the large breaker at the top or in its own box near the meter. The number printed on its handle is usually your service size. You can also look for a label inside the door.
Do not remove the inner cover or touch anything behind it. Parts in there stay live even with the main breaker off. If the label is hard to read, take a photo from a safe distance and describe it to us on the phone.
What a larger service makes possible
A larger service does not change how your lights or outlets work day to day. What it changes is how much you can run at the same time without trouble. With more capacity and more breaker spaces, it becomes easier to add the things many homeowners want as their needs change.
A Level 2 EV charger or a dedicated golf cart circuit
A spa or hot tub
A workshop or hobby room in the garage
A second AC unit or a larger heat pump
Kitchen appliances such as an electric range or induction cooktop
A whole-home surge protector and room for future circuits
Questions to ask before you decide
Whoever you call, ask them to explain their load calculation, not only the size they recommend. Ask whether the meter base and service wires are included, who pulls the permit, and who coordinates with the utility. Ask what warranty covers the work. A clear answer to each one is a good sign that the job has been thought through.
Planning your upgrade with Solana Electrical
Call us at (602) 999-2770 and a real person answers. Tell us your current service size, what you want to add, and what you have noticed. We will tell you whether an upgrade looks likely and what the visit costs before anyone drives out.
Our electricians handle the permit, the utility coordination and the inspection. All of our labor and material carry a two-year warranty, and we are licensed under AZ ROC #341966.
A panel that feels hot, smells like burning or buzzes loudly should not wait for a planned upgrade. If you see smoke or fire, get out and call 911.
Common questions
Can I add an EV charger to a 100 amp service?
Sometimes. It depends on what else the home uses. A load calculation shows whether there is room, whether a smaller charger setting will work, or whether the service needs to grow.
Does a 200 amp upgrade need a permit?
Yes. A service upgrade requires a permit and an inspection, and the utility will not restore power until the work passes.
Will a 200 amp service raise my electric bill?
No. Your bill depends on how much power you use, not on the size of the service. A larger service only allows more power to be available when you need it.
