How can I tell what size electrical service my home has?
The main breaker at the top of your panel is usually labeled with the service size, such as 100, 150 or 200. The label is a good starting point, but the meter base, service wires and panel itself must also be rated for that amount, and only a licensed electrician should confirm it.
Looking at the label is safe. Opening the panel cover or touching anything inside is not, and you should leave that to a professional. Panels carry live parts even with the main breaker switched off.
Older homes in the West Valley, especially ones built before central air was common, often started with smaller service and were never enlarged to match added equipment.
Service size is only part of the picture. The meter, the wires from the utility, the panel and the breakers all have ratings, and the weakest piece limits the whole system.
What are the signs my home has outgrown its electrical service?
Signs your home has outgrown its service include breakers that trip often, lights that dim when the AC starts, no open slots for new circuits, and extension cords doing permanent work. Any of these can also point to a wiring fault, so they deserve a professional look.
Arizona summer is when a stressed service shows itself. The air conditioner runs for hours, a pool pump may add to it, and every other household load stacks on top.
If you notice a burning smell, a warm or buzzing panel, sparking, or a breaker that trips again right after resetting, stop using the affected circuits and call a licensed electrician right away.
Houses with a pool, a workshop or a casita often add loads one at a time. Each addition seems small until they all run on a hot afternoon.
What is an electrical load calculation?
An electrical load calculation is a method electricians use to add up the demand of your home's lights, outlets, appliances and major equipment, then compare the total to the service size. It shows whether the service is adequate and how much room remains for future additions.
The calculation counts square footage, large fixed appliances, the air conditioning, and planned additions such as a charger or a spa. It replaces guessing with a documented number you can use when deciding.
It also helps you avoid buying more service than needed. Some homes do well with a modest change, while others truly need a full service upgrade.
Ask the electrician to explain the result in plain terms and show the numbers. You should understand why they recommend what they do before agreeing to any work.
Does adding an EV charger or a new AC mean I need 200 amp service?
Adding an EV charger or a new AC does not automatically mean you need 200 amp service. It depends on what the home already draws and what the new equipment adds. A load calculation answers it, and many homes can add one large load without changing service size.
Smart load management devices can sometimes let a charger share capacity with other loads. Whether that is appropriate depends on your panel and local code, so ask the electrician about it.
Planning ahead is cheaper than redoing work. If you expect to add a charger, a pool or a bigger AC soon, have the load calculation done with all of them included. Vortech's licensed electricians can run the load calculation and explain the results before any panel work is proposed.
More questions: Electrical Panel Upgrades: 12 Most Asked Questions Answered