A new refrigerator, a built-in microwave, a second freezer in the garage, a wine cooler, a window air conditioner: before it arrives, it is worth asking whether the outlet it will plug into can carry it. Many of the tripping breakers we are called about started the week a new appliance went in. The answer depends on two things: what the electrical code requires for that room, and what the appliance's installation instructions call for.
What a dedicated circuit is
A dedicated circuit, sometimes called an individual branch circuit, is a circuit that runs from the panel to one outlet for one appliance, with nothing else on it. The appliance gets the full capacity of the circuit, and if it trips, nothing else goes out with it.
Start with the installation instructions
The National Electrical Code (NFPA 70), which Florida enforces through its building code, requires listed equipment to be installed according to its instructions. So if the manual for a built-in microwave, dishwasher or disposal says it needs its own 15 or 20 amp circuit, that is the requirement. Look in the installation guide, not the user manual, under electrical requirements. It usually gives the circuit size and whether the appliance must be on a circuit by itself.
Appliances that commonly need their own circuit
- Built-in and over-the-range microwaves. Most installation guides call for their own circuit.
- Dishwashers and disposals. Often on their own circuits, or a shared circuit where the instructions allow it.
- Electric ranges, cooktops, wall ovens, dryers and water heaters. These are 240-volt appliances on their own circuits, sized to the appliance.
- Window and through-the-wall air conditioners. Larger units in particular.
- Garage freezers and second refrigerators. Not always required, but a freezer sharing a garage circuit with tools and a GFCI that trips is a common way to lose a freezer full of food.
- EV chargers, pool pumps and spa equipment. Always on their own circuits. See whether your panel has room for an EV charger.
What about the refrigerator?
In kitchens, the code requires at least two 20-amp small-appliance circuits for the countertop outlets and the refrigerator, and allows the refrigerator outlet to be on its own individual circuit instead. Whether yours is on a shared or individual circuit depends on how the house was wired. A refrigerator on a shared kitchen circuit usually works fine; the trouble starts when the same circuit also carries the toaster oven, kettle and coffee maker at breakfast. If the kitchen breaker trips in the morning, that is the pattern.
Signs your current outlet is not enough
- The breaker trips when the new appliance and something else run together.
- Lights dim on that circuit when the appliance starts.
- The outlet or plug feels warm; see warm outlets.
- You need an extension cord or a power strip to reach the appliance.
- The outlet is two-prong, with no ground; see two-prong outlets.
Does the panel have room?
A new circuit needs a free space in the panel and enough capacity in the service for the extra load. Many older Miami panels are full or close to it. If there is no room, the options include a tandem breaker where the panel is listed for it, rearranging circuits, a subpanel, or a panel upgrade. See panel upgrades and signs a panel needs replacing.
What we do
Send us the appliance model or the electrical section of its installation guide. We will check the existing circuit, the panel and the route to the appliance location, and tell you whether it can share a circuit or needs its own. Adding a circuit usually needs a permit, which we handle. Our dedicated circuits page explains how we size circuits to equipment.
Questions people ask
Can I plug the new appliance into a power strip?
Not for refrigerators, freezers, microwaves, air conditioners or heaters. Plug them directly into a wall outlet that is suited to them.
My new appliance keeps tripping the breaker. Is it faulty?
Possibly, but usually the circuit is shared. Try it with nothing else on that circuit. If it still trips, the appliance or the circuit should be checked. See breakers that trip overnight.
Remodels and appliance swaps
Kitchen remodels are where circuit questions come up most. A remodel often adds a built-in microwave, a second oven, an under-counter refrigerator or a larger range, while the circuits stay the ones the house was built with. Planning circuits at the design stage, before cabinets and countertops go in, is far easier than adding them afterward. The same applies when a gas appliance is replaced with an electric one: an electric range, cooktop or dryer needs a 240-volt circuit sized to it, which the old gas location will not have.
For a straight swap, such as an old refrigerator for a new one, the existing outlet is usually fine if the old appliance ran without trouble. Check the new model's electrical requirements anyway, because larger units and units with ice makers and extra features can draw more.
Need it looked at?
KRW Electric (EC13012832) troubleshoots and repairs circuits for new appliances in Pinecrest, Coconut Grove, South Miami and Miami Beach, with same-day service when scheduling permits. Call (305) 359-7312 and tell us what you are seeing. We will ask a few questions, tell you whether it sounds urgent, and give you the earliest time we have. Our before you call checklist covers what to have ready, and what happens on a repair visit explains the rest.
Reviewed by Kyle White, KRW Electric Company LLC — licensed electrical contractor EC13012832.
