100, 150, or 200 Amp Service: Has Your Ann Arbor Home Outgrown Its Panel?

What 'Amp Service' Actually Means

Your home's amp service is the total amount of electrical current that can come into the house at once, sized by the main breaker, the panel, and the meter together. Common residential sizes are 100, 150, and 200 amps, and some older Ann Arbor homes started out even lower than that. Every circuit in the house, every outlet, every appliance, is drawing from that same shared ceiling.

Why 100 Amps Used to Be Plenty

Decades ago, a typical house didn't ask much of its panel. Fewer major appliances, no central air conditioning, none of the electronics load a modern home carries. A 100 amp panel handled that fine, and for a lot of smaller, older homes it still does. The trouble starts when a house keeps growing but the panel doesn't.

What Changed

• Central air conditioning
• An electric range or oven
• A finished basement or an addition, each adding new circuits
• An EV charger
• A hot tub or pool equipment
• A home office running more equipment than a single power strip

Each of those adds real, ongoing load. A 100 amp panel that was fine for the original house can end up stretched thin once several of these get added over the years, one at a time, without anyone stepping back to look at the total picture.

Signs Worth Paying Attention To

• Breakers that trip when two big appliances run at the same time, like central air and the dryer
• Lights that dim across the house when something large kicks on
• A panel that's already full, with no open slots for a new circuit
• An electrician telling you a new circuit isn't possible without a panel change
• An inspector or insurance company flagging an old fuse box or undersized service during a sale or refinance

A panel that's been added onto piecemeal over the years, with breakers doubled up in slots that were only ever meant to hold one, is its own warning sign even if nothing has tripped yet. That kind of crowding usually means the original service size was never revisited as the house's needs grew, and it's often easier to catch during a straightforward panel inspection than to wait for something to actually fail.

100 vs. 150 vs. 200 Amps

In broad terms, 100 amp service still covers a modest home without heavy electric loads. 150 amp gives some breathing room for a house that's grown over time. 200 amp is the standard most new construction and larger homes are built around today, especially anywhere central air, an electric range, and an EV charger might all be running at once. Which size is right for a specific house depends on what's actually running in it, not a general rule of thumb, so it's worth having someone look at the real load rather than guessing.

Bigger Isn't Automatically the Right Call

It's tempting to think more amps is always the safer choice, but a service upgrade is real work and real cost, and a 200 amp panel isn't automatically the right fit for a small house with modest electrical needs. The point of the upgrade is matching the service to what the house genuinely draws, now and for whatever's realistically coming in the next several years, not chasing the biggest number available. That's part of why an actual load assessment matters more than picking a size off a chart.

What a Service Change Involves, in Broad Strokes

A service upgrade generally means replacing the panel and main breaker, and often the meter socket and the wire feeding the house, all sized for the new amperage. It typically requires coordinating with the utility company to disconnect and reconnect power for the switch, and it needs to be inspected like any other electrical work. It isn't a same day swap of just the breaker box. The whole path from the street to the panel gets looked at, and every circuit already in the house gets reconnected into the new panel as part of the same job, not left hanging while only the box itself changes.

Getting an Honest Read on Your Panel

If your panel is already crowded, if you're planning an addition, an EV charger, or new kitchen appliances, or if you've just been quietly living with the same breaker tripping for years and calling it normal, it's worth having someone look at what your home is running against what the service can actually handle. Vedder Electric has been doing service panel upgrades in Ann Arbor for over 35 years, from 100 amp homes stepping up to 150, right up through full 200 amp service changes. Call 734-662-6220 and we'll take a look at your panel.