Chapter 32: Whole-House Issues

The first three chapters of Part VI dealt with problems on a single circuit: a tripped breaker, a flickering fixture, a dead outlet. Whole-house issues are different. The problem isn't one circuit, it's the service. Half the house dimmer than the other half. Lights that flicker when the AC kicks on. Voltage that's just plain wrong everywhere.

These are rarer than circuit-level problems but they're more serious. The problem is usually upstream of your panel: at the meter, at the service drop, or in the utility's transformer. Keep equipment assembled and report observations from normal use. The utility and a licensed electrician can determine which part of the system needs investigation; do not make live measurements to decide whom to call.

Let's go through them.

"Half the House Is Out" (the Lost-Leg Diagnosis)

A partial-house outage can suggest a supply or service problem, but the symptom alone does not establish the diagnosis. Note which rooms lost power and whether lights changed brightness, without resetting every protective device or opening equipment.

One possible cause is loss of a service leg. Your house gets 240V from the utility in the form of two 120V legs that are 180 degrees out of phase. The breakers in your panel alternate between the two legs (left side, breaker 1 is on Leg A, breaker 3 is on Leg A, breaker 5 is on Leg A, etc.). Half your circuits are on Leg A, half on Leg B. Lose one leg, and half your circuits go dead.

The lost leg can be:

• A bad main breaker. The two halves of the main breaker are mechanically linked but electrically separate. One half can fail while the other still works. This is the most common cause inside the house.
• A burned or loose connection at the panel. Where the service entrance cable lands on the main breaker, or at the meter base. Bad connections heat up, oxidize, and eventually open up.
• A failed connection at the meter. Either the meter's internal contacts (the meter is essentially a switch in line with one of the legs) or the connection between the meter and your panel.
• A broken wire in the service drop or service lateral. The wires from the utility transformer to your meter. This is on the utility side.
• A failed transformer tap. The connection at the utility transformer that feeds your house. Also utility side.

For a homeowner, the useful information is the pattern: which rooms lost power, when it started, and whether lights became unusually bright or dim. Do not pull a dead outlet, open a panel, or probe meter equipment to confirm a lost leg.

Contact the utility for a suspected supply outage or damaged service, and arrange a licensed electrician for house-side diagnosis. Report what you observed; the responsible professionals determine where the fault is. Keep away from damaged equipment and downed wires. For smoke or fire, leave and call 911.

"Lights Dim When the AC Kicks On"

This is one of the most-reported residential issues, especially in OKC's hot summers when AC compressors cycle constantly. There's a benign version and a serious version. Telling them apart matters.

Benign version: a quick, brief flicker the moment the compressor starts, then steady. This is normal. Compressors have a huge inrush current when they start (5–7x the running current). That inrush causes a momentary voltage drop on the service. Every house in your neighborhood does it a little. As long as the dim is brief and recovers fully, no action needed.

Serious version: the lights stay dim for a full second or more after the compressor starts, or they dim noticeably in rooms far from the AC. Or a flicker that's more pronounced over time. This points to a high-resistance connection somewhere on the service or in the panel. As current flows through the bad connection, voltage drops downstream, and lights dim more than they should.

The most common spot: the connection between the service entrance cable and the main breaker, or the connection between the main breaker and the bus bar. These are big terminals that carry full house current. They get hot when loaded, cool down when unloaded. Thermal cycling loosens them over decades. A loose main breaker connection is a known fire hazard.

Tell-tale signs that need immediate attention:

• The flicker is getting worse over time.
• You smell anything from the panel (burning, ozone, hot plastic).
• The panel cover is warm to the touch.
• Lights become unusually bright or dim across different parts of the house.

The Neutral-Side Equivalent

Just like you can lose a hot leg, you can lose your neutral. We touched on this in Chapter 30, but it's worth covering again because it's the single most damaging electrical fault that can happen to a house.

A failed service neutral lets the voltage on each leg float. One leg might surge to 150–180V. The other might drop to 60–80V. Devices on the high-voltage leg fry. Devices on the low-voltage leg run hot or fail to operate. LED bulbs strobe. TVs die instantly. Refrigerator compressors burn out. The damage can be catastrophic and almost instantaneous.

Symptoms (often appearing together):

• Lights brighten in one part of the house when something turns on elsewhere.
• Lights dim in another part of the house at the same time.
• Multiple electronic devices have failed in a short period.
• Some appliances run weak (microwave seems slow, AC compressor labors).
• Several rooms show unusual brightness changes or unexpected appliance behavior.

Utility-Side vs House-Side: The Decision

You do not need a live voltage measurement to report a suspected service problem. Contact the utility for an outage, damaged service connection, or downed wires. Contact a licensed electrician for damaged house equipment, recurring trips, or unexplained electrical behavior.

The utility and electrician establish whether the fault is on their equipment and coordinate any needed isolation. Keep covers in place. Do not inspect meter connections or panel terminals yourself, and do not rely on this guide for utility response-time or cost promises.

Surge Damage and How to Prove It

Lightning strikes are common in Oklahoma summers. Direct strikes are rare, but indirect strikes (lightning hits a power line a mile away, the surge travels down to your house) happen multiple times per year for many homeowners.

Symptoms of a recent surge event:

• Multiple electronics dead at once (TV, modem, microwave, garage door opener, all at the same time).
• A breaker that won't reset, on a circuit that has surge-sensitive equipment.
• A burned smell at one or more outlets.
• A whole-house surge protector (if installed) showing a tripped or failed indicator.

If you suspect surge damage:

1. Document everything with photos before you start replacing things. Insurance adjusters will want to see the failed equipment.
2. Note the date and time. Cross-reference with weather radar. National Weather Service archives storm reports for OKC.
3. Check whether your house has a whole-house surge protector. If it does and it's tripped, that's good evidence of a surge event. If it doesn't, this is a great time to install one (typical cost runs $400–800 installed at the panel).
4. Call your insurance company. Surge damage from lightning is usually covered under homeowners insurance, with a deductible. Most insurers have specific surge claim procedures.

A whole-house surge protector at the panel is one of the cheapest insurance policies you can install. We do these all the time, and they save lots of households from exactly this kind of damage. If you don't have one, this is a good upgrade to ask about.

When the Whole House Is Acting Weird and You Can't Pin It Down

Sometimes you get a problem that defies simple categorization. Random circuits act up at random times. Devices fail mysteriously. Nothing matches a clean pattern.

For these cases, the diagnostic effort is more than a weekend project. We use power-quality recorders, infrared imaging at the panel, and historical voltage logging to find subtle problems that homeowners can't see with a basic meter. A power-quality study runs a few hundred dollars but can identify problems that have stumped homeowners for months.

If your house is acting strange in ways you can't explain, get a professional diagnosis. The cost of one service call is much less than the cost of replacing a dishwasher or AC unit that died because of an underlying electrical fault.

That's the end of Part VI. You now have a structured way to approach any residential electrical problem: gather information, isolate the failure, work the patterns, and know when to escalate. Use it.

The previous six parts of this book walked through how electrical systems work, how to plan and run circuits, how to install and modify equipment, and how to troubleshoot when something goes wrong. The chapters were meant to be read in order, at least the first time through.

Part VII is different. These are the chapters you'll come back to, not to learn something new, but to look something up. The wire size for a 20-amp circuit running 80 feet. The minimum box volume for three 12 AWG conductors plus a device. The clearance you need in front of a panel. The word for that thing your inspector said your neutral bar was missing.

The format reflects that. Most of these chapters are mostly tables, with just enough narrative to tell you how to use them. They're meant to be flipped to, not read straight through.

The last chapter, Chapter 37, is different again. It's the only chapter in Part VII that's more narrative than table. It's an honest accounting of which jobs are worth doing yourself and which aren't, and how to tell the difference. Read it once, then come back to it whenever you're standing in front of a project trying to decide.