Chapter 26: Main Panel Replacement

This is the chapter where the soft pro-call nudge gets less soft. Replacing the main panel of a house involves work between your home and the utility's grid, on conductors that aren't fused (the line side of the meter is unfused service), with significant downside if anything goes wrong. We'll cover the project in enough detail that you can intelligently work with a contractor, but for most homeowners, this is the project to hire out.

That said: the work is doable, and there are circumstances where DIY makes sense (you have significant electrical experience, the panel is in an accessible location, you're prepared for the day-long no-power period). We'll walk through it honestly.

Estimated time: 1–2 days for a pro. 3–5 days for a homeowner doing it for the first time. Cost: $1,500–6,000 in materials. Pro install $3,000–14,000 total. Permit required: yes, in all jurisdictions. Often requires utility coordination too.

When You'd Replace a Main Panel

Several scenarios trigger this:

Service capacity is inadequate. Adding an EV charger, a heat pump, a workshop with serious tools, or whole-house solar plus battery often pushes a 100A or 150A service into "needs upgrade" territory.

Panel is unsafe. Federal Pacific Electric (FPE) Stab-Lok panels have a documented history of failing to trip during overloads, leading to fires. Zinsco panels (which became Sylvania-Zinsco, then GTE-Sylvania) have similar issues with breakers fusing in place. If you have one of these brands, replacement is recommended even without other reasons.

Panel is showing age. Panels manufactured in the 1960s–1980s using copper-coated aluminum bus bars, certain breakers, or pre-modern code interpretations may not meet current safety standards. Visible damage (rust, melting, burned breakers, evidence of overheating) is a clear signal.

Modernizing for a remodel or addition. Major remodels often require panel upgrades to support the new electrical loads.

Selling/refinancing. Some buyers and lenders require panel inspections or upgrades for older or problem panels.

Key Decisions Before Starting

Several decisions shape the project:

Service amperage. 100A, 200A, or larger? For OKC homes, 200A is the modern standard. 100A is barely adequate for a typical 1,500 sq ft home with normal modern appliances. 400A is occasionally seen for very large homes or those with significant electric load (heated pools, large workshops, high-end EV charging).

Indoor vs outdoor panel. Existing panel is usually in the same location as the new one, but if you're doing a major upgrade, sometimes moving the panel makes sense (better access, closer to high-load areas).

Brand and model. Square D QO and Square D Homeline (HOM), Eaton BR, and Siemens are the major modern brands. Each has tradeoffs:

The brand matters for breaker compatibility. Once you choose a panel, you're committed to that brand's breakers (no mixing brands within a panel).

Number of breaker spaces. A 200A panel typically has 30–42 spaces. Larger is better for future expansion. The price difference between a 30-space and 42-space panel is modest ($50–200); the value of having extra space later is significant.

Surge protection device (SPD). NEC 2023 requires whole-house surge protection for new dwelling unit panels. Plan for this. SPDs install in the panel and protect the whole house from voltage spikes.

The Utility Coordination

The main panel can't be replaced while the utility is feeding power into the service. The utility (OG&E in OKC) has to:

1. Pull the meter (disconnects the utility from your service entrance).
2. Allow you (or your contractor) to do the work without energized service.
3. Reconnect after inspection.

For a homeowner DIY:

1. Contact OG&E (or your specific utility) to schedule a service disconnect/reconnect.
2. Confirm timing: typically the disconnect happens in the morning, you (or contractor) do the work during the day, the utility reconnects in the afternoon or next day after inspection.
3. Plan for being without power that day. Move freezer/refrigerator items to a cooler. Charge devices. Skip cooking that day.

Some utilities prefer working with licensed contractors (who have established procedures and accounts), and may require slightly more lead time for homeowner-initiated disconnects. Plan 2–4 weeks ahead.

Materials for a 200A Panel Replacement

For a typical 200A panel replacement in OKC:

• 200A main panel (with 200A main breaker installed; often called "main breaker panel" or MBP)
• Service entrance cable (typically 4/0 aluminum or 2/0 copper) from meter to panel; usually 6–10 feet
• Grounding electrode conductor (4 AWG copper) from panel to ground rod system
• Two 8-foot ground rods, copper-clad steel
• Acorn clamps for ground rod connections
• New breakers to match all existing branch circuits
• Whole-house surge protective device (SPD) per NEC 2023
• Permit fees
• Utility coordination fees (sometimes)

Total materials: $1,000–5,000.

For a service upgrade (100A to 200A), additional costs:

• Larger meter base and conduit (often included)
• Possibly larger service entrance cable from utility connection
• Sometimes a new mast or weatherhead

Total: add $500–3,000 to the basic panel cost.

Procedure Overview (DIY, Conceptual)

Even though we're recommending pro install, here's the high-level procedure for understanding what's involved:

1. Pull permit. Required.
2. Coordinate with utility for service disconnect.
3. Day of disconnect: - Utility arrives, pulls meter. - You verify service is dead. - Remove old panel:
   • Disconnect all branch circuit cables (one at a time).
   • Remove the old panel from the wall.
   • Remove old service entrance cable from old panel.
   • Install new panel:
   • Mount new panel on wall.
   • Run new service entrance cable from meter base to new panel.
   • Connect cable to main breaker lugs.
   • Install ground rod system if not adequate.
   • Connect grounding electrode conductor.
   • Reconnect branch circuits:
   • Each existing branch circuit cable is reconnected to a new breaker in the new panel.
   • Verify wire size matches breaker size.
   • Update any breakers that were undersized in the old panel.
   • Install whole-house SPD.
   • Install dead front cover.
4. Inspection. Inspector verifies the work.
5. Utility reconnect. After inspection passes, utility reinstalls meter.
6. Test. Verify all circuits work.

Each step has details that take training and experience. The pro advantage is having done dozens of these and knowing exactly what each inspector expects.

Why It's Hard for DIYers

Specific reasons this project is harder than it looks:

Service entrance work. The cables from meter to panel are large and stiff. Bending and routing them takes practice. Connections at the main breaker need to be tight without being over-tight.

Time pressure. You have one day (typically) to complete the work between utility disconnect and reconnect. Mistakes that take hours to diagnose can stretch the project by days, leaving the house without power.

Compliance with current code. A new panel must meet current code, which means GFCI/AFCI protection on circuits that didn't previously have them, working space requirements, surge protection, and various other updates. The old panel's circuit count may have grown; the new panel needs to accommodate everything.

Inspection scrutiny. Panel inspections are typically more thorough than other electrical inspections. Inspectors look at connection torque, clearances, labeling, and many details that homeowners might overlook.

Utility coordination overhead. Working out the schedule, the procedures, and the responsibilities is itself a project. Pros do this routinely.

Risk of error. A miswired panel can damage equipment, start fires, or kill someone. The downside of mistakes here is severe.

Working with a Contractor

If you're hiring out:

Get multiple bids. 3 is good. Compare on:

• Total price (panel, labor, permit, utility coordination)
• Brand and model of panel offered
• Breaker brand for the new circuits
• Surge protection included or extra
• Warranty on workmanship

Verify licensing. Oklahoma requires electrical contractors to be licensed. Verify with the Construction Industries Board (cib.ok.gov).

Insurance. The contractor should carry general liability and workers' comp insurance. Ask for proof.

References. Ask for recent customer references. Call them. Ask about the install experience: timeline, quality, surprises.

Permits and inspections. Confirm the contractor pulls the permit and handles the inspection. A reputable contractor does this as a standard part of the job.

Written estimate. Get the estimate in writing, with specific itemization. Verbal estimates that change at completion are a red flag.

For OKC metro, typical pricing for a straightforward 100A to 200A panel upgrade:

• Pro install: $3,500–13,000 total
• Premium options (heavier panel, additional features): $6,500–18,000+

A homeowner who DIYs the work might save $1,000–4,000, but the project takes 5–10x as long.

After the Replacement

Once the new panel is in service:

Update your panel directory. Make sure all circuits are clearly labeled. Take photos of the panel interior with the cover off, for future reference.

Test circuits. Verify each circuit works. Test GFCIs and AFCIs. Plug in your tester at outlets to confirm proper wiring.

Document. Keep records of the new panel: brand, model, capacity, installation date, contractor name (if applicable), permit number, inspection record.

Future-proof note. A new 200A panel with 30–42 spaces is good for decades of typical residential use. If your future plans include adding solar, a heat pump, or significant additional load, the new panel is positioned to handle it. If you're in a home where you might add solar within the next 10 years, talk to your electrician about whether a "solar-ready" panel (with specific bus bar configurations and breaker space) is worth the marginal extra cost now.

When DIY Panel Replacement Makes Sense

A few scenarios where DIY is more reasonable:

• You're a licensed contractor or have professional electrical experience.
• The panel is in a basement or garage with excellent access and lighting.
• You have a confirmed multi-day window for the work, not a single-day pressure.
• Your jurisdiction has straightforward utility coordination procedures.
• You're going to have a peer (another experienced electrician, even unlicensed) help with the second pair of hands at critical points.

For most other situations, hiring out is the better path.