Do I Need an Electrical Panel Upgrade for a Generator?
Many East County homes built before 2000 have 100-amp electrical panels that can't support whole-house generators. Learn how to tell if you need an upgrade and what's involved in the process.
100-Amp vs 200-Amp Panels
| Feature | 100-Amp Panel | 200-Amp Panel |
|---|---|---|
| Maximum Load | 24,000 watts | 48,000 watts |
| Generator Compatible | Up to 13 kW | Up to 26 kW |
| EV Charger Ready | Usually no | Yes |
| Central AC Support | Limited (3 ton max) | Full (5+ ton) |
| Home Size | Under 2,000 sq ft | Any size |
| Modern Code | Grandfathered | Current standard |
Signs You Need a Panel Upgrade
Check for these indicators that your electrical panel needs upgrading before generator installation:
Why Generators Require 200-Amp Panels
A whole-house generator installation requires an automatic transfer switch that connects between your main panel and utility service. Here's why 200-amp service is typically required:
- •Transfer switch sizing: A 200-amp transfer switch is standard for whole-house coverage
- •Load calculations: Central AC + well pump + appliances often exceed 100-amp capacity
- •Code compliance: California Title 24 requires adequate service for all connected loads
- •Future-proofing: 200-amp supports EV chargers, additional AC units, shop equipment
Exception: Partial Coverage with 100-Amp Panels
If you only want essential coverage (lights, refrigerator, some outlets) and don't need to power central AC or large appliances, a smaller generator (10-13 kW) with a load-management transfer switch can work with existing 100-amp service. However, this limits your backup power capabilities during extended PSPS events.
Panel Upgrade Costs
Electrical panel upgrade costs in San Diego East County typically range from $2,500–$4,500 depending on several factors:
Cost Breakdown
- • 200-amp panel and breakers: $500–$800
- • 200-amp transfer switch: $800–$1,500
- • Labor (6-10 hours): $1,000–$1,500
- • SDG&E meter upgrade coordination: $200–$400
- • Permits and inspection: $200–$300
Total Range: $2,500–$4,500 (standalone upgrade)
When combined with generator installation, panel upgrade adds approximately $2,500–$3,500 to total project cost.
Panel Upgrade Process
When combining panel upgrade with generator installation, here's what to expect:
- 1Assessment: Evaluate current panel, load calculations, and generator requirements
- 2SDG&E Coordination: Arrange temporary disconnect and meter upgrade
- 3Permitting: Obtain electrical permit from San Diego County
- 4Panel Replacement: Install new 200-amp panel with all circuits (4-6 hours, power off)
- 5Transfer Switch: Install automatic transfer switch for generator
- 6Generator Install: Complete generator installation and connections
- 7Inspection: County electrical inspector approves all work
Combined panel upgrade + generator installation typically takes 2-3 days of on-site work after permits are approved. See our panel upgrade service page for more details.
Get Your Panel Evaluated
Our free on-site assessment includes complete electrical panel evaluation. We'll determine if your current panel supports your desired generator or if an upgrade is needed, and provide complete pricing for either scenario.