Commercial Electrical Services · Pillar Guide
Three-phase service upgrades, 400-800A panel replacements, and the after-hours coordination that keeps your retail/restaurant/office running during the install.
Commercial panel work differs from residential in three ways. First, the service is almost always three-phase (208V or 480V) rather than single-phase 240V — different equipment, different code requirements, different installer competency. Second, the amperage is larger — 400A and 600A panels are typical, with 800A for larger restaurants and small industrial. Third, the scheduling constraint is business continuity — most installs happen overnight or over weekends.
The biggest preventable issue on commercial panel work is mismatched scheduling between contractor, PG&E, and the business operator. PG&E commercial dispatch books 4-8 weeks out; the contractor needs to align that with the business's operational schedule (slowest day of week, between rush seasons, around lease coordination). We do this scheduling math at quote time, not at install time.
A commercial panel upgrade replaces or expands the main electrical service to a business property — typically three-phase 208V or 480V, larger amperage than residential, with PG&E service-side coordination on a commercial dispatch timeline.
Most retail, office, and small restaurant buildings run 208V three-phase. Heavy equipment users (commercial kitchens with electric ranges, manufacturing, warehouse HVAC) often run 480V three-phase. The service voltage determines panel type, breaker stock, and conductor sizing — not interchangeable mid-project.
Most Marin commercial panel work happens overnight (10pm-6am) or weekend (Saturday morning) to avoid daytime business disruption. We coordinate with PG&E commercial dispatch for off-hours service interruption, stage materials on-site the prior business day, and run the install with the business closed.
For the broader context this guide supports, see our Commercial Electrical Services overview.
Commercial panel work clusters around service-side scope, panel sizing, brand selection, and after-hours scheduling. This pillar links to the specific guides.
Three guides to read first
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Commercial pricing varies more than residential because scope variables (service voltage, panel amperage, after-hours premium, PG&E coordination complexity) have wider spread.
| Project | Typical Marin range | Drives variance |
|---|---|---|
| 400A 208V/3-phase commercial panel | $11,000 to $18,000 | Conduit run length, after-hours |
| 600A 208V/3-phase commercial panel | $16,500 to $26,000 | Service-drop work needed |
| 800A 208V/3-phase commercial panel | $24,000 to $38,000 | PG&E coordination, transformer |
| 400A 480V/3-phase service upgrade | $18,000 to $32,000 | Transformer requirements |
| After-hours premium (typical scope) | +15-25% | Overnight vs weekend rates |
| Tenant improvement panel work | $4,500 to $14,000 | Existing service, suite scope |
Most Marin commercial panel work happens overnight or over weekends. Here's why and how the scheduling actually works.
Mill Valley restaurant client needs panel upgrade to support new kitchen equipment. Daytime install means 8-hour business closure during peak revenue hours — roughly $4,800-$8,000 lost revenue per day. After-hours install eliminates the revenue loss.
We coordinate three parties: PG&E commercial dispatch (for the overnight service interruption window, booked 4-8 weeks out), the business operator (for closing-time access and re-opening readiness), and the inspector (for early-morning sign-off so the business can open on time).
Final outcome: 8 hours of overnight install (10pm-6am), inspection at 7am, business opens normal hours at 11am. After-hours premium ($1,500-$3,500 typical) is much cheaper than lost revenue from a daytime install.
Commercial panel work uses three-phase power instead of single-phase residential. The differences matter for equipment compatibility, installer competency, and code requirements.
Standard for retail, office, restaurants, small mixed-use. Provides 120V for general loads and 208V for equipment. Most C-10 contractors can work it; the panel and breaker stock is different from residential 240V.
Used in larger restaurants with electric kitchens, warehouses with industrial HVAC, manufacturing. Provides 277V and 480V — incompatible with residential equipment without transformers. Requires C-10 with documented 480V experience; not all qualify.
Commercial quotes have more variables than residential. Three things to verify on every quote.
Ask for two recent commercial three-phase references the contractor can name. Three-phase is its own discipline; residential-only contractors quoting commercial work is a real category of bad outcomes.
Quote should explicitly itemize after-hours premium separately from base labor rate. 'All-inclusive' commercial quotes that bury after-hours pricing make it impossible to compare across bids.
This guide reflects Towery Electric's professional standards as a California-licensed C-10 electrical contractor and is for general information. Site conditions, panel configurations, code amendments, and permit-authority requirements vary; final scoping, sizing, and code compliance for your specific address are determined on a paid site assessment. We follow California Electrical Code (Title 24, Part 3) and applicable NFPA 70 (NEC) editions adopted by your AHJ.
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