By Peter, Master Electrician | PRO Electric plus HVAC | Electrical Panel Upgrades
McLean 400 Amp Panel Upgrades | PRO Electric plus HVAC
I am Peter, Master Electrician at PRO Electric plus HVAC. In McLean, I see many beautiful homes that outgrew their original electrical service.
New additions, EV chargers, heated pools, home theaters, and smart systems all add load.
If your main panel is still 200A, you may be living right at the edge.
A 300A or 400A service with well-planned subpanels restores headroom, reliability, and safety.
Signs your main panel is underpowered
- Breakers trip during normal use or when multiple large appliances run together
- Lights dim or flicker when HVAC or pool pumps start
- Panel is full, tandem breakers everywhere, no space for new circuits
- Hot breaker faces or a humming main breaker
- EV charging or kitchen remodel forced you to “make do” with shared circuits
Why 300A to 400A service makes sense in McLean
High-end homes stack big loads. Common examples:
- Two to three HVAC systems, heat pumps, electric furnaces, or radiant heat
- Level 2 EV chargers for two vehicles
- Pool equipment, spas, saunas, exterior heating, and landscape lighting
- Chef kitchens with induction ranges, steam ovens, and built-in refrigeration
- Home theaters, server racks, and whole-home automation
Moving to 300A or 400A gives you future capacity, reduces nuisance trips, and protects sensitive electronics from voltage sag during large motor starts.
How I handle a service upgrade, step by step
- Load calculation and survey
I measure real usage, review appliance nameplates, and map every large load. - Utility and code coordination
I coordinate service lateral or drop sizing, meter base upgrades, and clearances with the utility. All work follows the current NEC and local amendments. - Scope and design
We decide between 320A continuous (400A class) service, a new main panel, and any subpanels. I plan feeder sizes, grounding, bonding, and equipment locations. - Permits and inspections
I pull the permits. Every panel and service upgrade is inspected. You get full documentation for insurance and resale. - Clean installation
I replace outdated gear, label every circuit, and balance loads across phases. I install whole-home surge protection and arc fault protection where required. - Commissioning
I verify torque, insulation resistance where needed, and voltage under load. You see the results before we sign off.
Smart use of subpanels for additions
Subpanels keep runs short, reduce voltage drop, and localize control.
Common McLean layouts I install
- Garage EV subpanel with dedicated 60A to 100A EV circuits
- Pool house subpanel for pumps, heaters, and lighting on GFCI protected feeders
- Guest suite or carriage house subpanel to isolate loads and simplify shutdown
- Theater or studio subpanel with isolated circuits for clean power
Design details that matter
- Correct feeder sizing with aluminum or copper, based on distance and load
- Four-wire feeders with isolated neutrals in subpanels, proper grounding and bonding
- Load balancing across A and B phases to reduce neutral current and lights dimming
- Clear labeling and spare capacity for future projects
Reliability and protection upgrades I recommend
- Whole-home surge protector at the main service to shield electronics
- AFCI and GFCI protection to meet code and reduce fire and shock risk
- Dedicated appliance circuits for kitchen, laundry, office, and gym equipment
- Generator or battery readiness with a listed transfer switch or inverter-ready layout
- Power quality monitoring to spot issues early and protect investments
When to call me
- You are planning an addition, pool, or second EV
- You have a Federal Pacific or Zinsco panel that insurers dislike
- Breakers trip under normal use or lights dim when HVAC starts
- You want room for future projects without tearing into the panel again
I will evaluate your load, design the right 300A or 400A service, and install clean subpanels that keep your home reliable and safe.
Call PRO Electric plus HVAC at 703-225-8222 to schedule an on-site assessment in McLean.
We pull permits for every service and panel job, meet inspection, and stand behind our work.
We also serve Fairfax County, Arlington County, Loudoun County, and Prince George’s County.
📞 Call 703-225-822 now or book online while you’re thinking about it.
