- Generator Installation Milwaukee & Southeastern WI
Generator Installation Milwaukee: Backup Power for Your Home
Stay powered through every storm with expert whole home generator installation from Lehmann Electrical & Design.
- Generac Installers
- Transfer-Switch Experts
- 12-Month Labor Guarantee
Call our licensed electricians
414-404-6900
Backup-Power Specialists
Standby & portable
Transfer-Switch Experts
Manual & automatic
Generac Installers
Guardian series
Licensed Electrician in Wisconsin
Master electricians
12-Month Labor Guarantee
On every install
1 Year of Service Included
With your generator
Stay Powered Through Every Storm
Serving Milwaukee and all of Wisconsin, our master electricians ensure your home or business never skips a beat, no matter the weather. From summer storms to winter freezes, we deliver reliable, code-compliant generator solutions that keep the lights on and life running smoothly.
Why Generator Installation Is Essential
A backup generator protects your home the moment the power goes out.
- Prevent food spoilage during outages
- Maintain critical home systems
- Ensure family safety during emergencies
- Avoid costly property damage
Generator Installation Options We Offer
Standby or portable: we install the right backup power solution for your home and budget.
Our master electricians provide on-site assessments. Mon to Fri, 8 AM to 5 PM.
414-404-6900
Whole-home backupStandby Generators
Permanent whole-home solutions that automatically activate during power interruptions. Perfect for:
- Homes with medical equipment
- Remote workers
- Families needing continuous power
- Properties in storm-prone areas
- Automatic power switching
- Seamless electrical integration
- Comprehensive home protection
- Increased property value
Portable backupPortable Generators
Flexible power solutions ideal for:
- Emergency backup
- Outdoor events
- Camping and recreation
- Temporary power needs
- Lower initial investment
- Easy storage
- Movable between locations
- Quick deployment
Choose Your Generac Generator Package
Professional installation by Wisconsin master electricians • Full permits & inspections included • 12-month labor guarantee
Budget Friendly
50A Portable Generator
Manual Transfer Switch • Natural Gas or LP
$3,000+
Starting Investment • Manual Operation
Powers Your Essentials:
- Refrigerator & freezer (save food)
- Sump pump (basement protection)
- Essential lights & outlets
- Basic heating system
- Occasional use appliances
Best For: Budget-conscious homeowners, occasional outages, basic essentials only. Requires manual startup and fueling.
Automatic Starter
7.5kW Guardian
Automatic Transfer Switch • Compact Design
$8,000+
Starting Investment • Automatic Operation
Powers Essentials + Comfort:
- All essentials (auto-start)
- Select comfort items
- Small HVAC systems
- Home office equipment
- No extension cords needed
Best For: Small homes or essential-only coverage with automatic convenience. Compact and efficient for smaller electrical demands.
Balanced Choice
10kW Guardian
Automatic Transfer • Medium Home Coverage
$11,000+
Starting Investment • Mid-Range Coverage
Powers More Comfort Needs:
- Essentials + HVAC (size dependent)
- Well pumps & more lighting
- Home office & electronics
- Kitchen appliances (limited)
- Moderate electrical demand
Best For: Medium homes with more comfort needs. Perfect balance of performance and cost for families working from home.
Most Popular Choice
18kW Guardian
Whole Home Protection • Model 7226/7228 • 100A Service Homes
$14,000+
Starting Investment • True Whole-Home Backup
Powers Most/All of Your Home:
- Run HVAC + kitchen appliances
- All electronics simultaneously
- Multiple circuits & lighting
- Garage doors & security systems
- Excellent long-term reliability
Best For: Standard Wisconsin homes with 100A electrical services. Handles higher loads smoothly with dependable whole-house backup.
⭐ A popular choice for dependable backup
Premium Power
22kW Guardian
Model 7043 • 200A Service Homes
$15,500+
Starting Investment • High-Output System
Power Like Normal Experience:
- Multiple HVAC units
- Electric ranges & high-end appliances
- EV chargers & workshop equipment
- Pool equipment & outdoor features
- Minimal load management needed
Best For: Larger homes with higher electrical demand and 200A services. Ideal for comfort-focused households with multiple systems.
Maximum Coverage
24kW Guardian
Model 7210 • Zero Compromises
$16,500+
Starting Investment • Maximum Protection
Power Virtually Everything:
- Large/luxury homes coverage
- Multiple HVAC, pools, spas
- All high-draw appliances
- Workshop & outdoor equipment
- Minimal/no load shedding
Best For: Maximum coverage for premium performance with 200A services. Top-tier whole-home protection with zero compromises.
Still Not Sure Which Size?
Our master electricians provide on-site assessments to recommend the perfect generator size based on your electrical panel, loads, and budget. No overselling, no guessing, just honest recommendations.
How We Size Your Generator
Generator sizing isn’t about square footage, it’s about electrical load. We run a full load calculation based on your home’s panel, connected appliances, and which circuits you want backed up.
Here's what we factor in:
AC compressor, well pump, sump pump
Refrigeration, lights
Do you need the guest bedroom, or just the essentials?
LP delivers slightly less output, which affects sizing
What we see most often: Homes think they need a 24kW, but after load calculation, a 22kW covers everything they actually care about. Or they assume 18kW is enough, then realize they want AC in July. That’s why we measure first.
We also check for load management options. Generac’s load-shedding modules can temporarily pause lower-priority circuits (like an electric water heater) during peak demand, allowing you to use a smaller generator.
Quick Sizing Guide
Typical Milwaukee-area home loads
Refrigerator, freezer, sump pump, essential lights, basic outlets, portable heater (manual operation required)
Above + small furnace, garage door, home office equipment, select comfort items (automatic operation)
Above + small HVAC system, well pump, more lighting circuits, kitchen appliances (limited), moderate electrical demand
Above + larger HVAC system, multiple rooms, full garage, window AC units, most home circuits simultaneously
Above + central air (up to 3-ton), washer, microwave, multiple rooms, home office, minimal load management
Above + electric water heater, full kitchen (range/oven), basement circuits, whole-house comfort, zero load shedding
Note: Actual coverage depends on your specific panel loads. Central air tonnage and electric vs. gas appliances make the biggest difference.
12012 W Fairview Ave · Get directions
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Review Proven
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BBB Rated
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Craft Warranty
Why Choose Lehmann Electrical for Your Generator Install
Trust Milwaukee’s backup-power specialists for your generator installation. Licensed Wisconsin electricians, Generac installers and a 12-month labor guarantee on every install.
Hear From Your Neighbors in Milwaukee & Waukesha
EXCELLENT Based on 519 reviews Posted on Google Cubby’s Reviews Had my breaker replaced same day as request for service. they were in and out quickly, and the amount due was very fair. I am going to set up a future appointment to have the complete electrical box replaced. Jordan communicated effectively and efficiently. Update 10/15/2026: Travis from LEHMANN electrical and design completed installing 4 gfci outlets and installed a CSST bonding for my gas line. He communicated throughout the process and did outstanding work. Do yourself a favor and contact LEHMANN if you need any electrical work completed they’re honest, their pricing is fair,and they always give you an estimate before they start work.Posted on Google Linda Sumwalt 16 year old solar panel removal from a barn roof.Posted on Google Verneesha Banks The guys from Lehman were great! They were very knowledgeable and informative. Answered my questions and went Above and Beyond to get things done.!Posted on Google Sally Shoemaker Great workers!Posted on Google Alicia Allison Travis did a great job, was VERY knowledgeable and kind, answered all my questions and more. Will be using LED again. Really like that they don't charge for estimates. Fair pricingPosted on Google Chris Cullen Fantastic service and communication. Highly recommend!Posted on Google Ed Chaltry We worked with Travis. From the moment he came out to give the estimate, he was very professional and able to answer our questions and provide the detail we needed to move forward. The installation itself was quick and of high-quality. I highly recommend Lehmann. Thank you!Posted on Google Renee Schultz Andy and Joe were so kind and professional. Andy offered fair pricing, and tried to repair my electrical issue using the most cost-effective solution. Would highly recommend Lehmann Electrical and Design!Posted on Google Sandy S I’d like to highly recommend Lehmann Electrical and Design. Recently my kitchen lost all power due to an overheating outlet. After calling several companies who were scheduling a week out for appointments, I called Lehmann and they came out the next day. Not only were their technicians, Alex and Travis, a pleasure to work with, they didn’t come in with a standard, by the book, approach. They thoughtfully considered and explained the options for fixing the problem, with safety being the number one priority. Lehmann will be my only choice for any future electrical needs.Posted on Google Krista Had a panel upgrade, fan installation, and some outlets relocated and added. I couldn’t be happier with Cavin and Team at Lehmann Electric! They were courteous, flexible, and knowledgeable; willing to answer any and all questions. Everything looks and works great!Verified by TrustindexTrustindex verified badge is the Universal Symbol of Trust. Only the greatest companies can get the verified badge who has a review score above 4.5, based on customer reviews over the past 12 months. Read more
Our Professional Installation Process
Step 1 starts with a quick call or quote request.
Mon to Fri, 8 AM to 5 PM · Wauwatosa office
Our Generator Installation Experts Proudly Serve
We serve homeowners and businesses across Southeastern Wisconsin, including:
Generator installation near you in Milwaukee & Waukesha County
Choose your city to see local services, or visit our office.
Mon to Fri, 8:00 AM to 5:00 PM · Sat & Sun: Closed
Frequently Asked Questions About Generator Installation in Milwaukee & Waukesha County
Get straight answers from licensed Wisconsin electricians about backup generator costs, permits, installation timelines, and more.
Generator installation costs depend on the system type and your property's specific requirements.
Portable generator setup with manual transfer switch: Starting around $3,000. Includes the transfer switch, professional installation, and safe hookup to your electrical system.
Automatic standby generators (complete installed pricing):
- 7.5kW Generac Guardian: Starting at $8,000
- 10kW Generac Guardian: Starting at $11,000
- 18kW Generac Guardian (most popular): Starting at $14,000
- 22kW Generac Guardian: Starting at $15,500
- 24kW Generac Guardian (maximum coverage): Starting at $16,500
These prices include the generator unit, automatic transfer switch, installation labor, permits, and standard site preparation. Additional costs may apply if your project requires gas line upgrades, electrical panel modifications, extended concrete pads, or unique site conditions.
Best approach: Schedule an on-site assessment where we evaluate your electrical panel, gas line access, and installation location to provide an accurate written quote.
Yes, generator installations require permits in Milwaukee and Waukesha County. An electrical permit is mandatory for all transfer switch installations and electrical connections to your main panel.
If the installation involves new gas line work or modifications to existing gas supply lines, a separate gas permit is also required. The specific permits needed depend on your installation scope.
We handle the entire permitting process: Our service includes all permit applications, filing with municipal building departments, inspector coordination, and ensuring your installation passes final inspection. You don't visit city offices or take time off work for inspections; we manage everything from start to finish.
Installation day typically takes 6-10 hours depending on system complexity and site conditions. However, the complete process from consultation to operational generator averages 3-6 weeks.
Typical project timeline breakdown:
- Site assessment and quote: Same day or next business day
- Permit approval: 1-3 weeks (varies by municipality and season)
- Equipment delivery: 1-2 weeks (faster if in stock locally)
- Installation day: 6-10 hours
- Final inspection: Scheduled within 3-5 business days post-installation
Factors that accelerate timeline: Existing gas line near installation site, electrical panel in good condition, equipment in stock, fast permit processing.
Factors that may extend timeline: Electrical panel upgrades, extensive gas line modifications, concrete pad curing time, permit delays during peak seasons (spring and fall).
Generator sizing depends on your home's electrical load, circuits you want powered, and whether you need whole-home or essential-only coverage.
7.5kW Generac Guardian ($8,000+): Powers essential circuits automatically: refrigerator, sump pump, furnace, select lights and outlets, home office equipment. Best for smaller homes or critical-circuits-only coverage.
10kW Generac Guardian ($11,000+): Essential circuits plus HVAC (size dependent), well pump, additional lighting circuits, home office, some kitchen appliances. Best for medium homes and work-from-home families.
18kW Generac Guardian ($14,000+), Most Popular: Powers most or all of typical homes with 100-150A electrical service. Runs HVAC, all kitchen appliances, lights, electronics, garage door, everything simultaneously. Best for standard homes wanting true whole-house backup without load management.
22kW Generac Guardian ($15,500+): High-output system for larger homes with 200A service. Powers multiple HVAC units, electric ranges, Level 2 EV chargers, workshop tools, hot tubs, all appliances with minimal load shedding. Best for larger homes with higher electrical demand.
24kW Generac Guardian ($16,500+): Maximum residential capacity. Powers entire home simultaneously with zero compromises: multiple HVAC zones, pools, spas, all high-draw appliances, no load management required. Best for large or luxury homes.
Accurate sizing requires professional load calculation: We analyze your electrical panel, current usage patterns, and circuits you want covered to recommend the optimal generator size, not oversized for profit, not undersized to cut corners.
Whole-house coverage depends on generator capacity and your home's electrical requirements.
7.5kW-10kW systems power critical circuits: lights, refrigerator, furnace, sump pump, select outlets. Central air and high-draw appliances like electric ranges can't run simultaneously. Selective circuit management required.
18kW systems power most homes completely, which makes them our most popular choice. Central air conditioning, all kitchen appliances, lights, TVs, computers, entertainment systems run simultaneously like normal. Ideal for typical Milwaukee and Waukesha County homes with 100-150A electrical service.
22kW and 24kW systems eliminate load management concerns entirely. Designed for larger homes with heavy electrical loads, multiple HVAC systems, or high-draw equipment. Power everything simultaneously as if the grid never failed.
During your site assessment, we walk through your electrical panel and explain exactly what each generator size would power in your specific home, taking the guesswork out of your decision.
Most Generac Guardian generators operate on either natural gas or propane. We configure your system based on available fuel sources and property requirements.
Natural gas installations: If your home has natural gas service, this is typically the most convenient option. We connect to your existing gas supply (with line sizing upgrades if needed for generator demand). Benefits include unlimited fuel supply during extended outages, no tank refills, lower per-hour fuel costs, and no on-site fuel storage requirements. As long as utility gas lines remain operational, your generator has continuous fuel access.
Propane installations: For homes without natural gas access or in rural areas, propane provides reliable backup power independence. Installation includes on-site propane tank (typically 250-500 gallons for residential applications) and fuel line routing to the generator. Benefits include fuel independence from utility infrastructure, higher BTU content per gallon, and availability anywhere regardless of gas line access.
Both fuel types deliver reliable performance. Natural gas offers convenience if already available at your property. Propane provides energy independence and works universally regardless of location or utility service availability.
Transfer switches differ significantly in operation method and convenience level.
Manual transfer switches: Require physical interaction to transfer power from utility to generator. When power fails, you start your portable generator, connect it to the inlet box, then manually flip switches at the transfer panel to select powered circuits. Process takes several minutes and requires you to be home and available.
Advantages: Lower upfront cost, compatible with portable generators, provides circuit selection control, generator serves multiple purposes.
Limitations: Manual operation required, must be home during outages, not convenient for extended absences, weather-dependent startup.
Automatic transfer switches: Monitor utility power continuously 24/7. Upon detecting outage, the system automatically signals the standby generator to start and transfers house power within 10-20 seconds, completely hands-free. When utility power returns, the switch automatically transfers back and shuts down the generator.
Advantages: Fully automatic operation, functions whether home or away, no manual intervention needed, immediate power restoration, seamless operation.
Limitations: Higher initial investment, requires permanently installed standby generator.
Most homeowners investing in standby generators choose automatic transfer switches; after all, backup power that requires you to be home defeats the purpose. However, manual systems remain viable for budget-conscious homeowners comfortable with hands-on operation.
Let's discuss your specific situation. Mon to Fri, 8 AM to 5 PM.
Ready to Secure Your Home's Power?
On-site assessment and upfront, itemized pricing from a licensed electrician. No hidden fees, no pressure.
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What happens next
You tell us about your project and city
Our Wauwatosa-based team reaches out during office hours
You get your quote
414-404-6900
- info@lehmannelectrical.com
- 12012 W Fairview Ave, Wauwatosa, WI 53226
- Mon to Fri, 8:00 AM to 5:00 PM · Sat & Sun: Closed
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Service was prompt and efficient, estimator explained the job and options well.
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