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Verified Reviews for Generator Install pros in Johnsonville, SC

*The Angi rating for Generator Install companies in Johnsonville, SC is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

*The HomeAdvisor rating for Generator Install companies in Johnsonville, SC is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Generator Install needs.

Last update on June 05, 2026

Find Generator install pros in Johnsonville

Avatar for Mister Sparky of Florence
Mister Sparky of Florence
5.0(
16
)
Fixed Generator - InstallPortable Generator - InstallFixed Generator - Repair+4 more

Serving Johnsonville, SC and surrounding areas

Approved

Super Service Award Winner

In business since 2004

Free estimates

Emergency services offered

"Daniel, their electrician has helped us before. He arrived promptly and after discussing with us our issues went directly to work addressing our problem. He successfully completed his work to our satisfaction, discussed the repairs , and was on his way to his next appointment in a very timely manner. We are extremely satisfied with his work in particular and Mr Sparky in general in addressing our needs. Reliability and competence seem to be their hallmark."
Install - Under Cabinet Lighting
Install - Outdoor Outlets
Install - Outlet Replacements
Install - Outlet
Install - Door Bell

+5

14 neighbors recently requested a quote
Recommended by31%of homeowners
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Avatar for Smith Electrical And Telecommunication Services LLC
Smith Electrical And Telecommunication Services LLC
5.0(
4
)
Fixed Generator - InstallFixed Generator - RepairGenerator - Repair - For Business+1 more

Serving Johnsonville, SC and surrounding areas

Approved

In business since 2025

Free estimates

Credit card accepted

"Got the job done quick, and for a good price!"
Smith Electrical
73 neighbors recently requested a quote
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Avatar for Swift Services Heating & Cooling, LLC
Swift Services Heating & Cooling, LLC
4.0(
64
)
Fixed Generator - InstallPortable Generator - RepairFixed Generator - Repair+1 more

Serving Johnsonville, SC and surrounding areas

Approved (Corporate)

In business since 1997

Free estimates

Emergency services offered

"Swift is an efficient and professional service company. They installed my new air conditioner quickly and with no problems. They were on time, and the installers were friendly and courteous. I would recommend them to everyone. I would not use anyone else for my AC service. They are the best!"
Response time10 hrs
47 neighbors recently requested a quote
Recommended by91%of homeowners
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Avatar for Rabon Brothers Services, LLC
Rabon Brothers Services, LLC
5.0(
3
)
Fixed Generator - InstallFixed Generator - RepairGenerator - Install - For Business+1 more

Serving Johnsonville, SC and surrounding areas

In business since 2023

Free estimates

"Very professional, showed up on time, performed the generator service and was a pleasure to work with. You wonâ t go wrong hiring the Rabon Brothers!"
Response time4 days
Recommended by100%of homeowners
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Avatar for B1 Electric, LLC
B1 Electric, LLC
4.1(
30
)
Fixed Generator - Install

Serving Johnsonville, SC and surrounding areas

In business since 2016

Free estimates

Small jobs welcome

"Perfectionists, meticulous, cordial, and punctual!!!! Everything installed was done well. One of the installers even corrected electrical mistakes caused by our builder. Intend to hire them again for additional projects and will recommend to other residents in this community."
200A Service Upgrade
200A underground Service with disconnect
Kitchen lighting Project
Outdoor lighting and outdoor 100A electric service
Exterior Ceiling Fan with Leaf Design

+4

Response time4 hrs
Recommended by96%of homeowners
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Showing 1-10 of 23
Generator Install questions, answered by experts

It might seem counterintuitive, but installing a generator transfer switch will save you money in the long run. While you’ll have to pay between $400 and $2,500 to have the transfer switch installed, you’ll recoup that amount later on when you don’t have to pay for expensive repairs to your appliances, devices, and electrical system that may have burned out, overloaded, or stopped working due to a sudden loss of power or an incorrect hook up of a generator to your home. 

To determine the right size generator for your house, you should calculate the total wattage of the appliances and devices you want to power during an outage. List all essential items, note their start-up wattages, and add them together.

Here are some typical wattage requirements for common appliances:

  • Refrigerator: 600 watts

  • Large dehumidifier: 700 watts

  • Large window air conditioner: 1,400 watts

  • Water heater: 3,000 to 4,500 watts

  • Electric furnace: 5,000 to 25,000 watts

A 7,500-watt generator might be sufficient for essentials like a refrigerator, freezer, well pump, and lighting circuits. However, for high-demand items like a water heater or furnace, a whole-home generator is a better choice. A portable generator may be enough if you only need to power a few critical items.

While home square footage can offer a rough estimate, it is not always a reliable indicator. For reference, here are some typical generator sizes based on square footage:

  • 1,000 sq ft: 6–9 kW

  • 1,500 sq ft: 7–10 kW

  • 2,000 sq ft: 10–14 kW

  • 2,500 sq ft: 12–16 kW

  • 3,000 sq ft: 16–20 kW+

For the most accurate sizing, consult a professional who can calculate your home's peak and average power consumption and recommend the optimal generator.

Yes. You can connect your home back-up battery to a generator with its designated charger. Be sure that the output of the generator matches the input requirements for the battery for best results.

Sizing a generator is a careful process that requires calculating the electrical load of your entire house. You have to take into account every device you want to use and their wattage requirements, plus the wattage needed to start them, and look for a generator that can safely run all that at around 80% capacity.

In more practical terms, a small home can run on a 10,000-watt generator (and if you only want to power a few key appliances, much less than that). A mid-sized home may need something between 15,000 and 22,000 watts. Larger homes require 25,000 watts or more. 

These advanced generators use a key fob or a smartphone app to remotely start, which is ideal for getting power back on immediately without venturing outside. This feature is more common on whole home generators, but you may be able to find it on large portable generators, too.

The Johnsonville, SC homeowners’ guide to generator installs

From average costs to expert advice, get all the answers you need to get your job done.

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