Common Generator Questions Asked | MAS Pro

For a whole-home standby unit, most homeowners in our area land somewhere around $8,000 to $16,000 all in. That covers the generator, the transfer switch, and professional installation. The range is wide because it hinges on the size of the unit, how far it sits from your electrical panel and gas meter, and whether your electrical or fuel lines need upgrades.

Portable setups paired with an interlock kit or a manual transfer switch cost far less to get running. We give you a firm number after a quick site visit rather than a guess over the phone.

A fully installed 22kW standby generator typically runs about $10,000 to $17,000 in our region. Roughly $6,000 to $7,500 of that is the unit plus a 200-amp automatic transfer switch, and the rest goes to electrical labor, the gas or propane hookup, a concrete pad, and permits. Older homes sometimes need a panel upgrade first, which adds to the total.

It comes down to fuel type and how hard the unit is working. A whole-home standby on natural gas often costs about $25 to $60 a day, while the same unit on propane runs closer to $120 to $200 or more. A portable gas generator usually lands around $40 to $70 a day. Running any generator at 70 to 80 percent of its rated load is the sweet spot for fuel efficiency and engine life.

If storm-season outages hit your neighborhood regularly, or if you rely on medical equipment, work from home, or want to avoid frozen pipes and a flooded basement, a standby generator earns its keep quickly. It starts automatically, can run for days on natural gas, and often adds to resale value.

The trade-off is the upfront investment and a modest yearly maintenance cost. If your outages are rare and short, a good portable may be all you need, and we will tell you so.

Here is the quick version. Sizing depends on what you want running during an outage, not just your square footage. The table below is a reliable starting point, and we confirm it with a load calculation before we ever quote a unit.

A 10kW unit produces about 41 amps at 240 volts, which comfortably covers the essentials: refrigerator, freezer, furnace blower, lights, a well or sump pump, internet, and a window AC. It will not run everything at once, though. Big 240-volt loads like central air conditioning, an electric range, or an electric water heater need to be managed or shed. Smart load-management modules handle that automatically so the generator does not overload.

A 20kW comfortably backs up most homes between 1,500 and 2,500 square feet, including one 3- to 5-ton central AC unit plus the usual household appliances. Try to start several heavy 240-volt loads at the exact same moment and you can exceed it, which is where intelligent load management helps. Homes over about 3,500 square feet or with dual HVAC systems usually step up to 24 to 26 kW.

Plan on 18kW to 24kW for true whole-home coverage. A 22kW is the workhorse for most 3,000 square foot homes and handles multiple high-draw appliances plus a 3-ton AC. All-electric homes, multiple HVAC zones, or EV charging push you toward 24 to 28 kW. A load calculation is the only way to size it correctly rather than guessing from square footage alone.

For hands-off whole-home backup that includes central AC, a 20 to 26 kW standby is the norm, because AC compressors demand a large surge of power to start. If you install a soft-start kit on the AC, you can cut that surge significantly and sometimes run the AC and essentials on a large portable or smaller unit in the 8 to 11 kW range. You give up the automatic convenience of a standby, but it can work for a tighter budget.

Not the entire house at once, but a 5000W generator will keep the important things alive during an outage: refrigerator and freezer, lights, WiFi, a few fans, and a small window AC. Skip the central AC, electric range, electric dryer, and electric water heater. Add up the running watts of what you want on, add the biggest single startup surge, keep the total safely under 5,000 watts, and stagger your startups.

Yes. A typical fridge draws roughly 300 to 700 running watts but can surge to 1,000 to 2,000 watts when the compressor starts, so use at least a 2,000-watt generator and a heavy-duty, outdoor-rated extension cord. For a modern fridge with an electronic control board, an inverter generator is the safest bet because it produces clean, stable power. Keep the generator at least 20 feet from the house.

Never plug a generator into a wall outlet using a double-male cord, sometimes called a suicide cord. That backfeeds electricity into the grid, can electrocute utility workers restoring power, and risks a house fire. The safe, code-compliant methods are a transfer switch or a generator interlock kit, both of which isolate your home from the utility line.

Because this ties into your main service panel, it needs to be done by a licensed electrician and permitted through Washington State L&I to meet the National Electrical Code and local rules. That is exactly the work our team does every week.

You use a generator interlock kit paired with an exterior inlet box. The interlock is a metal plate on your main panel that makes it physically impossible to have the main breaker and the generator breaker on at the same time, which is what prevents dangerous backfeed. A licensed electrician installs the inlet box, runs the wiring to a new double-pole breaker, and fits an interlock matched to your specific panel brand. It is the more affordable safe option compared with a full automatic transfer switch.

First, never backfeed your panel without a proper transfer switch. On a standard open-frame portable, avoid running sensitive electronics like computers and modern TVs directly on the dirty power it produces. Use an inverter generator or a quality surge protector or UPS instead. Be careful with high-surge 240-volt loads such as central AC and electric ranges, which can overload a portable, and keep medical equipment on clean, rated power.

Portable generators go at least 20 feet from the home with the exhaust pointed away from doors and windows. This one is non-negotiable, because carbon monoxide is deadly and invisible. The CPSC and CDC both stress the 20-foot rule.

Permanently installed standby units burn cleaner fuel and sit much closer, usually about 18 inches to 5 feet off the wall, but they still need at least 5 feet of clearance from any window, door, or fresh-air intake. Exact clearances vary by manufacturer and local code, which we confirm on every install.

A portable generator runs about 6 to 18 hours on a tank, then needs to cool down and refuel. A standby unit on a natural gas line can effectively run for days or weeks as long as the gas keeps flowing. On a 500-gallon propane tank, figure roughly 5 to 10 days depending on load. Whatever the fuel, plan on an oil and filter change every 100 to 200 run hours to avoid engine damage and warranty problems.

A standby generator, absolutely. That is what it is built for. A portable can run overnight for emergency power only if it is outdoors, at least 20 feet from the house, with working carbon monoxide detectors inside and the unit secured against theft. Many homeowners shut portables off overnight anyway to save fuel, since a closed refrigerator and freezer will hold temperature for hours without power.

Lifespan is measured in run hours rather than calendar years. A standby unit typically lasts 20 to 30 years, often 10,000 to 30,000 hours, with regular service. Portables run more like 10 to 15 years because of movement and outdoor wear. The biggest factors are keeping the unit at a healthy 70 to 80 percent load, sizing it correctly so it is not overloaded or constantly underloaded, and staying on top of routine maintenance.

For portable and home backup use, inverter generators are the most efficient. Instead of running at a constant speed, they throttle the engine up and down to match demand, which saves fuel, runs quieter, and produces clean power for sensitive electronics. For heavy continuous or industrial loads, diesel units win on fuel efficiency because of their higher compression and denser fuel.

Generac and Kohler get the most name recognition, and Generac holds the largest market share and the widest dealer network. In practice, the brand matters less than the quality of the install and the service behind it. A generator is only as dependable as the electrician who sized it and the company that maintains it.

We install and service several major brands and help you pick the right unit for your home and budget, then stand behind the work here in Clark County.

The main drawbacks are cost, since the unit plus a proper install runs high, and strict warranty rules that can require OEM parts and certified service. Add annual maintenance averaging a few hundred dollars, the space a pad-mounted unit needs away from windows and vents, and some noise during the weekly self-test. They are a solid, well-supported choice. Just go in knowing the ongoing costs, and remember that a correct professional install is what keeps the warranty valid.

Across any brand, the honest downsides are the higher upfront cost, regular servicing to keep it reliable, the physical space needed for the pad and clearances, and a bit of running noise. For most homeowners in outage-prone areas, the automatic, hands-off backup during a multi-day outage outweighs all of that. We will tell you straight if your situation points to a portable instead.