How much can a 7500 watt generator run? A 7500W generator is one of the most popular generator size on the market, and for good reason — it can power a lot of electrical devices. A 7500W generator can get you through a power outage with ease, or a natural disaster.
This is an interesting question, often asked when considering a generator. Can a 7500W generator power my entire house? Is 7.5Kw enough for the chicken coop during power cuts? Will it power the entire RV? These are important questions that need clear answers and guidelines that will assist you in determining for yourself whether a 7500W generator is going to deliver the power that you need. To do this, you need to understand what a generator can do and what its limitations are. We review three 7500 Watt generators but first, I’ll explain how much 7500 Watts can run.
Generator : What are Running & Starting Watts
Before we delve too deep into the meaning of running and starting watts, let’s stop for a moment to consider what a Watt is. A watt is a unit of power named after James Watt. In the International System of Units, it’s defined as a unit of 1 joule per second. A Watt is not current or volts, it’s equal to Volts times Amps. So many loosely refer to “running Watts” as running current that I felt an urge to make this point clear. A generator producing 7500 Watts, at 240 Volts, produces a current of 31.25 Amps. However, it will most likely be limited to less than that. A generator’s load can be expressed as Watts or current at 120 or 240 Volts.
What are Running watts?
Running watts is the power the generator delivers when you connect it to a passive load like a resistive heater, house lighting, or underfloor heating. As long as you do not interfere, these loads do not change while in use. This steady power demand is predictable and can be easily calculated. It’s referred to as the running Watts of the generator. Anything that you switch on while a generator is supplying power will add to the generator’s load. The running Watts of the generator is limited by the current it’s allowed to deliver. Even though some manufacturers rate their product as being a 7500 Watt generator, it may be limited to 29 Amps. At that limit it delivers 29A X 240V = 6,960 Watts.
What are Starting watts?
The starting watts is also referred to as a switch-on surge. More precisely, it’s an inrush current, or input surge current. It’s an instantaneous high input current drawn by some electrical equipment when turned on. It’s mostly caused by inductive loads like a power supply, transformer, welder or electric motor. But even heaters or incandescent lamps demand a startup current.
The capacitors in power supplies are discharged when off and offer an initial low impedance that draws high currents when power is switched on. Normally, it only lasts for about 10 milliseconds but the current drawn can be as high as 20 times the steady state or running current. A good design will limit the inrush current to protect the equipment. It lowers the maximum current, and as a result, extends the time that the current is high. It can then last up to a second or two. It’s sometimes visible as a dip in the power supply, such as a light dimming. A generator will sound different or lose speed for a second or two.
Whisper-Quiet 7000W Inverter Generator | Honda Eu7000is (Review)
Another source of startup current is caused by motors and inductors or transformers in the equipment. A 15,000-BTU, 115VAC air conditioner can require 16 amps running current (1,840 Watt) when both the compressor and blower motors are running. The AC motors in the air conditioner can create a high inrush current at startup of up to 30 Amps or 3,450 Watt.
It will surprise many that incandescent heat lamps create a large inrush current when first powered on. A single 5″ 250 watts, 120 VAC, R40 reflective heat lamp used in chicken coops has a hot resistance of 58 Ohms. Its steady state current is just over 2 Amps (240 Watt). However, when cold, the filament resistance is only about 3.8 Ohm. It will produce an inrush current of around 31 Amps (3,720 Watts) for one-tenth of a second when power is turned on. Ten lamps use 2,400 Watt, but the generator must cope with a startup current of 37,200 Watts if all are turned on at the same time. You’ll need more than one switch or a startup current limiter to control the lamps.
How much can a 7500 watt generator run?
The running Watts is the maximum power that the generator can deliver on a continuous basis. If this load is not exceeded, it will not be overloaded and the protection circuits will not activate. The starting Watts is the maximum power allowed during startup demand. It’s allowed for a second or two only, and it’s normally monitored by the Automatic Voltage Regulator (AVR). A generator with 9,500 startup Watts can deliver a total current of 39.6 Amps for a second or two. If the current remains this high for longer, it cuts the power.
Can a 7500W generator power your entire house?
No, it cannot power all the electric equipment in an average American home, if they’re all used at the same time. The typical American house use 100 amps or more. Electrically heated homes, homes with central air-conditioning or clothes dryers typically use 150 to 200 amps. At 240 Volts and 150 Amps, it means you need a generator that can deliver 36,000 Watts. So you have to compromise in choosing which appliances should be used and how they should be grouped together.
Following the reviews, I explain how a 7500 Watt generator can be used to power a home.
7500 watt Generator Reviews | What can they run?
We review 3 excellent 7500 Watt portable generators. All are conventional open frame, gas-powered generators. We did not include any inverter generators, even though conventional generators are not the best for the sensitive electronic devices in a modern home. To circumvent the generator’s “dirty” power problem, I introduce low-cost solutions in the reviews. We’ve chosen the following 7500 Watt generators for this review.
- Westinghouse WGen7500 : 7500 Running Watts, 9500 Peak Watts.
- Champion Power Equipment 100538 : 7500 Running Watts, 9375 Peak Watts.
- Cat RP7500E : 7500 Running Watts, 9375 Peak Watts.
Westinghouse WGen7500 — Portable Generator
with Remote Electric Start, 7500 Running Watts, 9500 Peak Watts.
- 7,500 running watts, 9,500 peak watts
- Push-Button Start and Remote Start (Key Fob Included)
- Up to 16 Hour Run Time (6.6 gal)
- 420cc Westinghouse OHV Engine with Cast Iron Sleeve
- Transfer switch ready
- VFT Data Center (Volts, Frequency, and Lifetime Hours)
- 3-Year Warranty and Lifetime Technical Support
- EPA, CSA, CARB Compliant
- 6.6 Gal. fuel tank with fuel gauge; up to 16 hour run time
- Weight : 192 lbs
- 73 dBA operating volume
- Outlets :
- 2x GFCI (Ground Fault Circuit Interrupter) 5-20R 120V Household Duplex Receptacle
- 1x L14-30R 120/240-Volt twist-lock receptacle
- Plug-and-play: Comes with a 12-Volt battery charger, oil, an oil funnel, a tool kit and a user’s
- Automatic low oil shutdown and overload protection
The 9,500 starting Watts of the Westinghouse 7500 Watt generator is 125 Watt more than the 9375 Peak of the other two 7500 Watt generators. Like the other two generators, it’s a conventional open frame generator. The Westinghouse generator has the convenience of electric starting, and includes a remote key fob. You don’t have to be at the generator to start it, a handy feature in bad weather. Instead of running outside, braving a storm to start the machine, you can do it from the safety of your home.
VIDEO | Learn More on the Westinghouse WGen7500
Having the generator prepared for a storm also means that it’s protected from rain and snow. Homeowners using their generator during a storm, must keep in mind that the generator needs to be outside, a safe distance from windows and doors. A wonderful solution is the GenTent storm cover that allows you to safely run your portable generator outside in wet weather.
You also need to drive a spike into the ground, providing a frame ground for the generator. The Westinghouse 7500 Watt generator has neutral bonded to the frame, but can be removed. For your own safety, I recommend consulting an electrician when doing this.
It’s comforting to know that with a full 6.6 Gallon tank, the Westinghouse generator will run at 50% load for 11 hours. You will not be running it at a constant 50%, so this running time will vary. But at night, it should easily power all the security, refrigeration, and some personal heating needs until morning. At 100% rated power, a full tank will last 5.5 hours. It’s not possible to use a generator at 100% power due to fluctuations in demand. However, it’s a worst-case figure. The Westinghouse is surprisingly fuel efficient, delivering 6.25 kilowatt-hours per gallon. This is better than most generators, much better than the other two 7500 watt generators in this review. This monster generator will save you a lot of fuel.
Its noise level of 73dBA at 23 feet is 1dB lower than the rest – not too bad for a big open frame generator. Unfortunately, bigger generators are noisy, and it can be annoying after some time. If you feel the urge to do something about this, the best solution is to rest four boards against it at a 45° angle. The inside surfaces, this deflects some of the noise down to the ground, still leaving enough airflow to cool the generator.
The Westinghouse WGen7500 Watt generator is heavy, weighing 192 pounds. Fortunately, it has two 10″ wheels and folding handles to move it around. This is a big generator, requiring extra storage space. Remember to drain all the fuel from the unit and run the carburetor dry when putting it away for the season. However, the manual may suggest some alternate storage solutions, so please read the manual. The point is that fuel deteriorates during storage.
The power output of this conventional generator has too much line noise for sensitive systems, like your computer and entertainment systems in the home. Its Total Harmonic Distortion (THD) is < 23%. For those sensitive systems, you need less than 5% THD. We posted an interesting article explaining all the THD and clean power issues, it’s worth reading if you wish to understand more: Inverter vs Generator? What’s the Difference? Everything You Need to Know.
It’s possible to use a power or line conditioner to “clean up” the power delivered by the generator. Line conditioners are also known as power conditioners, they regulate and filter the generator output to produce clean power that’s suitable for sensitive electronics. A Tripp Lite Power Conditioner is one such device that offers all the regulation and protection you need. You can use small units to power the sensitive equipment only or large ones to power circuits in the home.
This powerful 7500 Watt generator has all its convenient outlets grouped together on the user interface panel and includes a main breaker, which limits the output to 31 Amps. At 240V, 31A is equivalent to 7440W, which is close enough to the rated maximum of 7500W. It’s fitted with one 120/240 Volt AC, 30 Amp Twist-Lock Receptacle (NEMA L14-30R). The only additional receptacles are two Duplex 120V 20A GFCI (5-20R) outlets. All the outlets are protected by rubber covers to ensure that they stay clean and will always make good contact.
The Datacenter on the user interface displays some interesting information that you select with a button. You’ll see either Volts, frequency, or lifetime hours, depending on the selection. The Westinghouse has a 12V DC output for charging batteries. The generator charges the onboard battery when it’s running. When storing the generator, the battery should be charged periodically. To facilitate one button, and remote fob starting, the generator has an electric choke. So even though a recoil starter is included, you need a charged battery to start it, if the choke is required. The fuel shut-off controls are not on the control panel, but under the tank, close to the carburetor.
A low oil shutdown system protects the engine, it kills the engine when the oil level is too low. Remember this could be a reason for the engine failing to start. It’s best to check the oil level every time you use the generator.
You can remove the regulatory spark arrester in the muffler to clean or replace it. The generator has all the necessary emission certifications for the USA and Canada. The 6.6-gallon fuel tank has a built-in fuel gauge. You can quickly dash out and determine how much longer your fuel is going to last.
The Westinghouse is a good choice for any of your portable power needs. It is powerful enough to power most of the tools on a worksite simultaneously, and it’s great for powering the home. For home use, I recommend that you install a 30A transfer switch, either from Westinghouse or another trusted manufacturer. This makes the installation safe and legal. In conjunction with a power conditioner, it delivers clean power where needed.
I can recommend the Westinghouse, it’s from a solid American company with a good reputation, and will provide for all your needs. It’s EPA, CSA, and CARB Compliant, is covered by a 3-Year Warranty, and Lifetime Technical Support.
Champion Power Equipment 100538
7500 Running Watts, 9375 Peak Watts.
- All the backup power you need for power outages and emergencies.
- 420cc Champion single-cylinder OHV engine
- Can handle multiple power tools and large equipment you need to get the job done.
- Electric start with included battery
- Cold Start Technology ensures a quick start in cold weather.
- Intelligauge monitors voltage, frequency and operating hours
- Foldaway U-shaped handle and never flat tires make it easy to move around
- 9375 starting watts and 7500 running watts
- Can power a wide range of devices in an outage – lights, refrigerator, modem/router, security system, window AC, furnace blower, TV, computer, phone charger and more. Not only that, but the Volt Guard built-in surge protector prevents overloads and keeps your equipment safe from spikes in voltage.
- All the outlets have covers for protection
- 4x 120V 20A GFCI protected household outlets (5-20R),
- 1x 120/240V 30A locking outlet (L14-30R)
- 1x 120/240V 50A outlet (14-50R).
- 5.7-gallon tank of gasoline
- up to 8 hours of power at 50% load. From 23 feet
- Noise level is 74 dBA, a little louder than a vacuum cleaner.
- Designed with a low oil shut-off sensor
- 1.2-quart oil capacity (recommended 10W-30).
- EPA certified and CARB compliant.
- Champion Support and our nationwide network of service centers will back your purchase up with a 3-year limited warranty and FREE lifetime technical support.
✓ View or download the MANUAL for the Champion Power Equipment 100538.
The Champion 100538 7500-Watt generator runs on gas only, and it’s powered by a 420cc Champion engine. Its fuel efficiency is average, 5.26 kilowatt-hours per gallon. It’s slightly better than average of of 20 generators that we evaluated, far from being the worst. So far, the Honda EU7000iS is the best at 7.01 kilowatt-hours per gallon.
This 7500 Watt generator weighs 192.5 pounds and it’s mounted in a sturdy frame with a comfortable fold-down handle. It is equipped with two 10” wheels that make it moveable. Mounted to the one side of the frame, is the control panel with a clean, neat layout. It has a 120/240 Volt NEMA outlet, 50 Amp (14-50R) and a 120/240 Volt AC, 30 Amp Twist-Lock Receptacle (NEMA L14-30R). Both outlets are protected by 30 Amp push to reset breakers. Two duplex GFCI 120 Volt 20A (5-20R) home-style connectors with 20 Amp push to reset breakers are also fitted. Dirt and moisture can erode contacts, so the neat flip-up rubber covers are a good addition.
Control Panel | Champion Power Equipment 100538
There is no DC outlet for charging 12V batteries or a nut that can undo the neutral-to-frame connection. There is only a note on the panel that neutral is bonded to the frame. The running hours, output voltage and frequency are displayed on the three-mode digital meter as you select them.
A 12-Volt DC battery powers the three-way switch for run, stop, start, and an electric starter. The fuel flow valve and the choke are manual, so this model cannot be started remotely. This engine is equipped with a low oil shut-down detector, preventing engine damage.
A 12 Volt 15AH battery is supplied with the generator and is recharged while the engine is running. If the generator is seldom used, it’s better to fully charge the battery at least once a month. This will keep the battery in good condition and ensure that the generator starts when you need it. Should the battery run flat, a recoil starter is provided.
The Champion generator is not fitted with a fuel level indicator. Unfortunately, you have no way of knowing the fuel level. You may be tempted to open the cap while the generator is running to peek inside, but this dangerous. The running motor causes vibrations that can cause fuel to spill onto the hot engine parts, which may cause a fire or explosion.
A run-time of 8 hours on a full tank of 6.1 gallons is given for a 50% load. I calculated the consumption as 5.26 kilowatt-hours per gallon. It’s an average consumption, comparable to the Cat RP7500E, but less than the Westinghouse.
The noise level for this generator is given as 74dBA from 23 feet. It’s an average reading for an open frame generator, louder than a vacuum cleaner and better than a lawnmower up close. That reading is taken at 23 feet, up closer to the generator it’s very loud. Homeowners using it during outages complained that the machine is too loud.
This 7500 Watt generator is EPA and CARB compliant and the exhaust is fitted with a spark arrestor. It’s therefore approved for use in national parks. An Automatic Voltage Regulation (AVR) automatically maintains the generator output voltage to the required level. This is a great advantage, the voltage will not fluctuate under varying loads. You will simply hear the engine working harder.
You can buy this generator with confidence, due to Champion support and a nationwide network of service centers. It comes with a 3-year limited warranty and free lifetime technical support.
7500 Running Watts, 9375 Peak Watts.
- EPA Compliant
- The RP7500E offers 9375 Watts of starting power and 7500 running Watts
- 3600 engine RPM
- can run for 11 hours at 50% capacity.
- Electric or recoil starting method
- OHV engine with a displacement of 420 cc
- Automatic Voltage Regulation (AVR) and an AC voltage of 120/240V, as well as an AC frequency of 60Hz.7.9 gallon fuel tank
- Holds a lithium ion battery that charges while the generator is in use so that it’s ready when the fuel runs low
- Fuel gauge on the tank show fuel levels, and when the fuel is low, the generator will shut down.
- Double-folding handle makes the generator easy to carry and store
- wheels never go flat and are always ready to roll.
- CAT RP7500E has a 36-month limited warranty for products registered within 30 days of purchase.
Documents for the CAT RP7500E :
- View or download the ✓ MANUAL
- View or download the ✓ SPEC SHEET
- View or download the ✓ ELECTRICAL SCHEMATIC
The CAT RP7500E is comparable to the Champion in power output. It delivers 9,375 starting, and 7,500 running Watts.
It runs for 11-hours at a load of 3752 Watts on one tank of gas. I calculated the runtime at 100% load to be about 5.43 hours. Fuel efficiency for the Cat RP7500E is 5.22 Kilowatt hours per gallon. It is not as fuel-efficient as the Westinghouse, but not by much. Its fuel tank is the biggest of the three at 7.9 gallons. Therefore it has a longer runtime. It’s an advantage during an outage or while weathering a storm.
Cat (also known as Caterpillar) does not specify the noise levels and THD for their generators, but I think the line noise will be greater 5% THD. When using it to power the home or RV, it’s advisable to use a line conditioner for sensitive equipment. The wattage or Amps of your line conditioner must accommodate the total load of the equipment that you connect to it.
At 74dBA, the Cat 7500 Watt generator is noisy, as loud as a freeway at 50 feet. Using a loud generator that’s running for extended times can be problematic when near the RV or campsite, or when used at home. I searched the internet and found some ingenious home-built enclosures that dampen the sound down to a comfortable 62dBA. Additionally, it protects the generator, and acts as storage. It’s worth investigating.
Surprisingly, the Cat 7500 Watt generator is more than 5 inches longer than the Westinghouse. This generator weighs an uncomfortable 205 pounds. Though the design makes it easy to move around because the weight is balanced over the big wheels.
The interface panel is mounted at the rear of the generator, which enabled Cat to include the choke and fuel valve on the panel. The Cat has more outlets than any of the other 7500 Watt generators in this review. One 120/240 Volt, 30 Amp NEMA L14-30R twist-lock receptacle limited by a 28 Amp trip switch. One 120 Volt 3-prong twist lock (L5-30) also with a 28Amp cut-out. Two duplex GFCI 5-20R 120 Volt, 20 Amp receptacles.
All the outputs are protected by rubber weatherproof covers. The Cat uses a 4 in 1 digital display similar to the Westinghouse, displaying voltage, frequency, running hours, and total hours.
This 7500 Watt generator does not have a DC output to charge batteries. The electric start control does not have a remote start feature. A manual choke and fuel control valve are located near the start control. You turn a stop/on/start-switch to start the engine. A unique addition to the user interface panel is an LED light that illuminates the panel controls. A thoughtful addition that will be much appreciated when using your generator at night.
A fuel gauge is fitted to the fuel tank, to safely determine the fuel level. It’s an important safety feature because the alternative is to open the cap and look inside, possibly spilling gas. This 7500 Watt generator is fitted with a low oil shutdown system that kills the engine when the oil level is too low. The generator’s emission certification is compliant in all states.
Selecting a favorite from the three 7500 generators will depend on the total startup load, price and possibly the provided power outlets. Personally, I tend to favor the Westinghouse because of its remote start facility.
Connecting sensitive electronic devices to a conventional generator
Higher temperatures in sensitive electronics are caused by Unwanted Harmonic distortion. Frequency harmonics of higher frequencies increases core loss in motors, resulting in the rotor core overheating. The harmonic interference of conventional generators can significantly shorten the life of electronic equipment due to the higher temperatures.
The one solution I’m proposing is to use a small Tripp Lite Power Conditioner that offers all the regulation and protection you need. You use it to power the sensitive equipment only. A typical line or power conditioner will also have an Automatic Voltage Regulator (AVR). Like the one fitted to the generator. It also has AC Surge Protection and power outlets. It protects sensitive electronics from overheating when powered by a generator.
Additionally, it prevents surges and spikes from damaging circuitry and filters out disruptive line noise from the generator. It’s Ideal for routers, modems, printers, and entertainment equipment. It can be used in the RV, camping, tailgating, or wired to the home circuits.
Line conditioners smooth the sinusoidal A.C. wave by removing the harmonic distortion. They maintain a constant voltage over varying loads even if the generator fails to do so.
Examples — How Much Can A 7500 Watt Generator Run?
Common wattage for everyday electrical devices
When powering appliances in the home, you may find that you cannot use the most essential appliances with the air conditioner running. The air conditioner is one of the most power hungry units in the home. It may, at times, be necessary to stop the air conditioner while using some other appliances. Three 18 Watt lamps, 1 refrigerator, a 625 Watt microwave, a blender, and a toaster already consume a total of 2129 running and 2729 startup watts. Add to that, the air conditioner using 1500 Watts and the total demand is 3629 running and 6629 startup watts. At this point, you’re consuming 27.6 Amps at 240 Volts. So, you will have to limit the appliances that you run simultaneously to be sure you do not exceed the 30 Amp limit.
Examples of what it takes to run common electric devices
You always have to carefully consider which devices, like a sump pump or furnace fan blower, you add to the mix. The start-up current of these devices is quite high, and they also consume more when running. On the internet, you will find lots of wattage lists for appliances in the home, RV, and workshop.
Example 1 : How Much Can A 7500 Watt Generator Run? Typical home Devices :
- 5 Energy saver lamps of 18 Watt each
- 1 x Refrigerator/ Freezer, 200 Watt
- 1 x Sump Pump – 1/2 HP, 1050 Watt
- 1 x Microwave Oven – 625 Watts
- 1 x Coffee Maker, 1000 Watt
- 1 x Toaster, 850 Watt
- 1 x Hair Dryer – 1250 Watt
- 1 x Personal Computer w/ 17″ Monitor, 800 Watt (Tube type)
- 1 x WiFi router, 12 Watt
- 1 x Cell Phone Battery Charger, 25 Watt
With everything in use, the total running watts would be 5902 Watts. The startup load will be 8102 Watts when the Sump pump starts up. It’s a comfortable load for any of the 7500 Watt generators we looked at. If you add an AC – 10,000 BTU that consumes 1500 Watt the running watts jump to 7402 Watts. Unfortunately, the startup load becomes 10402 Watts.
Another problem is that the air conditioner switches on and off all the time. To live with the air conditioner on, you will have to stop using the toaster and microwave oven. More combinations are possible of course, but this is a common situation.
Any of our 7500 Watt generators can be used to power tools in the barn or on a worksite. Generally, workman’s hand tools use 120V receptacles. Therefore, the 120-volt load is important. This generator can handle 62.5A running amps at 120 Volts, this is exactly 7200 Watts. It can deliver 78.1A starting amps at 120V (9372 Watts). As an example of the typical load of hand tools I selected the following tools, using one each simultaneously:
Example 2 : How Much Can A 7500 Watt Generator Run? Common Power Tools :
- Reciprocating Saw – 960 Watts
- Electric Drill – 1/2″, 5.4 Amps – 600 Watts
- Circular Saw – 7-1/4″ – 1400 Watts
- Planer/Jointer – 6″ – 1800 Watts
- Table Saw or Radial Arm Saw – 10″ – 2000 Watts.
The total running wattage is 6760 Watts, and the starting load is 9060 Watts. It’s, therefore, a safe load for the generator. You can use more tools though. It’s unlikely that all your tools will be used at the same time, as in this example. This would be a busy work environment.
A 7500 Watt generator also successfully powers an RV. The list below uses 5956 running, and 8256 starting Watts:
Example 3 : How Much Can A 7500 Watt Generator Run? Typical RV :
- 1 – Trailer Air-Conditioner – 1000 Watts
- 1 – TV – 200 Watts
- 1 – Mobile Phone/Tablet – 100 Watts
- 3 – Energy saver lights – 18 Watt – 18 Watts
- 1 – Refrigerator/ Freezer – 200 Watts
- 1 – AM/FM Radio – 100 Watts
- 1 – CD/DVD Player – 100 Watts
- 1 – Box Fan – 20″ – 200 Watts
- 1 – Microwave Oven – 625 Watts
- 1 – Coffee Maker – 1000 Watts
- 1 – X-Box, Game Cube, or PlayStation – 40 Watts
- 1 – Hair Dryer – 1250 Watt – 1250 Watts
- 1 – Personal Computer w/ 17″ Monitor – 800 Watts
- 1 – Wi Fi router – 12 Watts
- 1 – Outdoor Light String – 250 Watts
- 1 – Cell Phone Battery Charger – 25 Watts