
When your operations absolutely can’t afford disrupted power, a diesel generator delivers the muscle and reliability to power through outages of any scope. Diesel offers proven durability along with steady, fuel efficient performance – even in extreme conditions. For decades, Generac has engineered rugged diesel generators for commercial and industrial applications.
In this comprehensive guide, we’ll review Generac’s top diesel generator models, the unique benefits diesel provides, key factors in choosing the right size unit, proper operation and maintenance, FAQs, and more. By understanding Generac’s diesel generator capabilities and how to properly size and care for them, you can ensure power stays on no matter what emergencies or grid interruptions threaten your business or property.
Top 4 Generac Diesel Generator Models

Generac produces a full range of diesel generators from compact portable units up to massive industrial systems producing thousands of kilowatts. Here are 4 of their most popular models for a range of applications:
Generac SD050
This compact yet powerful model offers 5.4 kW of prime power in a highly portable footprint weighing just 133 lbs. It’s ideal for job sites, emergency response, rental fleets, and events.
Generac SG030
With three-phase 27 kW output, the SG030 works for agriculture, ranches, shops, and small commercial sites. It runs up to 18 hours on a single tank.
Generac SG100
This 94 kW workhorse can power a range of commercial facilities, hospitals, apartments, retail stores, and municipal buildings. It accepts multiple fuels.
Generac SG150
Need serious power? The SG150 provides 126 kW of prime power, enough for large facilities, construction sites, data centers, and infrastructure demands. It can integrate with existing systems as emergency backup.
All Generac diesel generators share important strengths like steel enclosures, industrial grade engines, safety features, advanced digital controls, and monitoring connectivity. Proper sizing is critical – overtaxing generators damages equipment over time.
Next let’s discuss the many benefits provided by a Generac diesel generator.
Key Benefits of Generac Diesel Generators

Proven Durability – Generac diesel generators withstand even extreme weather, high runtime demands, vibration, and repeated loading/unloading over decades of service life when properly maintained.
Fuel Efficient – Diesel fuel provides more energy density than gasoline or natural gas, allowing generators to extract more runtime from less fuel volume.
Powerful Performance – Generac utilizes heavy-duty diesel engines engineered specifically for generator use, not repurposed automotive or machine diesel engines. This results in better performance and longevity under generator demands.
Cold Weather Ability – Diesels operate in cold climates where gasoline engines struggle. Add glow plugs and fuel additives for reliable operation down to -40°F.
Large Fuel Tanks – With runtime directly tied to tank capacity, diesel generators use large fuel tanks that can operate uninterrupted for 10 hours or more when required. This prevents outages.
Wide Fuel Availability – Diesel is readily available worldwide, even if gasoline shortages occur. Hospitals, communications towers, and other critical operations often depend on generator diesel stores.
Advanced Controls – Generac diesel generators have commercial-grade controllers with advanced diagnostics, metering, alarms, multilingual displays, and connectivity to monitoring systems. Some integrate to automated building systems.
Dealer Support – Generac’s network of trained dealers provides turnkey emergency power solutions from design consultation through installation, fuel systems, and lasting service and support.
Diesel generators offer proven performance when outages threaten business operations. Next let’s explore key factors to weigh when selecting your Generac diesel generator.
Key Buying Considerations for Generac Diesel Generators

Electrical Load Analysis – The most critical step is to calculate your maximum electrical load during an outage so your generator can safely handle it. A licensed electrician can conduct a thorough load analysis based on your facilities’ systems and equipment.
Runtime Requirements – Estimate your needed runtime range based on previous outages and demand profiles. More runtime requires greater fuel storage capacity. Prioritize essential loads if operating in a curtailed capacity.
Noise Regulations – Local ordinances often dictate allowable noise levels for generators based on nearby buildings. Larger generators may require sound attenuation enclosures to reduce noise. Also factor in occupational hearing safety.
Mobility Needs – If Generator must be moved between locations consider a trailer-mounted unit with proper weight handling and safety equipment. Or choose a portable unit that can be lifted or wheeled.
Available Fuel Supply – Ensure access to an adequate diesel supply based on projected runtime needs, possibly including onsite bulk storage tanks. Maintain proper filtration and fuel maintenance.
Weather Conditions – In freezing climates, include cold start aids and block heaters to improve starting plus shelter the unit from snow and ice. In hot ambient temperatures, de-rate the generator capacity by 3% per 10°F over 77°F.
Phases and Voltage – Choose single or three-phase power generation matched to your electrical equipment. Ensure voltage, amps, plug compatibility, and load balancing for three-phase loads.
Factor in all these criteria plus long term costs over the generator’s service life when picking the right Generac diesel generator for your needs. This investment helps prevent very costly power disruptions.
Operation and Maintenance Tips

Proper operation and diligent maintenance are crucial to maximizing the working life of your Generac diesel generator:
- Closely follow Generac’s maintenance schedule in the manual for oil/filter changes, spark plug replacement, etc. Check and change fluids regularly.
- Only use clean, high-quality diesel with the specified cetane rating and ultra low sulfur content to prevent deposits and wear.
- Install good filtration systems to remove particulates and water from fuel.
- Shelter the unit from rain and snow. Ensure adequate airflow around the generator with at least 5 feet clearance.
- Never operate a diesel indoors or in partly enclosed areas due to dangerous exhaust.
- Periodically exercise the generator for an hour under at least 30% rated load. Don’t allow extended idle time.
- Keep spare maintenance parts like filters, drive belts, starter batteries, and glow plugs on hand for quick repairs.
Proper diesel generator maintenance prevents failures and significantly extends the generator’s service life. Now let’s look at some common questions about Generac diesel generators.
Frequently Asked Questions About Generac Diesel Generators
Q: What are the main benefits of a diesel vs gasoline generator?
A: Diesel generators offer better fuel efficiency, more stable fuel, greater power density resulting in smaller size/weight, increased cold weather ability, higher runtime capacity, and longer service life spanning decades.
Q: How frequently is maintenance required?
A: Expect to perform maintenance like oil and filter changes every 100-300 hours of operation. Inspect hoses, wiring, belts, clutch at least every 500 hours or 6-12 months. Maintain batteries. Keep the unit clean.
Q: How much power do diesels supply and for how long?
A: Diesel generators above 25 kW can provide prime power continuously when refueled. Small portable units may operate 10-25 hours. Larger units have virtually unlimited runtime potential using sufficient fuel storage.
Q: Can you safely run a diesel generator indoors?
A: No, diesel generators produce hazardous exhaust and must be positioned outdoors only. They require extensive ventilation clearance. Diesel vapor buildup poses explosion risk indoors.
Q: How long can a Generac diesel generator be expected to last?
A: With proper maintenance and operating conditions, Generac diesel generators can provide reliable service for tens of thousands of hours over decades of useful life across a wide range of loads and environments.
Rugged, Efficient Power – When You Need It
For unmatched reliability in the most demanding conditions, Generac’s diesel generators deliver industrial strength performance. Sophisticated controls and connectivity integrate seamlessly with your operations. Professional sizing, installation, and ongoing maintenance ensure your generator provides power through any grid disruption or emergency.
With diesel’s proven fuel efficiency, availability, and storage capacity, your generator can run continuously to protect your business assets and continuity. Avoid costly downtime by powering through any outage or disaster with Generac diesel generators. Contact a Generac dealer today gain power independence and control over your operations.