Everything You Need to Know Before Buying a Used Generator

Common Mistakes When Buying a Used Generator

Purchasing a used generator can save money, but avoiding common mistakes is crucial. Consider the generator’s condition, dealer reputation, and warranty before making a decision. Many buyers overlook key factors, leading to costly errors such as:

• Choosing an unreliable dealer
• Ignoring the hours reading
• Overlooking essential features
• No load and testing history
• Not inspecting the generator’s overall condition
• Overlooking the availability of spare parts
• Failing to consider fuel efficiency and long-term costs
• Choosing the wrong power capacity for their needs
• Not factoring in noise levels for residential or commercial
• A used machine’s history, and where it came from is important, and how it’s been maintained.

Choosing a Reliable Dealer

Where you buy your generator matters. A reputable dealer ensures the unit has been tested, serviced, and maintained before resale. Certified dealers often provide peace of mind, with load bank testing reports and service records, reducing the risk of unexpected failures. Private sellers may offer lower prices, but without proper checks, you could end up with an unreliable unit, and a shortage of machines available.

Ask the dealer about the generator’s history, previous applications, and any maintenance records. A good dealer should provide transparency regarding the unit’s performance and offer post-sale support. Online reviews and customer feedback can also help you determine if the dealer is trustworthy.

Checking Usage Hours and Age

A generator’s age and usage hours affect its performance and lifespan. Most generators have an hour meter that tracks running time. Compare this with the generator’s age to assess wear and tear. A high number of hours could indicate extensive use and potential maintenance issues. Conversely, an older generator with low hours may have outdated parts that are difficult to replace. Balance these factors to ensure reliability and long-term value.

Check for inconsistencies between the generator’s physical condition and the reported usage hours. Some sellers may reset hour meters, so a professional inspection can verify if the wear and tear match the reported usage.

Evaluating Key Features

Different generators offer varying features. Identify your power needs before purchasing. Some key considerations include:

• Fuel Type: Diesel, petrol, natural gas, or propane—each has pros and cons. We only deal with diesel.
• Power Output: Ensure the generator meets your required capacity.
• Automatic Transfer Switch (ATS): Provides seamless power transitions.
• Portability: Some models are easier to move and install than others.
• Paralleling Capabilities: Ability to link multiple generators for higher power output.
• Digital Control Panels: Offer user-friendly monitoring and diagnostics.

Research modern advancements in generator technology to ensure you get the most efficient and reliable model.

Importance of Load and regular runs.

Testing a used generator is essential to verify performance. A load test measures its ability to handle power demand. A no-load test helps detect basic operation and machine condition. Without these tests, you may invest in a generator that cannot handle your operational needs.

Professional load testing simulates real-world conditions, ensuring the generator operates as expected under varying demands. Ask your dealer if they can conduct a live demonstration or provide recent test results.

Reviewing Warranty and Guarantee Details

Some used generators come with warranties, but many buyers neglect to review the terms. Certified dealers typically offer limited warranties covering repairs or replacements. Read the fine print to understand what is included and confirm that you receive all necessary documentation.

A warranty is a sign that the dealer stands behind the product. If no warranty is offered, ensure that the generator has undergone thorough testing and comes with a service history that proves its reliability.

Inspecting the Generator’s Condition

Before purchasing, inspect the generator for visible signs of wear. Check for:

• Rust, dents, or cracks on the body
• Leaks around the engine, fuel tank, and connections
• Corrosion on wires or terminals
• Unusual sounds during operation
• Loose bolts or missing components
• Different engines can develop different common faults, its important to research what you plan to purchase.

If possible, have a professional assess the generator’s internal components, including the alternator, voltage regulator, and exhaust system, to ensure everything is in working order.

Fuel Efficiency and Running Costs

Fuel efficiency affects the long-term cost of ownership. Diesel generators are known for their durability and low fuel consumption, making them ideal for commercial and industrial use. Petrol and natural gas models may have lower upfront costs but higher running expenses. Choose a generator with a fuel system that aligns with your budget and operational needs.

Check the manufacturer’s fuel consumption rates at different loads. Over time, a more fuel-efficient generator could save thousands in operational costs. Additionally, consider fuel availability in your area, as some fuel types may be difficult to source.

Managing Noise Levels

Noise can be a concern, especially in residential areas. Some generators run quietly, while others produce significant noise. Consider:

• Inverter generators: Quieter than standard models
• Sound enclosures: Help reduce noise levels
• Location of installation: Placing the generator away from occupied areas minimises disruption
• Exhaust modifications: Specialised mufflers can reduce noise
• Regulatory compliance: Local noise regulations may limit the types of generators you can use

Testing the generator’s noise output before purchasing ensures compliance with local regulations and improves user comfort.

Correct Installation Matters

Incorrect installation leads to performance issues and safety hazards. Common mistakes include:

• Poor airflow, leading to overheating
• Incompatible remote fuel tanks
• Incorrect wiring of battery chargers and auxiliary systems
• Phase rotation errors affecting power delivery
• Improper earthing causing safety risks
• Loose or inadequate power cable connections
• Incorrectly configured remote start systems
• Backpressure problems in exhaust systems, leading to engine failure
• Using an undersized generator for the required load

Hiring an experienced generator engineer is essential for proper installation. A competent professional will ensure all connections, ventilation, and load requirements meet manufacturer guidelines. Incorrect installations often void warranties and lead to costly breakdowns.

Maintenance and Spare Parts Availability

Even the best generators require regular maintenance. Ensure that spare parts are readily available before purchasing. Check if:

• The manufacturer still produces replacement parts
• Local service providers can repair the generator model
• Routine maintenance costs align with your budget

Neglecting maintenance can reduce a generator’s lifespan and lead to sudden failures during critical times.