This guide covers the core safety practices for generator field work. It does not replace site rules, the equipment maker’s instructions or local regulations, but it sets out the habits that keep technicians safe on every job.
Risk assessment and permits
Every job should start with a risk assessment that considers the task, the equipment, the site and the people involved. Many sites require a permit to work, especially for electrical isolation, hot work or confined spaces. Read the permit conditions and confirm them on site before starting.
If conditions change during the job, such as weather, additional tasks or a change in the site’s power situation, stop and reassess.
Automatic start risks
Standby generators are designed to start automatically when mains power fails or when a test timer runs. A technician working on a set that starts unexpectedly faces serious injury from fans, belts and moving parts. Before any work, switch the controller to off or manual, isolate the starting batteries and apply locks and tags.
Confirm with the site that no one else will reset the system while work is in progress.
Isolation and lockout
Isolation covers all energy sources: the starting circuit, the alternator output, the mains supply through the transfer switch, battery chargers, heaters and any parallel sources. Each isolation point should be locked and tagged by the person doing the work, with their own lock.
Prove isolation by testing for absence of voltage with a suitable tester before touching conductors. Test the tester before and after use.
Electrical hazards and arc flash
Generators produce voltages that can kill, and faults can release arc flash energy that causes severe burns. Work on live equipment should be avoided wherever possible. When live work is unavoidable, such as some testing and fault-finding, follow the site’s procedures and wear arc-rated clothing and face protection suited to the hazard level.
Only qualified, authorised technicians should work on electrical systems.
Rotating parts
Fans, belts, pulleys, flywheels and couplings can catch clothing, hair or hands. Guards must be in place whenever the engine runs. If a guard must be removed for inspection, the engine should be stopped and isolated first.
Never reach into a running engine to make an adjustment. Loose clothing and jewellery should not be worn near machinery.
Hot surfaces and pressurised coolant
Exhaust manifolds, turbochargers and exhaust pipes reach temperatures that burn skin instantly. Allow the engine to cool before working near these parts. Coolant systems are pressurised when hot; opening a radiator cap on a hot engine can release scalding coolant.
Wait for the system to cool and release pressure slowly, using gloves and eye protection.
Fuel and fire
Diesel fuel is less volatile than petrol but still burns, especially as mist or when heated. Fuel leaks onto hot surfaces are a common cause of generator fires. Clean up spills promptly, keep ignition sources away and make sure fire extinguishers are available and in date.
Hot work, such as welding or grinding near fuel systems, needs a hot work permit and fire watch.
Batteries
Starting batteries contain acid and can produce hydrogen gas, which is explosive. Avoid sparks near batteries, disconnect the negative terminal first and reconnect it last, and wear eye protection. Batteries are heavy; use proper lifting techniques.
Dispose of old batteries through approved channels.
Noise and fumes
Running generators produce noise levels that damage hearing quickly. Wear hearing protection whenever the engine runs. Exhaust fumes contain carbon monoxide, which is invisible and odourless. Never run a generator in an enclosed space without proper ventilation and exhaust routing.
If you feel dizzy, nauseous or develop a headache while working near a running set, move to fresh air immediately.
Lifting heavy components
Cylinder heads, turbochargers, alternator parts and batteries are heavy. Use lifting equipment rated for the load, check its certification and plan the lift. Never stand under a suspended load.
Our page on preventive maintenance visits describes the routine tasks where lifting often comes up.
Remote and lone work
Technicians at remote sites may be hours from help. Before travelling, share the job plan, location and expected return time with a supervisor. Carry communication equipment that works at the site, a first aid kit and enough water. Check in at agreed intervals.
Our page on remote-site technicians explains how field teams are supported on distant jobs.
Personal protective equipment
Basic protective equipment for generator work includes safety boots, eye protection, hearing protection, gloves suited to the task and clothing that does not catch in machinery. Electrical work may require insulated gloves and arc-rated clothing. Check equipment before each job and replace anything damaged; protective gear only helps when it is in good condition and actually worn.
Handover after work
At the end of the job, remove tools and materials, refit guards, remove locks and tags in the correct order, and return the set to automatic mode only after confirming with the site. Record the work done and any defects found.
A clear handover protects both the next person to work on the set and the site that depends on it. Our full range of field technician services follows these practices on every visit.
About the authors
This guide was written by our field service supervisors, who lead generator technicians on mines, utility sites and industrial plants. USP&E employs and directs those technicians as the O&M contractor, never as a broker, with 150+ power projects in 45+ countries, 25,000 MW contracted since 2002 and 24+ years in the field. Our service model is described on the operations and maintenance page.
Offices: Colorado Springs (1755 Telstar Dr, Suite 300), Knoxville (800 S Gay St, Suite 700), London (162-168 Regent Street), Johannesburg (22 Kildoon Rd, Bryanston), Cape Town (31 Brickfield Road, Woodstock) and China (No. 1 Ningzhou Road, Wuxi). Regions: USA | AFRICA | UK | UAE | CHINA. ISO 9001 and ISO 45001 certified.
Field safety questions
Why must standby generators be isolated before work?
They can start automatically when mains fails or a test timer runs. Isolating the controls and batteries prevents unexpected starts.
What energy sources need isolation on a generator?
The starting circuit, alternator output, mains supply through the transfer switch, battery chargers, heaters and any parallel sources.
Is it safe to open a radiator cap on a hot engine?
No. Coolant is pressurised when hot. Wait for the system to cool and release pressure slowly.
How should lone technicians stay safe at remote sites?
Share the job plan and return time, carry working communications and first aid, and check in at agreed intervals.
Book a field technician
Tell us your site, equipment and the work needed, and we will plan a safe service visit with qualified technicians.
Phone +27 10 822 2324 during office hours, or write to info@uspeglobal.com at any time; the field service request form also routes straight to our project engineers. Replacement sets are listed in our diesel generator inventory.