Generator selection for construction site
Proper selection of a generator for a construction site is key to work continuity, safety and cost optimization. Below we present the most important aspects to consider.
Determine actual power demand
The first step is to determine which devices will be powered simultaneously. On a construction site, these are most often:
- concrete mixers
- power tools
- compressors
- welding machines
- pumps
- social and office containers
- construction site lighting
Consider:
- • rated power of devices (kW),
- • starting currents (especially motors, compressors, welding machines),
- • the fact that not all devices work continuously, but may start at the same time.
In practice, the generator should have a power reserve of 20–30% relative to calculated demand.
Pay attention to load characteristics
Construction sites are dominated by inductive and dynamic loads, which are much more demanding than office loads. Key issues:
- high starting current of motors,
- variable load over time,
- short-term overloads.
Therefore, a construction site generator:
- • should have adequate power reserve,
- • should not work constantly at the limit of capacity,
- • must be selected not only "for the sum of kW", but also for work dynamics.
Single-phase or three-phase?
This is a common mistake on construction sites.
Single-phase generator (230 V)
Works well with small tools and light facilities.
Three-phase generator (400 V)
Necessary for larger machines, welding machines and expanded construction facilities.
Important:
With three-phase generators, ensure even phase loading to avoid voltage drops and failures.
Mobility and working conditions
Construction site is a demanding environment:
- • dust, dirt, moisture
- • variable temperatures
- • frequent equipment relocation
Therefore, a construction generator should:
- • have weather-resistant housing,
- • be adapted for continuous operation,
- • have overload and thermal protection.
Fuel, operating time and service
Most often on construction sites, diesel generators are used, due to:
- • lower fuel consumption
- • greater durability during long operation
- • better fuel availability
When selecting, it is worth checking:
- • tank capacity,
- • operating time at 75% load,
- • service and parts availability,
- • possibility of continuous operation (prime power).
Most common errors in generator selection for construction
- selection "on the edge", without power reserve,
- not considering starting currents,
- powering welding machines from too small generator,
- lack of phase load control,
- choosing "universal" generator instead of construction one.
Summary
Selection of a generator for construction site should be based on:
- • actual power demand
- • load characteristics
- • working conditions
- • operating time and service availability
Well-selected generator means work continuity, lower failure risk and real savings during project implementation.
Not sure which generator will be suitable for your construction?