Need site trailer support?

Generator Sizing Guide for Office Trailers

Right-size your generator to your trailer load. Three tiers cover everything from a single PM office to a multi-trailer construction campus. All units are towable diesel generators with integrated fuel containment and 24-hour tanks.

Towable diesel generator for construction office trailers

Choose Your Tier

Each tier matches a common construction site configuration. Click through for full specs, use cases, and FAQ.

Sizing Rule of Thumb

Size to 70-80% of generator capacity for optimal efficiency and fuel economy. Running a generator at full load continuously increases fuel consumption and accelerates wear. Office trailers need 220V single-phase, 100-amp service minimum. If your load is borderline between two tiers, go up — the fuel savings from running at 60-70% capacity will offset the slightly higher rental cost.

Side-by-Side Comparison

Key specifications across all three generator tiers.

Specification 20-25 kW 30-40 kW 50+ kW
Prime Rating 20 kW / 25 kVA 30-36 kW / 36-45 kVA 56 kW / 70 kVA
Standby Rating 22 kW / 27.5 kVA 40 kW / 50 kVA 62 kW / 77 kVA
Voltage 120/240V 1-ph; 208-480V 3-ph 120/240V 1-ph; 208-480V 3-ph 120/240V 1-ph; 208-480V 3-ph
Fuel Diesel Diesel Diesel
Noise Level ≤60 dBA ~66 dBA ~65 dBA
Fuel Tank Integrated 24-hr with containment Integrated 24-hr with containment Integrated 24-hr with containment
Best For Single office trailer Office + breakroom or 2 trailers Multiple trailers, complexes

Built for Construction Sites

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WhisperWatt Quiet Operation

Multiquip WhisperWatt enclosures keep noise levels at 60-66 dBA across all tiers. Meets municipal noise ordinances and keeps your office trailer usable for phone calls and meetings during generator operation.

Integrated Fuel Containment

Every generator includes an integrated 24-hour fuel tank with built-in secondary containment. No separate drip tray or containment berm required for the generator itself. Simplifies SPCC compliance on your site.

Voltage Switchable

All units switch between 120/240V single-phase and 208-480V three-phase configurations. Handles standard office trailer 220V service and three-phase equipment loads from the same generator.

Not Sure Which Generator You Need?

Tell us your trailer count, HVAC tonnage, and any breakroom appliances. We will size the right unit and deliver it connected and running.