When you’re heading to festivals, markets, or pop-ups, sooner or later you’ll run into reality: power on site either isn’t available, is expensive, or is weak/unreliable. That’s when a generator. A properly chosen generator gives you freedom, but the wrong one can do the exact opposite—tripped breakers, voltage fluctuations, noise, stress, and in the worst case, a safety issue.
In this article, we’ll show you how to choose a generator for a catering trailer or food truck based on real consumption, which type is suitable for sensitive equipment (coffee machine, refrigeration, beer tap system), and how to set it up to be as quiet and safe as possible.
1) First, clarify: should the generator cover the “basics” or the entire operation?
In practice, there are 2 scenarios:
A) Generator as backup / supplement (semi-off-grid)
- you have 230V on site or a weak hookup,
- the generator covers only part of the equipment (e.g., refrigeration + lights),
- goal: keep things running if something fails or the connection isn’t enough.
B) Generator as the primary source (off-grid events)
- you’re going to an event without a hookup or with limitations,
- the generator has to handle the full menu and peak loads,
- goal: stability, quiet operation, and enough power even during start-ups.
Tip: The more “primary” the generator is, the more it pays to invest in a higher-quality setup and good placement (noise, exhaust, service, safety).
2) Generator output: calculate peaks, not just the nameplate kW
When choosing a generator, it’s not enough to just add up the “power ratings” on the labels.
The right approach:
- Make a list of appliances that may run at the same time.
- Distinguish between:
- running load,
- starting load – a short peak during start-up (compressors, pumps, refrigeration).
- Add headroom (typically 20–30%) so the generator isn’t constantly running at the limit.
The most common power “killers” in a catering trailer or food truck:
- electric heating (fryer, grill, oven, cooktop),
- instant water heating,
- air conditioning,
- compressor refrigeration and freezers,
- some professional coffee machines during heat-up.
Appliance / equipment (TOP) | Running load (kW) | Starting peak (kW) |
1) Commercial fridge (1–2 doors) | 0.30 – 0.80 | 1.5 – 2.5 |
2) Freezer / chest freezer | 0.20 – 0.60 | 1.0 – 2.0 |
3) Ice maker (small/medium) | 0.25 – 0.80 | 1.0 – 2.5 |
4) Espresso machine (1–2 group) | 2.0 – 5.5 | 3.0 – 7.0 |
5) Dishwasher (under-counter) | 2.0 – 3.5 | 2.0 – 3.5 |
6) Instant water heater / 6 L boiler | 1.5 – 9.0 | 1.5 – 9.0 |
7) Extraction / hood | 0.10 – 1.00 | 0.3 – 2.0 |
8) Air conditioning / space cooling | 0.70 – 3.00 | 2.0 – 6.0 |
9) Contact grill / panini press | 1.8 – 3.5 | 1.8 – 3.5 |
10) Electric fryer (single vat) | 3.0 – 6.0 | 3.0 – 6.0 |
3) 230V vs 400V: when do you need a 3-phase generator?
If your equipment is split across multiple circuits/phases, you can distribute the load so you don’t overload a single leg.
At Gastronova, the standard is a 400V 32A CEE connection, split into three circuits (phases). On request, we can also prepare a configuration for 3×230V, depending on the type of operation and the availability of hookups at events.
- A 230V generator is often enough for simpler concepts (lights, refrigeration, beer tap system, some coffee machines).
- A 400V (3-phase) generator makes sense for higher outputs, multiple large appliances, or when you want more stable load distribution.
Recommendation: Diesel generator https://gastronova.eu/produkt/dieslovy-generator/
4) Inverter vs conventional generator: what’s better for catering?
Inverter (“clean power”)
- typically quieter and more fuel-efficient under variable load,
- often better suited for more sensitive equipment (electronics, some control units).
Conventional (traditional)
- often better value in €/kW and robust,
- for sensitive electronics, it depends on the quality of regulation and the specific model.
If you have sensitive gear in your setup (coffee machine, electronic controls, POS, LED systems), an inverter/“clean power” is the safer choice.
Recommendation: Petrol generator https://gastronova.eu/produkt/benzinovy-generator/
5) Generator placement: why we recommend the service area behind the trailer
Even though we offer a generator box, in practice we most often recommend placing the generator in the service area behind the trailer—especially for larger units (especially diesel).
The reasons are simple:
- noise: the generator won’t disturb customers at the serving window,
- exhaust fumes: you reduce the risk of fumes drifting toward staff or customers,
- tow hitch load (drawbar): large generators up front can negatively affect weight distribution and trailer handling; with some large units, it may not even be technically possible.
Summary:
- a box is great for smaller, lighter solutions or specific setups,
- but the default recommendation is the service area behind the trailer (quieter, safer, more practical).
6) Safety: CO, ventilation, and “never in an enclosed space”
Generators produce carbon monoxide (CO). The basic rule: always run the generator outdoors and in a very well-ventilated area, away from windows/doors/vents, and so the exhaust doesn’t blow toward people or into the trailer.
Minimal checklist for a safe setup:
- the generator runs outdoors only,
- enough space around it (intake/exhaust),
- cables sized for the load (no hobby extension cords),
- stable placement (so it doesn’t vibrate and “walk”),
- refuel only after it has cooled down.
7) How we do it at Gastronova: custom electrics + inspection certificate
Electrical systems in a catering trailer or food truck can’t be done “by eye”. Different menus = different appliances = different circuits and load distribution.
That’s why with us:
- we design the electrical wiring to match your concept and specific appliances,
- the design is done by a certified electrician in Slovakia,
- and the electrical installation is then checked and handed over with an inspection certificate.
8) When is it better to go with gas instead of a bigger generator?
If you have large electrical loads (fryer, grill, oven, water heating), it’s worth considering gas alternatives:
- you’ll reduce peak kW demand in the trailer,
- you’ll reduce electricity costs at festivals,
- you’ll increase self-sufficiency.
Sometimes it’s cheaper and more stable to switch one big appliance to gas than to buy a significantly larger generator.
8) When is it better to go with gas instead of a bigger generator?
If you have large electrical loads (fryer, grill, oven, water heating), it’s worth considering gas alternatives:
- you’ll reduce peak kW demand in the trailer,
- you’ll reduce electricity costs at festivals,
- you’ll increase self-sufficiency.
Sometimes it’s cheaper and more stable to switch one big appliance to gas than to buy a significantly larger generator.
Gastronova recommendation
If you want your generator in a catering trailer or food truck to work without stress:
- list of appliances + real operating mode,
- peak-load calculation + headroom,
- decide 230V vs 400V based on your concept,
- place the generator in the service area behind the trailer (noise, exhaust, weight),
- custom-designed trailer electrics with an inspection certificate.
If you want, we can help design the configuration (circuits, connection, generator selection, and a safe setup) so it works in practice at events—and so the tech isn’t what ruins your day.
FAQ – Generator in a catering trailer or food truck
1) What generator do I need for a catering trailer or food truck?
It depends on whether the generator should be a backup (covering only part of the operation) or the primary source (powering everything). The best approach is to make a list of appliances, determine what runs at the same time, include starting peaks, and add headroom.
2) Why isn’t it enough to add up appliance kW “on paper”?
Because some devices have starting peaks (refrigeration, freezers, air conditioning, pumps), and in practice you get overlaps (multiple things switching on at once). If the generator is always running at the limit, voltage will fluctuate or it will trip out.
3) Is a 230V or 400V generator better?
- 230V is often enough for simpler concepts (lights, refrigeration, beer tap system, part of bar equipment).
- 400V (3-phase) makes sense for higher outputs, multiple “heavy” appliances, or if you want to distribute power across phases (more stable operation).
4) Inverter or conventional generator—what’s better?
An inverter (clean power) is usually better for more sensitive equipment and is often quieter under variable load. A conventional generator is robust and often better value in €/kW. The key is choosing based on what you’re powering (coffee machine, electronics, POS, LED).
5) Where should the generator be placed?
In general, we recommend placing the generator in the service area behind the trailer —especially larger diesel units. You’ll reduce noise at the window, limit exhaust fumes near customers, and avoid issues with tow hitch load.
6) What is a generator box good for, and when is it not suitable?
A box is useful for smaller solutions or specific setups (protection, tidiness, cable routing). With larger generators, however, weight, noise, and the need for significant ventilation can be limiting—so the service area behind the trailer is often more practical.
7) Is it safe to use a generator near the trailer?
Yes, if the generator is always outdoors, has sufficient ventilation, and the exhaust is directed away from people and away from the trailer. Never run it in an enclosed space or “in a box without an air supply”.
8) When is it better to choose gas instead of a bigger generator?
If you have large electrical loads (fryer, grill, oven, water heating), it can sometimes be better to switch one big appliance to gas than to buy a significantly more powerful generator. You’ll reduce peaks and increase independence at events.
