What Power Supply Does a Food Trailer Need in NZ?

The Short Answer

Most food trailers in New Zealand run on 32-amp single-phase power. This is the standard electrical supply available at the majority of NZ markets, events, and trading locations — equivalent to approximately 7,300 watts of usable capacity. It is enough for most coffee trailers, simple food concepts, and mid-range kitchen setups when equipment is planned carefully.

What Is Single-Phase Power?

Single-phase power is the same type of electrical supply used in most New Zealand homes. It runs at 230 volts and connects to a market or event site through a 32-amp lead. The 32-amp rating is your limit — drawing more than that will trip the circuit and cut power to your trailer. To understand how much power you have available, multiply amps by voltage. Thirty-two amps multiplied by 230 volts gives approximately 7,360 watts — your maximum usable capacity on a standard single-phase connection.

In practical terms: 7,300 watts is enough to run a two-group espresso machine, a coffee grinder, a commercial fridge, a water heater, and lighting simultaneously — if your equipment has been planned carefully. Most coffee trailers and many food concepts fit comfortably within this.

What Is Three-Phase Power?

Three-phase power runs through three active wires instead of one and delivers significantly more capacity. For a food trailer, it is only necessary when your total equipment load consistently exceeds what 32-amp single-phase can deliver. This is most common in high-volume operations running multiple large appliances simultaneously — two commercial espresso machines, a large commercial fryer, a bain-marie, and a display fridge all drawing peak load at the same time.

‍The practical problem with three-phase power: Not all markets and events in New Zealand offer it. A trailer that depends on three-phase supply is significantly limited in where it can trade. This is a commercial decision as much as a technical one — discuss it with your supplier before committing to a build.

How Much Power Does Your Concept Actually Need?

The way to answer this question is straightforward: list every electrical appliance you plan to run, find the wattage for each one, add them up, and divide by 230. The result is your total amp draw. Take a coffee trailer as an example. A two-group commercial espresso machine typically draws around 3,200 watts. Add a grinder at 300 watts, an under-bench fridge at 150 watts, an on-demand water heater at 2,400 watts, and LED lighting plus a POS terminal at around 150 watts.

The nameplate total is approximately 6,200 watts — around 27 amps using a simple watts ÷ volts calculation. That suggests a 32-amp supply may be suitable, but the final maximum demand and electrical design should be confirmed by a registered electrician. Now consider a burger trailer using an electric flat-top grill. A commercial electric grill draws around 4,800 watts alone. Add a bun toaster, two fridges, a chip warmer, and a water heater — and you are looking at close to 9,000 watts, or nearly 39 amps. That exceeds the 32-amp limit and requires either three-phase supply, a generator, or a switch to gas cooking to bring the electrical load down.

Write out your full equipment list before you talk to your trailer supplier. Do not leave this step until after the build has started — changing electrical capacity after the trailer is built is costly and avoidable.

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‍The Two Mistakes Most People Make

1. Treating nameplate wattage as the running load

Every appliance has a maximum rated wattage on its label. But most equipment does not run at that wattage continuously. A commercial espresso machine rated at 3,200 watts draws full power only during its heating cycle — most of the time it draws considerably less. A qualified electrician calculates the actual running load, not just the sum of nameplate ratings. This is why the same list of appliances can sometimes fit within 32 amps even when the nameplate total suggests otherwise. Do not attempt this calculation yourself — have it confirmed by a registered electrician or discussed with your trailer supplier as part of the build planning.

2. Designing the trailer before checking the market's power supply

Different markets and events in New Zealand offer different power arrangements. Some provide 32-amp single-phase as standard. Some only offer 15-amp supply — significantly less. Some offer both depending on the pitch. And some have no mains power at all and require all traders to supply their own generators.

‍Before finalising your trailer specification, contact your primary intended trading locations and ask specifically what power supply is available to food vendors. This one question can change your entire build.

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Gas or Electric: Which Is Better for Cooking?

For high-heat cooking — commercial burners, woks, fryers, griddles — gas almost always makes more sense than electric in a food trailer. For high-heat cooking such as burners, woks, fryers and griddles, gas can be a practical option in a food trailer because it reduces demand on your electrical supply. An electric fryer, for example, can consume a significant portion of a 32-amp supply on its own. Using LPG for high-demand cooking can leave more electrical capacity available for refrigeration, water heating, lighting and other equipment.

A gas burner powerful enough to fry at commercial volume draws zero amps from your electrical supply. An equivalent electric fryer can draw 15 to 20 amps alone — potentially more than half your entire 32-amp electrical allowance on a single appliance. Gas also heats faster, reaches higher temperatures, and delivers more consistent performance than electric equivalents at the same price point. The additional requirement is certification — any LPG gas system on a food trailer must be installed and certified by a licensed gasfitter. At Food Trailer Co., gas certification is included in every build. The most practical approach for most NZ food trailers: use gas for high-heat cooking equipment and reserve electrical capacity for refrigeration, water heating, lighting, and lower-draw appliances. This is the configuration used by most experienced food trailer operators in New Zealand.

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Do You Need a Generator?

A generator gives your trailer electrical independence — you can trade anywhere regardless of what power is available on site. Whether you actually need one depends on your concept and trading locations. A generator makes clear sense if you regularly trade at locations with limited or no mains supply, if your electrical load exceeds 32-amp capacity, or if you do private events and corporate functions at non-market venues — farms, rural properties, or private locations. It is less likely to be necessary if you primarily trade at established markets with reliable 32-amp supply and your equipment load sits comfortably within that.

What to consider if you do need one

• Capacity: Size your generator to your peak load plus at least 20 percent headroom. An undersized generator causes voltage fluctuations that can damage equipment.

• Noise: Inverter generators are significantly quieter than conventional generators and are preferred at markets and events. Some markets have noise limits — check before you buy.

• Fuel: Factor in ongoing fuel costs as a regular operating expense from day one.

• Maintenance: Generators require regular servicing. Budget for it from the start and keep a service log.

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Power Leads: What You Need to Know

A 32-amp lead uses a different plug and socket to a 15-amp lead — they cannot be interchanged. Confirm what connection type your primary market uses before buying your lead. Never use a domestic extension lead in a commercial food trailer. Domestic leads are not rated for sustained commercial current draw and present a genuine safety risk. Use only commercial-grade,

RCD-protected leads rated for your load. Keep your leads in good condition. Damaged insulation will fail an inspection and is a safety hazard. Replace any lead showing signs of wear before your next trading day.

All Food Trailer Co. builds include RCD (Residual Current Device) protection on the electrical installation as standard. This is a requirement under the Electricity (Safety) Regulations 2010 and is non-negotiable for any compliant food trailer in New Zealand.

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The Electrical Warrant of Fitness (WoEF)

All commercial electrical installations in New Zealand — including food trailer electrical systems — must be inspected and certified by a registered electrician. This certification is called an Electrical Warrant of Fitness, or WoEF. The WoEF must be renewed periodically — typically every 4 years.

At Food Trailer Co., the WoEF is included in every build. Your trailer leaves our Christchurch premises with the electrical installation already certified and fully compliant. If you modify the electrical system after delivery — adding an appliance, installing additional circuits, or changing the wiring — the modified work must be inspected by a registered electrician and a new WoEF issued before it is used.

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The Six-Step Power Planning Checklist

Work through these steps before finalising your trailer specification.

1. List every electrical appliance you plan to run. Include everything — fridge, water heater, lighting, POS terminal, phone charger — not just the primary cooking equipment.

2. Find the wattage for each appliance. Check the manufacturer's specification sheet or the product label.

‍3. Calculate your total amp draw. Add up total watts and divide by 230. this will give you a rough calculation, for accuracy, use a registered electrician.

4. Contact your primary trading locations. Ask specifically what power supply is available to food vendors — 32-amp, 15-amp, or none.

5. Consider gas for high-heat cooking. Switching from electric to gas cooking can significantly reduce your electrical load and open up more trading locations.

6. Discuss with your supplier before the build. Getting this right at the design stage costs nothing. Getting it wrong costs significantly more to fix.