Voltage, Phase and Frequency: Getting the Power Supply Right Before You Import a Cold Press

Why power supply is the first question, not the last

A cold press is a motor, a gearbox, a screw and a heating element in a frame. Everything else about the machine — how much seed it takes, how dry the cake comes out, how easy it is to clean — only matters if the machine turns on and stays on at your site.

Every year, buyers import equipment that arrives in perfect condition and then sits in a corner because the workshop has two wires where the machine needs three, or because the only free breaker in the panel is too small to start the motor. The machine is not faulty. The site was never checked.

This guide explains what to check, in what order, and what to send us so we can confirm compatibility before you place an order. Where a number depends on your own building, we show you how to get it rather than guessing it for you.

Single-phase and three-phase in plain terms

Electricity arrives at your building as either single-phase or three-phase power.

• Single-phase is what most homes, small shops and light workshops receive. It is typically two wires that do work — one live and one neutral — plus earth. It is simple, cheap to connect, and adequate for smaller motors.
• Three-phase is what most industrial premises receive. Three live wires deliver power in an overlapping sequence, plus neutral and earth. The motor receives a smoother, more continuous push.

The practical difference for an oil press:

This is why our range splits the way it does. The CSP-5, CSP-10 and CSP-15 are specified for single-phase 220 V, so they can be installed in premises that have ordinary domestic-type supply. The CSP-30 is specified for three-phase 380 V, because a motor of that size runs far better on three phases. A CSP-LINE installation places several presses in sequence, so the loads add together and a three-phase industrial supply becomes the sensible base.

Full electrical figures for each model are on the individual product pages. Read them next to this guide, not instead of it.

“220 V” and “380 V” are nominal, not exact

Grid voltage is a nominal label with a tolerance band around it, and different countries label the same physical system differently.

• Single-phase supplies are commonly labelled 220 V, 230 V or 240 V. In many networks these describe supplies close enough to each other that equipment built for one operates on another — but this must be confirmed for the specific machine, not assumed.
• Three-phase supplies are commonly labelled 380 V, 400 V or 415 V between phases. Again, these often sit within the same practical band, and again it must be confirmed rather than assumed.

Two things follow from this:

1. Do not reject a machine because the label says 380 V and your meter says 400 V. Ask.
2. Do not accept a machine on that basis either. Send us the actual figure from your site and let us confirm it in writing.

Voltage that sits persistently below the machine’s band is the more damaging case. An undervolt motor draws more current to produce the same torque, runs hotter, and fails early. If your supply sags every afternoon, that is information we need before shipment, not after.

Frequency: why 50 Hz and 60 Hz change how the screw turns

Frequency is how many times per second the alternating current reverses direction. It is measured in hertz (Hz). Most of the world runs at either 50 Hz or 60 Hz.

In an ordinary induction motor, the rotation speed is set by the supply frequency. It is not a setting inside the machine. Feed the same motor a higher frequency and it turns proportionally faster; feed it a lower frequency and it turns proportionally slower.

On an oil press, the motor speed becomes the screw speed through the gearbox, and screw speed is a process variable:

• Faster screw — seed passes through the barrel more quickly, spends less time under pressure, and the cake tends to come out wetter with more oil left in it. Throughput rises, extraction quality falls.
• Slower screw — more residence time and more pressure exposure, but reduced output per hour.
• Motor torque and cooling behaviour also change with frequency, so a motor run outside its designed frequency is not simply “a bit faster”. Its thermal margin changes too.

This is why frequency belongs in your very first message to us. Tell us whether your site is 50 Hz or 60 Hz and we will confirm the correct motor specification for your order. Do not order first and ask afterwards.

Regional patterns — useful for orientation, not for ordering

There are broad patterns, and they are worth knowing so you understand what you are likely to find. They are not a substitute for checking your own meter and panel.

• Much of Europe, Africa, South Asia, Southeast Asia, the Middle East and Oceania commonly operates in the 220–240 V, 50 Hz family, with three-phase in the 380–415 V range for industrial premises.
• North America commonly uses 120 V and 240 V at 60 Hz for ordinary premises, delivered in a split arrangement, with different three-phase conventions in commercial buildings.
• Parts of Latin America, the Caribbean, Japan, Korea, Taiwan, the Philippines and Saudi Arabia are mixed or unusual cases — voltage and frequency there do not always follow the pattern of the surrounding region, and can even differ between areas of one country.

Treat all of the above as “what to expect when you go and look”. Utility practice changes, old buildings keep old wiring, industrial estates get different supply from the housing next door, and rented units are often fed from a shared board that limits you further. Measure your site.

Converters and transformers: what they do, and what they cost you

If the supply you have does not match the machine you want, there are options. None of them is free.

Three points buyers routinely miss:

1. A transformer does not change frequency. If you have a 60 Hz supply and a 50 Hz machine, a transformer solves nothing about screw speed.
2. Conversion equipment must be sized for the moment of starting, when a motor briefly draws far more current than it does while running. Ask your electrician or the converter supplier for the starting allowance for your specific motor.
3. Converted power can affect support terms. If you intend to run the machine through a converter, tell us in the RFQ so it is on the record from the start.

Working out the current your site must supply

You need to know whether your existing breaker and cable can carry the machine. Do not guess this — hand the arithmetic to a qualified electrician, and give them the machine’s actual figures from the product page.

Give your electrician:

• The motor power in kW from the model’s spec table.
• The heater power in kW. The heater is a separate load and adds to the motor load when both run together. Size the circuit for both, not for the larger of the two.
• The voltage and phase the machine is specified for.
• The cable run length from your panel to the machine position, in metres. Long runs cause voltage drop and may need thicker cable.
• The ambient temperature of the room, which affects how much current a cable can safely carry.

The relationships they will use are:

• Single-phase: current ≈ power ÷ voltage (adjusted for motor power factor and efficiency)
• Three-phase: current ≈ power ÷ (voltage × √3) (likewise adjusted)

The adjustments are why this is an electrician’s job and not a calculator’s. What you should come away with is a specific answer: the breaker rating and cable size your installation needs, in writing, before the machine ships.

Site survey checklist

Do this once, properly, and most import surprises disappear. Photograph everything — a photograph settles arguments that a description cannot.

1. Photograph the electrical panel with the door open, showing the breakers and any labelling.
2. Count the phases. Look at the main incoming breaker and cable. A qualified electrician can confirm in a minute whether you have single-phase or three-phase; do not rely on the number of wires you think you can see.
3. Measure the voltage with a multimeter: live-to-neutral, and if you have three phases, phase-to-phase as well. Record the readings.
4. Measure again at a different time of day, ideally during your local peak load. Note the lowest figure you see.
5. Record the frequency shown on your meter or measured at the socket.
6. Note the main breaker rating printed on the incoming breaker, in amps.
7. Note the spare capacity. List what else already runs on that panel at the same time — pumps, filters, lighting, refrigeration, filling equipment.
8. Photograph the socket or connection point where the press will be installed.
9. Measure the cable run in metres from the panel to that point.
10. Check the earthing. Confirm with your electrician that a proper protective earth exists at the machine position.
11. Record grid reliability honestly. Outages per week, typical duration, whether you have a generator and its rating.
12. Photograph the room — floor, doorway width, ventilation, drainage. It costs nothing and prevents a second set of problems.

What to send with your RFQ

Paste this into your message to us and fill in the blanks:

• Country and city of installation
• Supply type: single-phase or three-phase
• Measured voltage (and lowest observed voltage)
• Frequency: 50 Hz or 60 Hz
• Main breaker rating in amps
• Other equipment on the same circuit
• Generator: yes or no, and its rating
• Seed or seeds you intend to press
• Target output, expressed as kg per hour or kg per day
• Photographs: panel, connection point, installation room

With that, we can tell you which model fits your supply, whether anything needs to change on our side, and what your electrician needs to prepare before the crate arrives.

Common mistakes worth avoiding

• Assuming the country pattern applies to your building. Industrial estates, rented units and older premises frequently differ from the national norm.
• Sizing the circuit for the motor alone and forgetting that the heater runs at the same time.
• Sizing a generator for running load and discovering it stalls every time the press starts.
• Buying a bigger press than the supply can carry, then trying to solve it with a converter afterwards. Choosing the right model at RFQ stage is always cheaper.
• Ignoring frequency because voltage matched. Voltage and frequency are separate questions and both must be right.
• Leaving it to the electrician after arrival. By then the machine is bought and the options are narrow.

Ask us before you order

Tell us what your site actually supplies and we will tell you what fits. If the answer is that no model in the range suits your current supply, we will say so — that is a better outcome for both of us than a machine that cannot run.

Request a quote with your voltage, phase and frequency details, or send us a seed sample for a press test so you can see the cake and oil from your own material before you commit.

Request a quote