High Airflow 240V Compressor

High Airflow 240V Compressor

This is the AF430.

Developed by McMillan Air Compressors to answer the need for a high capacity single phase compressor, the AF430 is the biggest readily available, high pressure, 240V compressor in our market.

Using an Italian made ABAC pump it displaces 489 l/min with a maximum working pressure of 160p.s.i.

It’s the ideal solution for the demanding truck workshop or small factory. Pressure is regulated by McMillan’s NEMAC pressure controller and switching is provided by means of heavy-duty TECO electromagnetic contactors.

AF430 has saved many customers money that they would have spent on upgrading to a 415V supply in order to run a large compressor. It simply requires a dedicated 240V electrical circuit protected by a 20A circuit breaker. In most factories and on most farms this power source is readily available. The compressor is supplied with a large 3-pin plug that can be connected to a 20A wall socket, or it can be permanently wired into a dedicated line.

In the rural environment where 480V SWER (Two Phase) power is available, the AF430 can be supplied, wired for this power source. For more information on this, see:

Sizing a 240V compressor.

Due to the restraints of 240V power the idea of selecting a 240V compressor to fit your requirements was a bit of a limited exercise up until now. The AF430 has changed this.

These limitations played out like this:

1. Do you have a 15A power outlet? No. Well then your choice is 10A or nothing!
2. Do you have 15A outlet? Yes. Now you can go up one size to a 15A compressor which will give about 38% more flow than a 10A compressor.

Since McMillan have developed the AF430, a 3rd option has appeared with the added benefit of high pressure. Hence:

3. Do you have 15A outlet? Yes. You can go up to the 20Amp AF430 compressor which will give you 80% more air than a McMillan 10A compressor and 274% more than some of the cheapy 10A units in the market.

This is possible since most 15A wiring is of a gauge big enough to carry higher amperage, so a larger 240V motor can be powered, by protecting the circuit with a 20A circuit breaker, and dedicating it to the compressor.

How much flow is enough?

Compressed air equipment uses compressed air at various rates dependent on the size and design of the equipment. Rotary tools like grinders and drills use air like water running over a waterwheel to give them their rotary motion. Expanding this analogy, the more water flowing the more power would be available, and the bigger the wheel that could be driven. In the same way a compressor producing high flow will be able to do more work than a smaller, lower flow capacity unit.

The flow rate of a compressor is proportional to the power of the motor/engine driving it. So compressor sizing is all out HP/kW and has little to do with the size of the tank. Common units of flow relating to air compressors are CFM (cubic foot per minute) or L/min (litre per minute) but could be expressed as any unit of volume by time. Tool and equipment manufacturers specify an air flow requirement on their equipment and a recommended working pressure. While the correct pressure is important for efficient operation of the tool, as a general rule, insufficient pressure only presents itself if airflow is insufficient – hence the pressure drops as soon as the required flow is not sustained. This happens if the compressor is too small (not producing enough airflow) for the requirement. It is important when selecting a compressor to match the requirement that you also consider the duty cycle of the compressor. Typically, a piston compressors’ duty cycle should not exceed 60%. Also important is to ensure adequate ventilation for cooling, while observing the recommended oil change out periods.

Data on air tool requirements: Air Usage. Note that 25% usage factor has been applied to these figures.

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