CNC MACHINE TOOL POWER REQUIREMENTS AND WHY THEY ARE SO IMPORTANT
05.26.2021
For any machinery to operate efficiently, it needs clean fuel. CNC equipment is no different. The fuel for CNC equipment is electricity that is usually provided by the local utility company.
Electricity is comprised of two components - amps and voltage. Amps are similar to current flow in water, while voltage can be compared to the pressure of the water. You may have also heard the term power when discussing electricity. Power is simply voltage times amps (P=V * I). To operate CNC equipment efficiently, we need clean power with the correct voltage and amperage.
The power requirement for CNC equipment is stated in KVA (Kilo Volt Amps). Okuma historically uses two voltage levels: 200 AC (alternating current) and 220 AC volts. Allowable voltage range is normally +- 10%, including voltage fluctuations resulting from load. On a system designed for 200 volts after the transformer, this would be mean voltage range could be between 180 Volts and 220 Volts. Keep in mind, most utility companies can vary the voltage supplied +- 10%. Don’t create an overvoltage situation by installing a transformer that fails to drop the voltage low enough to accommodate this fluctuation.
Amperage level depends on the requirement of the equipment given in KVA. The KVA rating for your Okuma machine tool can be easily obtained by contacting your local Okuma distributor.
Special thanks to Richard Jordan, Principal Engineer, Okuma America Corporation, for providing this article.
A few best practices when setting up power for new or existing Okuma:
- Match the KVA rating supplied as close as possible to the machine KVA rating, while never going under the KVA rating. Transformer KVA rating should match as close as possible also.
- Use the correct wire size as recommend by local code for the current being supplied.
- Stay away from welders or other equipment that may cause electrical “noise” on the power supply bus.
- Most importantly, always use licensed electricians to help with running power to a CNC machine tool.
