Why the voltage notice is there
Some of the power equipment we sell, including flex shafts, polishers, ultrasonic cleaners, steam cleaners, and pickle pots, is designed for one specific supply voltage and cannot be safely used on the other. Running a 110V / 120V unit on a 220V / 240V supply, or plugging a 220V / 240V unit into a 110V / 120V outlet, can damage or destroy the motor, create a fire hazard, and will void the manufacturer warranty. We flag the required voltage on affected product pages so you can verify your bench setup before the unit ships.
The three voltage labels you will see
You may notice that equipment specs, outlet markings, and product listings use slightly different numbers for what are really just two supply types. Here is a quick reference:
120V / 240V — The precise nominal voltages defined by utility standards. Appears in electrical codes, wiring diagrams, and technical blueprints.
115V / 230V — The voltage you will read on most motor nameplates and appliance spec labels. Appears on motor specs, UL/CE data plates, and many imported equipment labels.
110V / 220V — Casual shorthand that has been in common use for decades. Appears in everyday conversation, older manuals, and many online listings.
All three pairs refer to the same two supply types. We use 110V / 120V and 220V / 240V on our product pages as a combined shorthand that covers all three variants at once, so neither label is technically wrong for your outlet.
United States supply reality: Most North American households and shops run 120V single-phase on standard 5-15 outlets (the ones with two slots and a ground). True 240V supply is available at dedicated circuits such as dryer outlets, kiln circuits, and some compressor receptacles. If you are not sure what your outlet delivers, a basic outlet tester or a multimeter set to AC voltage will tell you in seconds. When in doubt, ask a licensed electrician.
What "voltage-select" means on a product page
Some manufacturers sell the same tool in separate 110V / 120V and 220V / 240V versions as different SKUs or variants. On product pages where you see a voltage option in the selector, choose the version that matches your supply before adding to cart. The warning strip above the product description updates to reflect your selection. Once you choose a voltage variant, the strip will confirm the specific requirement for that version.
Warranty and voltage mismatch
Using a unit on the wrong voltage supply is not covered under any manufacturer warranty we are aware of, and Otto Frei cannot file warranty claims for damage caused by incorrect voltage. Before powering on any piece of electrical equipment from us:
- Confirm the voltage marked on the unit's nameplate or power label.
- Confirm the voltage your outlet delivers (120V standard receptacle, or 240V dedicated circuit).
- If the numbers do not match, do not power the unit on. Contact us and we can help you identify an appropriate step-up or step-down transformer, or exchange for the correct voltage variant if one is available.
Transformers and voltage converters
If your bench runs 110V / 120V supply but you have a specific piece of equipment that requires 220V / 240V (or vice versa), a properly rated step-up or step-down transformer is the correct solution. The transformer must be rated at least 20% above the wattage of the equipment you are powering to handle motor start-up draw. We do not currently stock transformers, but any industrial electrical supplier can size one for your application.
Still have questions?
Contact us at [email protected] or call us at 1-800-772-3456. We are happy to help you confirm whether a specific piece of equipment will work with your shop's supply before you order.