Variable Frequency Drive – KBAC AC Drive

Nexus Grinders and Knife Supply is an authorized Canadian re-seller of KB Electronics Variable Frequency Drives. We ship only within Canada.

How a VFD works

Variable Frequency Drives (VFDs) give variable speed to 3-phase AC induction motors. To use a VFD you must use a 3-phase motor — you can’t run a single-phase motor on the industry-standard VFDs that most knife makers use. A VFD converts single-phase 115 or 230 volt input into 3-phase output to the motor, controls speed, and (with an optional switch) allows forward and reverse.

You can’t use a motor rated higher than the VFD. You can use a higher-rated VFD with a lower-rated motor — for example, a 2 hp VFD (KBAC-27D) with a 1 to 2 hp 3-phase motor. Don’t pair a 1 hp VFD (KBAC-24D) with a 1.5 or 2 hp motor.

Which KBAC drive do you need?

The three drives below are generally used for 1 to 3 hp 3-phase motors:

  • KBAC-24D — recommended for 1.0 hp 3-phase motors.
  • KBAC-27D — recommended for 1.0, 1.5 & 2 hp 3-phase motors; most commonly used for 1.5 and 2 hp.
  • KBAC-29 (1P) — recommended for 2.0 & 3 hp 3-phase motors.

KBAC Hybrid Drive™ — NEMA 4X / IP65

The KBAC series consists of six inverter models rated for 1/8 to 5 hp motors. They are housed in heavy-duty NEMA 4X / IP65 die-cast aluminum washdown/watertight enclosures for indoor or outdoor use. Hybrid drives are digital drives with an analog interface. Warranty is 18 months from the date of purchase.

Optional add-ons include an On/Off AC line switch, a Forward-Stop-Reverse switch, a Run-Stop-Jog switch and strain-relief fittings.

References: KBAC Data Sheet · KBAC Manual. If you’re looking for other KB Electronics drives such as the KBAC-29 (1P), or have questions, please contact Nexus Grinders. We also sell 3-phase motors for your VFD.

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Frequently asked questions

Which KBAC drive is right for a 2 hp motor?

The KBAC-27D handles 1.0, 1.5 and 2.0 hp 3-phase motors and is the usual choice for 1.5 and 2 hp builds. For 2 to 3 hp, the KBAC-29 (1P) is recommended. The KBAC-24D is limited to 1.0 hp.

Can I use a single-phase motor with a KBAC drive?

No. KBAC drives output 3-phase power, so they require a 3-phase motor. They take single-phase 115 or 230 volt input and convert it to 3-phase for the motor.

What does the NEMA 4X / IP65 rating mean?

It means the drive is sealed in a washdown/watertight, corrosion-resistant enclosure — it keeps grinding dust and moisture out, which is exactly what you want in a grinding shop. All KBAC drives carry this rating.

Can I add forward and reverse to the drive?

Yes. The KBAC drives accept an optional Forward-Stop-Reverse switch, along with an On/Off AC line switch and a Run-Stop-Jog switch.

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