Frequently Asked Questions

Frequently Asked Questions

Motor Replacements and Parts

Q: How Do I Differentiate a Standard KB Electronics Part Number and an OEM Specific Part Number?

A: More specifically, how do I differentiate a standard KB Electronics product part number, that is available through distribution and a KB Electronics Original Equipment Manufacturer (OEM) specific part number that you need to purchase from that particular OEM?

The KB Electronics part number of your drive is on the nameplate. It is usually the number preceded by either "Part Number" or "P/N" depending on the footprint of the unit. If the drive is available from your local distributor, the range of numbers will vary between the numbers 8000 and 10000, or H9000 and H9999. If not, you will need to contact the equipment manufacturer for a replacement drive. Find out more about our complete line of AC Drives (Inverters) and DC Drives. If you have any questions, feel free to contact us online or call us Toll Free at (800) 221-6570.

Q: How Does Using a Variable Speed Drive Reduce Energy Consumption?

A:  Installing a variable speed drive allows direct control of the motor output speed to meet the application demands. As the speed is reduced, the power required decreases. By operating the system at the lowest possible speed required for the application, energy consumption is reduced.  For example, at 80 percent speed, only 51 percent of full load power is required to drive a pump or a fan. 

View our entire line of AC Drives

Q: What is Motor Overload Protection?

A:  KB’s AC drives contain Motor Overload Protection (I²t) with RMS Current Limit (CL). The I²t function provides overload protection and prevents motor burnout. KB’s AC drives are UL approved as an electronic overload protector for motors. With I²t, if the motor is overloaded to 120% of the motor nameplate rating, the I²t timer will start, triggering the drive to trip in 30 minutes. As the motor continues to experience an increase in load, the time it takes the drive to trip decreases. Finally, if the motor is overloaded to 160%, the drive will trip in six seconds. The CL factory settings are for a maximum overload of 160%, limiting the motor current and torque. Some drive manufacturers do not have the current limit feature. During an extreme overload the I²t time is very short, which will cause an undesirable nuisance trip.

Q: NEMA 1 Enclosure Versus a NEMA 4X Enclosure?

A:  NEMA enclosures, in general, are designed to prevent electrical shock by protecting the user from incidental contact with the components contained within. KB’s NEMA 1 drives provide a degree of protection against falling dirt. They are equipped with knockouts for standard electrical fittings. KB’s NEMA 4X drives are constructed with a rugged die-cast aluminum enclosure with a hinged cover. They offer watertight integrity, which makes them ideal for harsh washdown indoor or outdoor applications. They are equipped for use with liquidtight electrical fittings.

Q: What is Under Voltage Protection?

A:  If the AC line voltage falls below specifications the drive cannot maintain the rated torque or power requirements. To prevent damage to the motor, the drive will shut down. When the voltage returns to a safe limit, the drive, depending on presets and programming, will automatically restart or may require a manual restart.

Q: Can KB's AC Drives Operate with GFCI?

A:  GFCI’s will trip when used with most AC Drives.  KB’s AC Drives contain special software to allow them to operate with GFCI circuits. This is a standard feature on our Digital AC Drives and optional, with factory programming, on all AC Hybrid Drives.


Q: What Does the Letter Mean After the Part Number? I Ordered Part Number 9429A and got 9429L.

A:  The revision level does not change the form, fit or function of the control. The letter at the end of the 4 or 5-digit KB part number is a revision level used in the factory, (i.e., KB model KBIC-120 is KB part number 9429L). The revision level is subject to change whenever any upgrades or component changes are made to our controls.

Q: What is a Hybrid Drive™?

A:  KB is the first manufacturer of variable frequency drives to apply the term “Hybrid Drive” to a segment of their AC drive line. A hybrid, by definition, is the merging of two technologies. The drive merges the digital technology of the microprocessor with an easy to use analog interface. Simple trimpot adjustments and selectable jumpers are used in lieu of complicated programming. Hybrid Drives, unlike Digital Drives, require less set up time and are easy to install and operate. Learn more about our Hybrid Drive products.

Q: Where Can I Purchase KB Electronics Products?

A:  KB designs and manufactures more than 200 control models to serve the fractional to 5HP market. For standard controls, all sales must be processed through an authorized distributor. You can find a local distributor by using the distributor locator on our website. 
For OEM applications, KB will provide a custom control that is Ready to Use “Out-of-the-Box”.  Contact our Sales Department for custom drive requirements.

Q: What is the Difference Between KB's Plug-In-Horsepower Resistor® vs. the Competitor's Fixed Resistor?

A:  The PHR allows you to cover the broadest possible horsepower range of motors with one DC Drive. For example, the KBMM-125 DC Drive will control motors from 1/100 HP to 1-1/2 HP; the KBMM-225 DC Drive will control motors from 1/50 HP to 3 HP. By selecting the correct PHR, for your motor, you will not have to waste time calibrating the IR and CL compensation circuits. Our competitors' controls that have fixed horsepower resistors, only have a range from 1/8 HP to 1 HP. 
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