KB Electronics KBWT-210 User Manual
KB Electronics Software
KBWT Series Installation and Operation Instructions
(A40130) – Rev. B00 – 5/29/2013
Page 1 of 7
INSTALLATION AND OPERATION INSTRUCTIONS
KBWT SERIES
These Installation and Operation Instructions
Cover Models KBWT-16, 26, 110, 112, 210
RoHS
SAFETY WARNING, ON PAGE 7, MUST BE READ AND UNDERSTOOD BEFORE PROCEEDING!
 
 
1 DESCRIPTION 
Thank you for purchasing the KBWT Series Pulse Width Modulated (PWM) Adjustable Speed DC Drive. 
KB Electronics, Inc. is committed to providing total customer satisfaction by providing quality products that are 
easy to install and operate. 
Several models are available that provide the user a choice of input voltage and output current. The drives are 
designed to operate Permanent Magnet (PM) DC motors rated 0.75 HP (0.5 kW) thru 2.2 HP (1.7 kW) continuous 
duty and 1.5 HP (1.1 kW) thru 4.0 HP (3.0 kW) intermittent duty. 
The drive provides excellent dynamic response to load variation. The efficient PWM waveform produces an 
almost pure DC current to the motor (form factor < 1.05), which has several advantages over a conventional SCR 
control. PWM significantly lowers audible motor noise and provides longer brush life. It also produces less motor 
heating, allowing a smaller and less costly motor to be used for most applications. Another advantage of PWM is 
higher output voltage, which provides increased output speed. In addition, pulse-by-pulse current sensing 
provides short circuit protection and prevents control damage due to shorted motors. 
A unique feature of the drive is its active bridge, which provides a substantial reduction in AC line surge current 
each time the control is turned on. This prevents nuisance tripping of the circuit breaker and allows the control to 
be turned on or off rapidly without damage to critical components. The drive also contains a built-in safety circuit 
that will shut down the control if the main power transistor short circuits. This prevents high-speed runaway, 
a potential problem with competitors’ controls. 
The drive utilizes heat-spreader construction. This system provides an enhanced thermal path that eliminates 
overtemperature cycles which cause premature failure of the power transistor. Other features of the drive are 
Timed Current Limit (TCL) motor burnout protection (I x t), which will shut the control down if the motor is 
overloaded for a predetermined time and the Potentiometer Safety Circuit™ (PSM), which prevents the control 
from starting when the AC line is applied unless the signal input is reset to zero. Diagnostic LEDs for Power On 
(PWR) and Overload (OL) indication are also provided. The drive contains barrier terminal blocks as standard or 
quick-connect terminals for OEM applications. A 5 kΩ Main Speed Potentiometer (supplied), an isolated analog 
input signal (0 – 5 Volts DC), or an isolated Pulse Width Modulated (PWM) signal from a microprocessor can be 
used to control motor speed. 
STANDARD FEATURES 
• Short Circuit Protection: Pulse-by-pulse current sensing provides short circuit protection and prevents control 
 damage due to shorted motors. 
• Timed Current Limit (TCL): Electronic Motor Burnout Protection (I x t) will trip the drive if an overload condition 
 persists for a predetermined time of 3 seconds (factory setting), 5 seconds, or 10 seconds. 
• Status Indicator LEDs: Power On (PWR) and Overload (OL). 
• Active Bridge: Provides controlled AC line inrush current limiting. 
• Power Transistor Short Circuit Runaway Protection: Will shut down the control if the main power transistor 
 short circuits. 
• Heat-Spreader: Eliminates overtemperature cycles which cause premature failure of the power transistor. 
• Adjustable Trimpots: Current Limit (CL), IR Compensation (IR), Maximum Speed (MAX), Minimum Speed 
 (MIN), Acceleration (ACCEL), and Deceleration (DECEL). 
• Potentiometer Safety Circuit: Prevents startup with the AC line unless the signal input is set to zero. 
• Barrier Terminal Blocks: Facilitate wiring of the AC Line input, motor armature, motor field (shunt wound 
 motors only), and signal inputs. 
• Quick-Connect Terminals: Used to connect an Inhibit switch or contact. 
• Armature Fuse: Models KBWT-16, 26 contain a 10 Amp fuse, Models KBWT-110, 210 contain a 15 Amp fuse, 
 and Model KBWT-112 contains a 20 Amp fuse.