/Products/VFD's & Soft Starters/KB Electronics/KBPB/KBPB-125 KB Electronics "Cycler" Solid State DC Motor Speed Controls, 115VAC
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Product ID: KB8900

KBPB-125 KB Electronics "Cycler" Solid State DC Motor Speed Controls, 115VAC

MFG: KB Electronics, Inc
MFG Part Number: 8900

Available Stock: 3
Selected accessories will also be added to cart
$226.10 / Each
0.75HP, 12.0 Amps Max (without Heatsink)
Select any of the accessories below to purchase them with this inventory item:


The KBPB™ “cycler” control is designed to provide antiplug “instant” reversing, solid state dynamic braking and rapid cycling. It combines all of the features of the KBMM™ speed control with the features of the KB APRM®. Contact arcing is eliminated since the APRM® allows armature switching to take place only when current levels are near zero. The KBPB contains a built-in barrier terminal block and its compact size makes the control ideal for installation where space is at a premium

All models are equipped with KB's exclusive Plug-in Horsepower Resistor® (sold separately). It eliminates the need for recalibrating IR Comp and Current Limit when the control is used on various horsepower motors. The basic ratings of the controls are enhanced with the addition of KB's Auxiliary Heat Sink. The controls also contain Inhibit™, which allows for electronic switching of the armature voltage, and Auto Inhibit®, which provides rapid, safe switching of the AC line.

The controls can be used to drive all PM and Shunt Wound DC motors from zero to full speed by three separate methods: a 5K remote speed pot, an auxiliary speed pot (S4 terminal), or voltage following. If the control is to be operated in a voltage following mode, an isolated analog signal (0-9VDC) is applied to the input terminals P2 (+) and F (-). Adjustment trimpots are provided for MIN, MAX, IR COMP, CL, ACCEL and DECEL.

General Specifications

Manufacturer KB Electronics
Nidec Motor Corporation
Part Number 8900
Model Number KBPB-125
AC Line Input 115 VAC +/-15 %
Single Phase
Motor Voltage 0 to 90 VDC
Rating without Auxiliary Heatsink 12.0 Max AC Load Current (RMS Amps)
8.0 Max DC Load Current (Avg. Amps)
0.75 HP (0.6 kW) Maximum
Rating with Auxiliary Heatsink 24.0 Max AC Load Current (RMS Amps)
16.0 Max DC Load Current (Avg. Amps)
1.5 HP (1.1 kW) Maximum
Shipping Weight 1.9
UPC 024822089005
Warranty 18 Month Limited Warranty

Standard Features

  • Plug-in Horsepower Resistor® (sold separately)
  • Built-in AC Line Fuse (included)
    Armature Fuse (sold separately)
  • Trimpots: MIN, MAX, IR, CL, ACCEL, DECEL and Aux. Speed
  • Auto Inhibit®, Inhibit™ and Enable
  • MOV Transient Protection
  • CL LED Indicator
  • Power/On LED Indicator
  • Voltage Following
  • Tachometer or Armature Feedback
  • Barrier Terminal Block
  • Dynamic Braking Resistor


Speed Range (Ratio) 50:1
Load Regulation (0 – Full Load, 50:1 Speed Range) 1% Base Speed
Line Voltage Regulation (At Full Load, +/-15% Line Variation) 1/2 % Base Speed
Control Linearity (Speed vs Dial Rotation) 2%
CL/Torque Range 0 – 200 % Full Load
ACCEL/DECEL Time Range 0.2 – 10 Seconds
MIN Speed Trimpot Range 0 – 30 % Full Speed
MAX Speed Trimpot Range 50 – 110 % Full Speed
IR Compensation Range 0 – 24 Volts
Max Ambient Temperature 40°C
Maximum Number of Starts/Stops/Reversals 10 Operations/Min
Tachometer Feedback Input Voltage 7V per 1000RPM


Motor Type: the KBPB is designed for Permanent Magnet (PM) and Shunt Wound DC motors. Controls operated on 120VAC inputs are designed for 90V SCR rated motors. Controls operated on 240VAC inputs are designed for 180V SCR rated motors. Use of higher voltage motors will result in degradation of full speed performance. Also, if the motor is not SCR rated, the actual AC line amperage at full load should not exceed the motor's DC nameplate rating.

Torque Requirements: When replacing an AC induction motor with a DC motor and speed control, cosideration must be given to the maximum torque requirements. The full load torque rating of the DC motor must be equal to, or greater than that of the AC motor.

Acceleration Start: The KBPB contains an adjustable acceleration start feature which allows the motor to smoothly accelerate from 0 to full speed over a time period of 0.2 to 10 seconds. The "ACCEL" is factory set at 1 second

Limitations of Use: The KBPB controls are designed for use on machine applications.

Switching Applications: The KBPB contains the KB APRM, which is designed to provide anti-plug instant reverse, solid state dynamic brake and rapid cycling. The maximum recommended number of run-brake cycles is 10 per minute.

  • Back Gauges
  • Door Openers
  • Feeders
  • Indexers
  • Robotics
  • Tapping Machines
  • Pumps
  • Screen Presses
  • Conveyors

Plug-In Horsepower Resistor Chart

Armature Voltage
90 – 130 VDC
Armature Voltage
Resistance Value
Part Number
1/100 - 1/50 1/50 - 1/25 1.0 9833
1/50 - 1/30 1/25 - 1/15 0.51 9834
1/30 - 1/20 1/15 - 1/10 0.35 9835
1/20 - 1/12 1/10 - 1/6 0.25 9836
1/12 - 1/8 1/6 - 1/4 0.18 9837
1/8 - 1/5 1/4 - 1/3 0.1 9838
1/4 1/2 0.05 9839
1/3 3/4 0.035 9840
1/2 1 0.025 9841
3/4 1.5 0.015 9842
1* 2* 0.01 9843
1.5* 3* 0.006 9850

* Auxiliary heatsink must be used to achieve HP Rating