OEM Resistive Load Banks

Overvoltage Solutions for AC DrivesOvervoltage Solutions for AC DrivesOvervoltage Solutions for AC DrivesOvervoltage Solutions for AC DrivesOvervoltage Solutions for AC Drives

M3775RK

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Bonitron M3775RK Braking Resistors offer resistive load banks to cover most braking applications with

variable frequency drives. The M3775RK Braking Resistors are available from 1 – 3000 Hp and can handle

from a 10% up to 100% duty cycle. M3775RK Resistive Solutions are available based on application

requirements. Bonitron offers a wide range of technologies for all your resistive load applications.

• N.C. thermal switch• 10 - 100 % duty cycle ratings available• Durable construction• 2 connections to braking controller• Edgewound solution withstands temperatures up to 800° C

• Remote overload monitoring• Suitable for high vibration and harsh applications• Full line of voltage and duty cycles allows for use with most all braking solutions• Easy retrofit and fits all VFD configurations• Can be used in both AC and DC environments

• Custom design enclosures available• Easy installation• Wide range of solutions to meet your needs• Easy sizing for VFD applications• Maximize uptime

OEM Resistive Load BanksM3775RK

Resistive Solutions

All resistive needs are NOT the same!Bonitron recognizes this and we offer manytypes of resistors to suit your application.

SmoothwoundSmoothwound resistors are most commonly used for light-duty braking of variable frequency drives,small horsepower motor control, space heaters and any low wattage, high resistance load applicationand can be used in AC or DC power circuits. They are suitable for continuous duty applications wherehigh resistance and low current are required. These units are designed to withstand considerableshock, making them suitable for some high vibration applications.

RibbonwoundRibbonwound resistors are similar to Smoothwound resistors in most respects and are also mostcommonly used for motor acceleration and braking, but are also suitable for medium-duty braking ofvariable frequency drives, small horsepower motor control, and space heaters. The ribbed edgesenhance heat dissipation and permit higher wattage ratings for lower ohmic values and can be usedfor AC or DC power applications. These units are designed to withstand considerable shock, makingthem suitable for some high vibration applications.

WirewoundWirewound resistors are designed for low current applications and are suitable for continuous dutyapplications where high resistance and low current are required, including motor control, dynamicbraking, neutral grounding and load testing. They can be used for AC or DC power applications. Thewirewound resistor will withstand considerable shock and vibration, qualifying it for use in mostharsh environments.

EdgewoundEdgewound resistors are most commonly used for VFD braking, motor control, load banks, neutralgrounding applications and can be used for AC or DC power applications. They are suitable forcontinuous duty applications where low resistance and high current capacity are required. The highelement mass allows them to withstand high current, intermittent duty applications. Thischaracteristic, combined with high-temperature ceramic insulation, makes the edgewound ideal forneutral grounding applications, which reach temperatures as high as 800°C.

GridGrid resistors are most commonly used for motor acceleration and braking, but are also suitable forload banks, harmonic filtering and some neutral grounding applications and can be used for AC or DCpower applications. The rigid construction of the elements make them well suited for use in almostany environment, including high vibration areas such as overhead cranes operated in steel mills andmanufacturing plants.

Braking Transistor Field ConnectionsBraking Transistor Field ConnectionsBraking Transistor Field ConnectionsBraking Transistor Field ConnectionsBraking Transistor Field Connections

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BONITRONM3452

orM3575T

InternalInternalInternalInternalInternal

EccentricEccentricEccentricEccentricEccentric

For some applications brakingresistors are required because oftorque or load fluctuations while thespeed remains constant. Someexamples of this are tumblers, punchpresses and pump jacks.

DecelerationDecelerationDecelerationDecelerationDecelerationDuring deceleration, the braking resistor is used to stop orreduce the speed of the motor. The required braking torquereduces with speed, therefore approximately one-half thepower of an overhaulingload cycle is required of thebraking resistor. Mostdrives require brakingresistors only for stopping.

OverhaulingOverhaulingOverhaulingOverhaulingOverhauling

During an overhauling load cycle thebraking resistor keeps the motor speedfrom increasing beyond the speed set bythe drive. The required braking torqueremains constant, therefore approximately twice the power of adeceleration braking cycle is required of the braking resistor.

M3775RKRESISTOR

M3775RKRESISTOR

RATINGS:

ELECTRICAL RATINGS:

DIMENSIONS:

TERMINAL CONFIGURATION:

Bonitron braking resistors are available in (3) duty cycles based on a cycle time of one minute. Braking resistors aredesigned for a 375°C temperature rise when operating at the maximum rated duty cycle. The resistance values aremeasured at 25°C. It is very important to insure that the resistance listed in the chart below is greater than theminimum specified for your drive or braking module. Installing a braking resistor with too low of a resistance valuewill cause permanent damage to your drive or external braking transistor. Please call a member of our engineeringteam if you need assistance at: (615) 244-2825.

These resistor banks are designed to replace or substitute for all of the major manufacturers. These units areelectrically equivalent and are designed to have the same resistance rating. In most cases, our banks will have ahigher current rating, allowing the unit to operate cooler and last longer.

Resistor banks feature universal “mill-frames” and are physically interchangeable with the competitive unit.

In some cases, the location and number of terminals may vary from the unit being replaced.Please specify if your application requires special terminal configurations.

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Check out our website for individual brochures and manuals on most Bonitron products!

- www.bonitron.com -- www.bonitron.com -- www.bonitron.com -- www.bonitron.com -- www.bonitron.com -

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Enclosure:

Braking resistors have through-rod mounted resistor tubesinstalled in ANSI-61 or mill-galvanized gray powder-coated enclosures and arefactory interconnected withstainless steel hardware.

Our resistor enclosures featureconduit knockouts for yourconvenience of easy wiring. Youdecide where the wiring shouldrun and then simply remove theknockout in order to pull thewire into the resistor’senclosure. It’s as easy as that!

521 Fairground Court | Nashville, TN 37211-2008 | U.S.A.Monday - Friday 8:00 - 5:00pm CST | Phone 615-244-2825

Email - info@bonitron.com | Fax 615-244-2833 | www.bonitron.com

To accommodate your application needs please contact Bonitron at (615) 244-2825 with the followinginformation:

Custom Resistive Load BanksCustom Resistive Load BanksCustom Resistive Load BanksCustom Resistive Load BanksCustom Resistive Load Banks

Bonitron offers resistive load banks to cover all braking applications with variablefrequency drives. We offer many different packages ranging from 1 – 3000 hp. Weoffer resistors that can handle 10% duty cycle up to 100%.

Custom Braking Solutions available to fit your applications.

Drive HorsepowerDrive Input VoltageBraking TorqueMaximum Time OnRepeat TimeMinimum ohm rating specified for yourdrive or braking module, or maximumallowable braking current.Enclosure RequirementsCooling Requirements

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Data Requirements:

081019-20080707

More Solutions

M3452 Heavy Duty Braking Transistor Modules• Bonitron M3452 modules are used in applications that have continuous or high duty cycle require-ments. The modules are used with drives that have inadequate or no internal braking transistor. Theywork with any AC drive system with DC bus field terminals. The Bonitron M3452 Braking Transistormodules monitor the drive DC bus levels and control an IGBT power switch which is connected to aresistive load for dissipating the regenerated energy. Standard modules are available rated up to 1200Amps DC and braking Duty Cycles to 100%.

M3345 Line Regen Modules• M3345 modules are used with AC Drives to eliminate overvoltage faults. Bonitron’s M3345 LineRegen is used in systems with extended braking times or frequent regeneration, and makes any VFDmore energy efficient during braking.• The Module quickly pays for itself in mid to high duty applications due to energy being returnedto the utility instead of being wasted as heat• Continuous Braking Duty, 0-120 Amps single unit, 230-460AC line voltages available

M3575T Standard Duty Braking Transistor Modules• Bonitron M3575T modules can be used to increase throughput by decreasing stopping time and aredesigned to be used with all drives with DC bus field terminals. The Bonitron M3575T Braking TransistorModules monitor the drive DC bus levels and control power to a resistive load for dissipating theregenerated energy. Standard modules are available rated up to 600 Amps DC with Braking Duty Cyclesup to 20%.