MBC2K 24-100VDC - 2kW Brake Resistor Chopper Controller

These are specific products for niche applications, which include some breakthrough achievements. MBC2K is the first CPU controlled brake chopper controller for DC motors that can control brake resistors up to 2kW (several units can be paralleled for more power) and in any range from 24V to 100VDC. Although this product was developed specifically for DC motors. This product works well in any situation where energy needs to be released/dissipated from the DC bus to prevent over voltage errors. We use it at DamenCNC mainly for stepper motors systems.

When CNC or other motion controlled machines have very high accelerations and decelerations. On deceleration a big rise in DC bus voltage happens, because the mechanical energy is turned into electrical energy under braking. If nothing is done with this energy, it means the DC bus voltage will increase. In some cases the DC bus voltage will go over the value which is allowed by the stepper driver, or by the power supply. This can cause component failures due to over voltage. Or it can cause stepper drivers to go into an over voltage error. In any case it means the machines will be down. A brake chopper driver is the solution. All you need to do is connect the + and - of your power supply DC connection to the DC-IN of this MBC2K device. Then you can set the DC bus voltage above which it needs to activate the brake resistor to dissipate the power into heat.

For example, let's say we have a 72VDC power supply. It can cope with maximum 100VDC before it goes into error. The stepper drivers CS-D1008E that are coupled will go into error above 110VDC. So if we set the brake that it starts to dissipate energy above 94VDC (setting 17). Then under heavy braking if the voltage goes over 94VDC, the brake chopper is activated, and voltage is dropped to the VTL level which is 3-6VDC lower. Depending on how you have set the hysteresis. We recommend 6VDC above 50VDC bus voltage. Meaning voltage goes down to a safe 88VDC.

This MBC2K device developed by TDK Nexts is very advanced. It has an ALARM output which you can connect to the CNC or PLC. It will indicate when the unit has a malfunction. But also Undervoltage and Overvoltage of the DC bus. Over temperature if a temperature sensor is connected. It will even detect if the brake resistor is not connected.

Technical Specs:

• Input phase: DC only
• Rated Input Voltage Range: 24 - 110VDC
• Output overvoltage protection: >=100VDC
• Continuous current: 50 A
• Overload Limit in constant current mode: 80 A (for max 1 second)
• Cooling by free air convection
• Suitable for mounting on DIN Rails TS-35/7.5 of TS-35/15
• UL508 (industrial control equipment) approved
• EN61000-6-2(EN50082-2) Industrial immunity level
• Protections: Overload, Thermal Protection, Input undervoltage lockout, Output Overvoltage
• User interface: 2x 7 segments LED displays, SET/RESET  and  MENU - 2 programming keys
• Status Signals: ALARM (Red LED),  ALARM potential free contact NO (24VDC 1A max)

Component features:

• 24-100VDC / 2kW Brake Resistor Chopper Controller for DC motors and Steppermotors
• 55mm width
• Rating: 24-100VDC / 2kW
• CPU controlled, 2 digit user interface
• User settable brake voltage threshold
• Usable with ANY DC power supply
• Protection against resistor fault
• Several units can be paralleled for increased power (max 4 units for 8kW)
• Nextys part name:MBC2K