Application Scenarios

In a mining hoist application using an ABB ACS 600​ drive, when the loaded cage descends, the motor acts as a generator, pumping energy back into the drive’s DC bus. The SNAT617 CHC​ module detects this rising DC voltage and triggers the external braking IGBT/Thyristor to “dump” the excess energy into a large resistor bank. This prevents the DC bus voltage from spiking to dangerous levels that could damage capacitors or power modules, ensuring a controlled and safe stop.

 

Parameter

Main Parameters	Value/Description
Product Model​	SNAT617 CHC​ (SNAT617CHC)
ABB Part Number​	61037136D​ (Key identifier for ordering)
Manufacturer​	ABB
Product Category​	Drive Control Board (Brake Chopper Controller)
Primary Function​	DC Bus Overvoltage Protection, Brake Chopper Control
Compatible Drives​	ABB ACS 600, ACS 617, ACS 677 series
Control Method​	IGBT/Thyristor Gate Drive, PWM Control
Power Supply​	+24V DC (typically derived from drive internal PSU)
Communication​	Internal drive bus (to RDCU/RDCO main board)
Status Indication​	LED indicators for power, fault, and brake activity
Operating Temp.​	-20°C to +70°C (typical industrial range)

 

 

Technical Principles and Innovative Values

• Innovation Point 1: Dynamic Voltage Clamping for System Protection:​ The core innovation of the SNAT617 CHC​ is its real-time monitoring of the DC link voltage. It uses a precision voltage-sensing circuit to compare the bus voltage against a safe threshold. When regenerative braking causes the voltage to exceed the limit, the board generates a high-frequency PWM signal to switch the external brake IGBT, effectively “clamping” the voltage and preventing catastrophic failure of the DC bus capacitors and power semiconductors.
• Innovation Point 2: Adaptive Braking Energy Management:​ Unlike simple on/off controllers, this module employs an adaptive control algorithm. It modulates the duty cycle of the brake chopper based on the rateof voltage rise and the load’s inertia. This provides smooth, jerk-free deceleration in high-inertia applications like centrifuges or large fans, avoiding mechanical stress on the drivetrain while efficiently dissipating energy.
• Innovation Point 3: Integrated Fault Diagnostics and Isolation:​ The board incorporates comprehensive self-diagnostic features. It monitors the health of the external braking resistor (for open or short circuits) and the chopper IGBT itself. In the event of a fault (e.g., brake resistor burnout), it immediately signals the main drive controller (RDCU) to trip the drive safely, preventing damage. The control circuits are also galvanically isolated to protect the low-voltage logic from high-voltage transients on the power side.

 

Application Cases and Industry Value

Case 1: Steel Mill Crane Retrofit, Tianjin, China.​ A steel plant’s overhead crane, driven by an ACS 617​ drive, was experiencing frequent “DC Link Overvoltage” faults during rapid lowering of heavy slabs. The issue was traced to an aging SNAT617 CHC​ board that was no longer responding quickly enough to voltage spikes. Replacing the board with a refurbished 61037136D​ unit restored the dynamic braking performance, eliminating the faults and reducing mechanical shock on the crane’s gearbox, thereby extending its service life.Case 2: Wastewater Treatment Plant Fan Drive, Germany.​ A large blower in aeration basins, controlled by an ACS 600​ drive, required frequent deceleration. The existing braking system was inefficient. An upgrade included optimizing the braking resistor value and ensuring the SNAT617 CHC​ module was correctly configured for the new load profile. This resulted in a 15% reduction in stopping time and improved the overall energy management of the plant’s electrical system.