Product Description

Allen-Bradley 1336-WB035 is a 460 VAC-class dynamic brake chopper module designed for use within the 1336 adjustable frequency drive (AFD) platform by Rockwell Automation. It provides an active DC bus voltage regulation mechanism by enabling controlled dissipation of regenerative motor energy through an external braking resistor.

Functionally, the 1336-WB035 operates as a high-speed IGBT-based switching interface, monitoring the DC link voltage of the drive system and engaging when regenerative energy causes the DC bus to exceed its predefined threshold (typically around 750 VDC). Once activated, the module rapidly switches the braking resistor into the circuit, converting excess electrical energy into thermal energy, thereby preventing DC bus overvoltage faults and drive trip conditions.

This braking chopper is specifically engineered for 380–480 VAC industrial motor control systems, particularly those involving high-inertia loads, frequent deceleration cycles, or regenerative operating conditions. It is widely used in applications such as conveyors, cranes, hoists, centrifuges, and other motion systems where controlled braking torque is required.

Key design characteristics of the 1336-WB035 include a 35 A RMS-rated braking current capability, compatibility with external resistor banks (commonly with minimum resistance around 9 Ω), and integration into legacy Allen-Bradley 1336 series drive architectures. The unit is designed to work as part of a coordinated system with the drive’s rectifier, DC bus capacitors, and thermal protection circuits.

• Rated RMS Braking Current: 35 A
• Peak Regenerative Current Capability: Application-dependent (short-duration overload allowed)
• Overcurrent Protection: External fuse coordination (F1/F2 protection path in drive system)
• Thermal Protection: Internal thermal switch disables operation during overheating events
• Fail-Safe Behavior: Module disables braking output under thermal trip, defaulting to reduced or zero braking torque conditions

 Q1: What is the fundamental electro-power conversion function of the 1336-WB035 in a 1336-series drive system?

A1:
The 1336-WB035 operates as a dynamic braking chopper module, whose primary function is to dissipate regenerated motor energy by switching an external braking resistor across the DC bus. In 1336 adjustable frequency drive systems, the 1336-WB035 prevents DC bus overvoltage conditions during deceleration by enabling controlled energy dissipation through high-speed switching of its IGBT-based chopper circuitry.

Q2: How does the 1336-WB035 implement overvoltage mitigation through its internal semiconductor topology?

A2:
The 1336-WB035 utilizes an Insulated Gate Bipolar Transistor (IGBT) switching element to monitor DC bus voltage and dynamically engage the braking resistor when the bus reaches approximately 750 VDC turn-on threshold. This closed-loop switching architecture ensures precise clamping of regenerative voltage spikes in 460 VAC-class drive environments.

Q3: What are the nominal electrical ratings and operational envelope of the 1336-WB035 module?

A3:
The 1336-WB035 is engineered for medium-voltage industrial drive systems with the following core parameters:

• AC Input Compatibility: 380 / 415 / 460 VAC systems
• Rated DC Bus Activation Level: ~750 VDC
• Continuous Braking Current Capability: 35 A RMS equivalent loading
• Application Class: 460 VAC Adjustable Frequency Drive systems
• Power Dissipation Path: External braking resistor network

These parameters define its suitability for high-inertia load deceleration and frequent regenerative duty cycles.

Q4: In what way does the 1336-WB035 coordinate with external braking resistors in energy dissipation architecture?

A4:
The 1336-WB035 functions as a high-speed switching interface between the DC bus and an external braking resistor. It does not itself dissipate bulk energy; instead, it regulates current flow into a resistive load, enabling controlled thermal conversion of kinetic energy into heat, thereby maintaining DC link stability during regenerative events.

Q5: What distinguishes the 1336-WB035 from conventional braking resistor assemblies in industrial drive systems?

A5:
Unlike passive braking resistors, the 1336-WB035 introduces an active electronic switching layer, enabling:

• Dynamic pulse-width-controlled braking engagement
• Precise DC bus voltage regulation
• Improved thermal management of resistor banks
• Integration into intelligent drive protection schemes

This elevates system braking from passive dissipation to controlled regenerative energy management.