Allen-Bradley 1336-RFB-30-A-4 RFI Filter for 1336 PLUS

Allen-Bradley 1336-RFB-30-A-4 RFI Filter for 1336 PLUS

The Allen-Bradley 1336-RFB-30-A-4 is a dedicated RFI (Radio Frequency Interference) filter module engineered for seamless integration within the 1336 PLUS AC drive platform. In modern industrial automation environments, electromagnetic compatibility is not an afterthought — it is a foundational requirement of any well-designed control system architecture. This filter module is purpose-built to suppress conducted EMI emissions at the drive input, ensuring that the broader control network — spanning the control layer, I/O layer, communication layer, power layer, HMI layer, and actuator layer — operates with maximum signal integrity and regulatory compliance.

When deployed within a 1336 PLUS drive system, the 1336-RFB-30-A-4 sits at the interface between the incoming AC power supply and the drive’s rectifier stage. Its role is to attenuate high-frequency noise generated during PWM switching, preventing that noise from propagating back into the plant power distribution network. This directly protects upstream devices such as PLCs, I/O modules, communication gateways, and HMI terminals from interference-induced faults — a critical consideration in process-critical environments where signal reliability determines uptime.

From a system architecture perspective, the 1336-RFB-30-A-4 contributes to the overall coherence of the drive cabinet design. It is rated for 30A input current and is compatible with the 1336 PLUS and 1336 PLUS II drive families, making it a consistent component choice across multi-drive installations. Engineers specifying this filter can standardize their cabinet layouts, simplify maintenance procedures, and reduce the risk of EMC non-compliance during commissioning audits.

Product Specification Table

System Compatibility Notes

The 1336-RFB-30-A-4 does not operate in isolation — it is one component within a coordinated drive and control architecture. In a typical 1336 PLUS installation, the filter is mounted ahead of the drive’s AC input terminals and works in conjunction with the drive’s internal DC bus capacitors and gate driver circuitry to deliver a clean power environment throughout the system.

At the control layer, the Allen-Bradley 1336 PLUS drive itself — available in variants such as the 1336F-BRF30-AN-EN and 1336S-BRF30-AN-EN — receives speed and torque commands from a supervisory PLC, typically a ControlLogix 1756-L71 or CompactLogix 1769-L33ER controller. These controllers communicate with the drive via 1336-GM6 (DeviceNet) or 1336-GM1 (DH+) communication adapter modules, which plug directly into the drive’s communication bay. The RFI filter ensures that switching transients from the drive’s IGBT output stage do not corrupt the low-voltage communication signals traveling on these networks.

At the I/O layer, discrete and analog signals from field devices — sensors, encoders, limit switches — are wired into 1756-IB16 digital input modules or 1756-IF8 analog input modules housed in a ControlLogix chassis. These modules are sensitive to common-mode noise, and the 1336-RFB-30-A-4 plays a direct role in reducing the noise floor across the entire cabinet, improving the accuracy of analog signal acquisition.

At the power layer, the filter is typically installed downstream of a 1321-3R30-C line reactor or upstream of a 1336-BRB-30 dynamic braking module, forming a complete power conditioning chain. This arrangement is especially important in regenerative braking applications or multi-drive systems sharing a common bus, where harmonic and EMI interactions between drives can cause nuisance tripping or communication faults.

At the HMI layer, operator interface terminals such as the PanelView Plus 6 (2711P-T10C4D8) communicate with the ControlLogix controller over EtherNet/IP. A clean electrical environment — maintained in part by the 1336-RFB-30-A-4 — ensures that HMI screen updates, alarm acknowledgments, and parameter write commands are transmitted without packet loss or latency spikes.

At the network layer, managed switches such as the Stratix 5700 or unmanaged switches in the 1783-US series distribute EtherNet/IP traffic across the plant floor. EMI-induced noise on the power distribution network can couple into Ethernet cabling through ground loops; the RFI filter reduces this risk by attenuating the source of the interference at the drive input.

Industrial Application Notes

The 1336-RFB-30-A-4 finds application across a wide range of industrial sectors where the 1336 PLUS drive platform is deployed:

Manufacturing & Assembly Lines: In automotive body shop conveyors and transfer lines, multiple 1336 PLUS drives control conveyor motors simultaneously. RFI filters on each drive prevent cross-interference between adjacent drive cabinets, ensuring synchronized motion control and reducing false encoder faults.

Power Generation & Utilities: In pump and fan applications at power stations, the 1336-RFB-30-A-4 supports compliance with utility-grade EMC requirements. Drives controlling boiler feed pumps or cooling tower fans must meet strict conducted emission limits to avoid interfering with protection relay systems operating on the same electrical bus.

Petrochemical & Refining: In hazardous area installations where drives are mounted in purged and pressurized enclosures (Zone 2 / Division 2), the RFI filter is installed in the clean air section of the enclosure. Its compact form factor and panel-mount design make it compatible with space-constrained cabinet layouts common in offshore and refinery environments.

Water & Wastewater Treatment: Municipal water treatment facilities rely on 1336 PLUS drives for variable-speed pump control. The 1336-RFB-30-A-4 ensures that SCADA communication signals — typically transmitted over Modbus RTU or EtherNet/IP — are not disrupted by drive switching noise, maintaining continuous process monitoring and control.

Mining & Minerals Processing: In conveyor and crusher drive applications, high-power drives generate significant EMI. The 1336-RFB-30-A-4, combined with a line reactor, provides a two-stage input filter that protects both the drive and the upstream power distribution equipment from harmonic and EMI stress.

Packaging & Material Handling: High-speed packaging lines require precise speed synchronization between multiple drives. RFI filters on each drive reduce the risk of communication-induced speed deviations, supporting the tight timing tolerances required for label application, filling, and sealing operations.

Product Compatibility FAQ

Q1: Is the 1336-RFB-30-A-4 compatible with both the 1336 PLUS and 1336 PLUS II drive families?
Yes. The 1336-RFB-30-A-4 is designed for use with both the 1336 PLUS and 1336 PLUS II AC drive series. It is rated for 30A input current at 480V AC (3-phase) and mounts directly in line with the drive’s AC input terminals. When replacing or upgrading drives from the original 1336 PLUS to the 1336 PLUS II platform, the same filter can be retained, simplifying the upgrade process and reducing spare parts inventory requirements.

Q2: How does this RFI filter affect the overall EMC compliance of a multi-drive control cabinet?
In a multi-drive cabinet, each drive must be individually filtered to prevent its conducted emissions from coupling into the shared power bus and affecting adjacent drives, PLCs, or communication networks. The 1336-RFB-30-A-4 provides per-drive EMI suppression at the input stage, which is the most effective point of intervention. When combined with proper cable segregation, shielded motor cables, and a low-impedance cabinet ground bus, this filter supports compliance with IEC 61800-3 Category C2 requirements for industrial environments. Engineers should verify the total filter leakage current against the system’s ground fault protection settings during commissioning.

Q3: What does the warranty terms confirmed during quotation cover, and how does it support long-term maintenance planning?
The warranty terms confirmed during quotation covers manufacturing defects and functional failures under normal operating conditions from the date of shipment. For maintenance engineers managing aging 1336 PLUS installations, this warranty provides a defined support window that can be aligned with annual maintenance cycles and spare parts budgeting. In practice, RFI filters have long service lives when operated within their rated current and temperature specifications; the warranty period reflects our confidence in the product’s reliability. For sites with critical uptime requirements, we recommend holding one spare 1336-RFB-30-A-4 per drive cabinet to enable rapid replacement without waiting for procurement lead times.