Description
ABB REF545KC133AAAA — Feeder Protection Terminal
3. Key Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | REF545KC133AAAA |
| Manufacturer | ABB |
| Product Family | REF 545 |
| Product Type | Feeder Protection Terminal |
| Application | Medium-voltage feeder protection and control |
| Protection Functions | Feeder protection functions, including overcurrent and earth-fault protection |
| Measurement | Electrical current/voltage and power-system measurements |
| Digital I/O | Configuration-dependent |
| Control Functions | Circuit-breaker and switchgear control |
| Event Recording | Supported |
| Fault Recording | Supported on applicable configurations |
| Communication | Configuration-dependent; verify installed communication option |
| HMI | Integrated local operator interface |
| Mounting | Panel/switchgear installation |
| Auxiliary Supply | Verify exact KC133AAAA configuration and nameplate |
| CT/VT Inputs | Verify rated secondary values before replacement |
| Firmware | Verify installed firmware/application version |
| Engineering Software | Verify compatibility with the existing REF545 configuration |
The KC133AAAA designation is important because REF545 units were available in multiple hardware/configuration variants. A tender document, for example, separately identifies REF545-KC133AAAA, REF545-KB133AAAA, and REF545-KM133AAAA, confirming that the suffix should not be ignored when sourcing a replacement.
4. Product Introduction
The ABB REF545KC133AAAA is a REF 545-series feeder protection terminal intended for protection, control, measurement, and monitoring of electrical distribution feeders. It belongs to an older generation of multifunction protection IEDs used in medium-voltage switchgear and distribution installations, where one device can combine protection logic with breaker control, measurement, event handling, and system communication.
REF545KB133AAAA
For maintenance work, the complete ABB REF545KC133AAAA type code should be retained when identifying a replacement. The REF545 family contains multiple configuration variants, and visually similar units cannot automatically be assumed interchangeable. CT/VT ratings, I/O allocation, communication hardware, firmware, and application settings all need to match the existing protection scheme.
5. Application Scenarios & Field Pitfalls (Engineer’s Perspective)
The REF545KC133AAAA is suited to medium-voltage feeder protection, industrial distribution switchgear, substation feeder control, and legacy distribution automation systems. Its practical advantage in an existing installation is the integration of protection and control functions into one feeder terminal, reducing the dependence on separate protection, measurement, and control devices.
Field pitfalls to check:
- Do not substitute by REF545 family alone. The KC133AAAA suffix identifies a specific hardware/configuration variant. Other REF545 variants may have different I/O or communication arrangements.
- Verify CT and VT secondary ratings. Protection settings and input hardware must correspond to the actual instrument-transformer circuits. Never assume a 1 A and 5 A current-input configuration are interchangeable.
- Check the communication architecture. Older REF545 installations can use different communication arrangements. Do not assume that a replacement automatically provides the same protocol or physical interface as the removed unit.
- Preserve the protection configuration. Relay replacement is not simply a hardware swap. Protection settings, logic, breaker-control interlocking, event configuration, and communication parameters should be backed up before removing the existing terminal.
A particularly important procurement point is that several online listings publish conflicting specifications for this exact part number. Claims concerning voltage range, temperature range, Ethernet, IEC 61850, or exact I/O counts should therefore not be accepted without checking the actual ABB documentation for the KC133AAAA configuration.
6. Related Products
- ABB REF541KC133AAAA — REF 541 feeder terminal; same general feeder-protection family but different device configuration and I/O capacity.
- ABB REF543KC133AAAA — REF 543 feeder terminal; another member of the REF 541/543/545 generation with different hardware capabilities.
- ABB REF545KB133AAAA — Closely related REF545 configuration; the suffix difference is significant for replacement compatibility.
- ABB REF545KM133AAAA — Another REF545 configuration variant; verify hardware and I/O allocation before substitution.
- ABB REF542PLUS — Integrated protection and control device for distribution applications, but based on a different hardware generation and configuration approach.
- ABB REF615 — Later-generation feeder protection platform; potentially relevant for migration projects, but it should not be treated as a drop-in replacement without engineering review.
- ABB RED670 — Line differential protection platform serving a different protection application; relevant to transmission/substation protection rather than direct REF545 feeder replacement.
Procurement Note
For a REF545KC133AAAA replacement, obtain the complete nameplate information and, if possible, the existing relay configuration before purchasing. The exact suffix, current-transformer rating, auxiliary supply, I/O arrangement, communication interface, firmware, and protection application should all be checked. For a protection-critical feeder, functional testing and secondary-injection verification should be completed before returning the relay to service.
