ABB SPAJ 135 C-AA Maintenance-Proven Spare Part for Factory Uptime

Overview

ABB SPAJ 135 C-AA Maintenance-Proven Spare Part for Factory Uptime

The ABB SPAJ 135 C-AA is a combined overcurrent and earth-fault protection relay from ABB’s proven SPAJ Series, widely deployed in medium-voltage switchgear, motor feeders, transformer protection panels, and industrial distribution networks. Designed for demanding continuous-operation environments, this relay delivers reliable three-phase overcurrent protection alongside sensitive earth-fault detection — making it a critical component in any maintenance engineer’s spare parts inventory for aging or legacy ABB protection systems.

At KNMKS, every SPAJ 135 C-AA unit is sourced as an original ABB spare, subjected to pre-shipment functional testing, and dispatched with a support terms confirmed by quotation. Multi-region stock availability ensures global delivery details confirmed by RFQ for both emergency replacements and scheduled outage windows, minimizing unplanned downtime in power distribution, process automation, and heavy industrial facilities.

Spare Maintenance Table

Maintenance Planning for Continuous Operation

When scheduling a replacement of the SPAJ 135 C-AA during a planned outage or emergency callout, maintenance engineers should treat the relay as part of a broader protection circuit review. The SPA-bus communication interface connects the relay to ABB’s SPACOM or similar substation automation systems — verify that the SPA-bus cable and optical fiber link (if used) are intact and that the master station polling address matches the replacement unit’s configured address before energizing.

Current transformer (CT) secondary wiring should be inspected for insulation integrity and correct polarity before reconnecting to the relay’s current input terminals. If the panel uses a 5 A CT secondary and the replacement relay is configured for 1 A input, a mismatch will cause incorrect tripping thresholds — always confirm the CT ratio against the relay’s rated current input. Alongside the relay, inspect the auxiliary power supply fuse (typically a 2 A or 4 A glass fuse on the 110 V or 220 V DC bus) and replace it as a precaution if the original relay failed due to an overvoltage event.

For panels housing multiple SPAJ-series relays — such as the SPAJ 140 C (motor protection) or SPAJ 131 C (overcurrent only) — a cabinet-level inspection is recommended: check terminal block tightness on the DIN rail-mounted terminal strips, verify that the trip relay output wiring to the circuit breaker shunt trip coil is secure, and confirm that any interposing relay or output relay module in the trip circuit is functional. If the panel includes an ABB REF 541 or REF 542plus feeder terminal, ensure that the SPAJ relay’s trip signal integration with the feeder terminal’s binary input is correctly mapped after replacement.

Procurement engineers sourcing the SPAJ 135 C-AA for buffer stock should also consider holding one unit each of the SPAJ 140 C and SPAJ 131 C to cover the full SPAJ family deployed across a typical substation bay. Additionally, stocking a spare SPA-bus communication module and a set of auxiliary relay output contacts reduces the risk of extended downtime if secondary failures occur during the same outage window. For panels with integrated ABB SPCJ 4D29 or similar plug-in relay modules, verify that the relay socket and backplane connector pins are clean and undamaged before inserting the replacement unit.

Site Replacement Workflow

Step 1 — Isolation & Permit: Obtain a Permit to Work (PTW) and isolate the feeder circuit. Confirm that the circuit breaker is open and locked out. Verify zero voltage on the CT secondary using a clamp meter before disconnecting wiring.

Step 2 — Documentation: Photograph the existing relay’s front panel settings (overcurrent pickup, time multiplier, earth-fault pickup) and record the SPA-bus address from the relay’s configuration menu or the panel’s protection setting schedule. These values must be replicated on the replacement unit.

Step 3 — Removal: Disconnect the auxiliary supply, CT secondary leads, trip output wiring, and SPA-bus cable in sequence. Withdraw the relay from its draw-out case or unscrew the flush-mount panel cutout fixings. Label all disconnected wires before removal.

Step 4 — Installation: Insert the SPAJ 135 C-AA replacement unit. Reconnect wiring in reverse order. Torque terminal screws to the manufacturer’s specification (typically 0.5–0.8 Nm for signal terminals). Restore the SPA-bus address and protection settings using the relay’s front-panel keypad or ABB’s CAP 505 relay setting tool.

Step 5 — Commissioning Test: Apply auxiliary supply and verify that the relay powers up without fault LEDs. Inject a secondary test current using a relay test set (e.g., Omicron CMC series) to confirm overcurrent and earth-fault pickup values match the protection setting schedule. Verify trip output contact operation and SPA-bus communication response before returning the feeder to service.

Step 6 — Return to Service: Close the circuit breaker under supervision, confirm normal load current readings on the relay’s ammeter display, and update the maintenance log with the replacement date, unit serial number, and test results.

Spare Parts Support FAQ

Q1: Is the SPAJ 135 C-AA a direct drop-in replacement for an existing SPAJ 135 C unit already installed in my panel?
The SPAJ 135 C-AA shares the same SPAJ Series housing and terminal layout as other SPAJ 135 C variants. However, the suffix “AA” denotes a specific auxiliary voltage and output contact configuration. Always verify the auxiliary voltage rating and CT input rating against your panel’s nameplate and protection setting schedule before installation to confirm full compatibility.

Q2: How do I verify that the replacement relay has been tested before shipment?
Every SPAJ 135 C-AA unit dispatched by KNMKS undergoes pre-shipment functional testing covering auxiliary supply energization, overcurrent and earth-fault pickup verification, and output contact continuity checks. A test record is available upon request. The unit ships with a support terms confirmed by quotation covering manufacturing defects and functional failures under normal operating conditions.

Q3: Can KNMKS support long-term supply of the SPAJ 135 C-AA for multi-site maintenance programs?
Yes. KNMKS maintains multi-region buffer stock of SPAJ Series relays to support scheduled outage programs, annual maintenance contracts, and emergency callout requirements. Long-term supply agreements with fixed pricing and priority dispatch are available for facilities managing multiple ABB protection panels. Contact admin@knmks.com to discuss volume and lead-time commitments.

Q4: What is the recommended inventory strategy for SPAJ Series relays in a substation with 10–20 feeders?
For substations with 10–20 SPAJ-protected feeders, a minimum buffer of 2–3 SPAJ 135 C-AA units is recommended, supplemented by one unit each of any other SPAJ variants (e.g., SPAJ 140 C, SPAJ 131 C) deployed on site. This buffer supports same-day replacement during unplanned outages without waiting for procurement lead times, which can extend to 4–12 weeks for legacy ABB protection relays sourced through standard channels.

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Product Identification

Brand / Ecosystem

ABB
ABB

Model / Series

SPAJ 135 C-AA

Product Family

Relays & Interface

Availability Status

Available on request after model and quantity confirmation

Inquiry Type

B2B RFQ, replacement inquiry and project spare-part request

Pre-Quote Check

Exact SKU, brand, series, quantity, nameplate photos and destination country are checked before quotation

Specification & Inquiry Focus

Interface range

Relays, isolation and signal modules

Common needs

Coil voltage and contact rating

Project support

Panel wiring and signal protection

Inquiry Support

• Relay base and module matching
• Signal isolation and protection options
• Panel accessory inquiry support

What to Send Us

• Brand and exact model number: ABB SPAJ 135 C-AA
• Quantity and required delivery time
• Application, replacement requirement or nameplate photo
• Destination country and shipping preference