Description

ABB SPAU140C Relay | Panel Mount Synchro Protection Device with SPA Bus Communication

Product Core Brief

Model: SPAU140C
Brand: ABB
Series: SPA series numerical protection relays
Core Function: Validate synchronism conditions to enable safe circuit breaker closing
Type: Synchro-Check Relay
Key Specs: Dual independent operation stages, synchro-check & voltage-check modes, SPA optical serial bus
Condition: New Surplus, non-refurbished

⚠️ Discontinued by ABB since 2012, factory serial production stopped, limited spot inventory available

Product Introduction

Out-of-phase closing can inflict permanent damage on generators and transformers inside power substations. The ABB SPAU140C acts as a critical interlock element for medium voltage switchgear, monitoring voltage, phase angle and frequency difference across breakers.

Unlike single-channel synchronism devices, this unit contains two identical processing stages. It supports duplex switchgear layouts and handles two separate circuit breakers within one device. Continuous self-monitoring tracks internal hardware status and triggers IRF fault alarms once anomalies are detected. The relay works well for bus tie switching, generator grid connection and network restoration tasks.

Key Technical Specifications

Parameter	Specification
Part Number	SPAU140C
Device Type	Microprocessor-based synchro-check relay
Rated Measuring Voltage	100 V / 110 V (VT secondary)
Frequency Range	45 … 65 Hz (supports 50 Hz / 60 Hz)
Auxiliary Supply Range	80 … 265 V AC / 18 … 265 V DC
Operating Stages	2 independent identical stages
Working Modes	Synchro-check, voltage-check; continuous / command operation
Communication Interface	SPA serial bus (electrical or fiber optic)
Output Contact Rating	250 V AC/DC, continuous 5 A
Mounting Form	Panel flush mounting, 4U standard case
Self-Supervision	Built-in hardware & software diagnostic with IRF alarm output
Operating Temperature	-5 °C ~ +55 °C
Origin	Finland

ABB SPAU140C Relay

Installation & Configuration Guide

Pre-Installation (Estimated: 12 min)

⚠️ Safety Reminders:

Schedule maintenance shutdown and implement lockout-tagout procedures
Confirm all connected voltage transformers are isolated
Discharge residual voltage on secondary wiring of VT circuits
Prepare documentation for original setting parameters

Tools required:

ESD wrist strap and anti-static mat
PH1 cross screwdriver
Digital multimeter
Camera for recording wiring layout and front panel settings
Printed wiring diagram of the switchgear control circuit

Backup tasks:

Record all configured threshold values: ΔU, Δf, phase angle limit
Capture clear photos of all terminal wiring
Save historical fault records stored inside the relay memory

Old Unit Removal (Estimated: 15 min)

Label every VT signal wire, auxiliary power cable and relay output contact wire
Disconnect low-current measurement circuits first; avoid open-circuit risk on VT secondary loops
Remove front panel cover, then unscrew mounting fasteners around the relay housing
Pull the relay slowly outward from the cutout panel
Inspect terminal blocks for oxidation, overheating marks or loose screw traces

⚠️ Do not short VT secondary terminals randomly during disassembly.

New Module Installation (Estimated: 18 min)

Apply ESD protection before unpacking the relay
Match model designation and auxiliary voltage version with the removed unit
Fit the relay into the panel cutout and secure mounting screws evenly
Reconnect wiring strictly following photographed reference layout
Access setting menu and restore all synchronism parameters from backup records
Complete pre-power checklist:

☑ All VT circuits wired without reversed polarity

☑ Auxiliary power terminals correctly connected

☑ No exposed loose conductors inside cabinet

☑ Communication cable matched for electrical or optical SPA bus

Power-On & Function Test (Estimated: 35 min)

Pre-power inspection:

Measure auxiliary supply voltage to stay within 80–265 V range
Verify no short circuits exist on voltage measurement inputs

Test steps:

Switch on auxiliary power only; keep all primary high voltage circuits isolated
Check front panel display, confirm no permanent IRF fault codes
Navigate menu to verify all restored setting values
Inject simulated voltage signals via secondary injection test set
Test both synchro-check and voltage-check logic for Stage 1 and Stage 2
Confirm output contacts actuate only when all synchronism thresholds are satisfied
Run continuous monitoring test for minimum 30 minutes, record operation status

Troubleshooting tips:

IRF fault code displayed: Internal hardware defect, replacement required
No closing permission output: Check phase sequence, VT polarity or threshold limits
SPA bus communication failure: Inspect fiber cable or terminal termination resistance

Frequently Asked Questions (FAQ)

Q: Can SPAU140C be directly replaced with newer ABB synchro protection relays?

A: Direct plug-and-play swap is not available. Newer generation devices use different terminal definitions and logic architectures. Modifications to control wiring and logic interlocks will be required.

Q: Is hot swapping supported while auxiliary power remains energized?

A: Hot removal is not recommended. Interruption of VT secondary wiring during live maintenance creates dangerous high voltage risks on open terminals. Full auxiliary power shutdown is mandatory.

Q: What difference exists between continuous mode and command mode?

A: Continuous mode delivers permanent closing permission once conditions are met, often used for automatic bus transfer schemes. Command mode only triggers output after receiving external closing request signals, widely adopted for manual breaker control panels.

Q: Can one SPAU140C handle synchronism for two separate bus tie breakers?

A: Yes. The dual independent stages allow monitoring two breakers simultaneously. Each stage can be configured separately for synchro or voltage check logic. We have implemented this layout on multiple duplex substation projects.

Q: Will stored setting parameters be lost after power interruption?

A: Setting values are saved in non-volatile memory. Short power cuts do not erase configurations. Extended storage without power does not affect saved parameters.

Q: What risks appear if VT polarity gets reversed during installation?

A: Phase angle measurement generates wrong readings. The relay will continuously reject closing commands even under actual synchronized conditions. Verify phase sequence before commissioning.

Q: Does the warranty cover damage caused by wrong VT connection or overvoltage on measurement inputs?

A: Warranty excludes failures induced by incorrect wiring, transient overvoltage, lightning surges or improper secondary injection testing. All units complete bench testing before dispatch, test records can be provided upon request.