Description
Product Introduction
Alstom MiCOM P142 is a P40 Agile feeder management relay for directional phase overcurrent, earth-fault protection, circuit-breaker control, and automatic reclosing in medium-voltage distribution switchgear.
For replacement procurement, verify the exact P142 order code rather than matching the front label alone. Configurations can differ by I/O option, communications board, hardware suffix, and firmware. Firmware 91I applies to P142 units and supports selectable IEC 61850 Edition 1 or Edition 2; it requires MiCOM S1 Agile 3.2 or later.
Several specifications depend on the full ordering code. Verify the OEM datasheet and relay nameplate before substitution. A relay with the same P142 model designation may still have incompatible communications, I/O, or supply arrangements.
Installation & Configuration Guide
Phase 1—Pre-Installation — estimated 10 minutes
De-energize the protection panel and isolate relevant control circuits. Wait at least 5 minutes for discharge before handling wiring or the relay.
Prepare:
- Calibrated multimeter; we use a Fluke 115 multimeter.
- ESD wrist strap and grounded ESD mat.
- Insulated screwdriver set.
- Wire labels and camera.
- Laptop with the approved MiCOM S1 software version.
- Approved relay settings file and wiring diagram.
Export the existing program or relay configuration where supported. Photograph the relay nameplate, DIP switches, jumpers, wiring, terminal blocks, and rack layout. Record the original firmware, data model, hardware suffix, protocol, and complete order code.
Phase 2—Removal — estimated 5 minutes
Label every wire before disconnection. Release the DIN rail or mounting latch as applicable, then pull the module perpendicular to the backplane. Do not twist the relay against the connector.
Inspect the backplane connector pins for bending, oxidation, contamination, or heat damage. Photograph the removed unit and retain its configuration record as a baseline.
Phase 3—Installation — estimated 10 minutes
Apply ESD protection first. Confirm the replacement part number against the approved procurement record and nameplate.
Replicate the DIP switch and jumper configuration from the photographs. Seat the relay until the latch clicks. Reconnect wiring to approximately 0.5 N·m unless the OEM terminal specification states otherwise.
