GE Multilin 889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1 Generator Protection Relay

Description

GE Multilin 889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1 Generator Protection Relay

Product Introduction

GE Multilin 889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1 is a highly configured Multilin 889 generator protection and management relay intended for generator electrical protection, monitoring, control, and plant integration. The 889 platform is a microprocessor-based generator protection system rather than a simple overcurrent relay. Its ordering structure defines the measurement inputs, power supply, low- and high-voltage I/O, protection functions, control logic, monitoring package, and communications architecture. The configuration supplied here uses P5 phase-current banks, B5 ground-current inputs, a 24–48 VDC power supply, and multiple RTD and relay I/O sections.

The GE Multilin 889 configuration uses P5 on both current-input banks, providing 5 A three-phase current inputs with associated voltage inputs. The B5 ground-current configuration combines 5 A ground inputs with a sensitive 50:0.025 ground input. Its L power-supply code specifies 24–48 VDC. Slots B and C each provide six RTD inputs, while slots F and H provide Form A/Form C relay outputs and seven digital inputs. Slot G provides seven DC milliamp outputs, four DC milliamp inputs, and one RTD input. This combination gives the relay substantial generator monitoring and control I/O without relying entirely on external I/O hardware.

GE Multilin 889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1 also carries advanced current and voltage protection packages. The A current-protection option adds elements including 67P, 67_2, 87GD/REF/RGF, and 87O, while P voltage protection adds functions including 55, 59P, 59N, 59_2, 64TN, 78, and 81R. The C monitoring option adds breaker health reporting and thermal overload functionality. The SE communications option provides front USB, rear RS485, and Ethernet capabilities, while C in the advanced communications connector position specifies RJ45 copper 10/100 Mbps.

Technical Specifications

Configuration details are derived from the Multilin 889 ordering structure and closely matching documented configurations.

889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1

Main Features and Engineering Considerations

Advanced Generator Protection

The 889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1 configuration includes the advanced current-protection package. The A option adds 67P and 67_2 directional overcurrent functions, 87GD ground differential/restricted ground fault protection, and 87O overcurrent-related protection to the standard current-protection package.

The voltage-protection package is also advanced. It includes functions associated with power factor, voltage, negative-sequence voltage, stator ground fault, phase-angle, and frequency-rate protection. The exact protection elements that are enabled in the final settings file still depend on application configuration.

Dual 5 A Measurement Banks

P5/P5 is important when replacing an installed relay. Both J and K banks are configured for 5 A three-phase current inputs with voltage inputs. The relay should therefore be matched against the existing CT secondary rating and VT wiring rather than treated as a generic 1 A/5 A selectable relay.

Sensitive Ground-Fault Measurement

The B5 option combines conventional 5 A ground-current inputs with a sensitive 50:0.025 ground input. This is significant for generator ground-fault schemes where the protection engineer needs a measurement path with a substantially different current ratio from the conventional phase CT circuits.

RTD and Control I/O

The two S-coded low-voltage I/O slots provide six RTDs each. Slots F and H each provide relay and digital-input capacity, while G provides analog DC inputs and outputs plus an RTD. This gives the relay direct access to generator temperature, breaker status, trip circuits, control commands, and analog process values.

Communications Architecture

The SE communications package includes a front USB interface, rear RS485, and Ethernet. Documented protocols include Modbus RTU, DNP3.0, IEC 60870-5-103, and Modbus TCP/DNP over Ethernet. The C advanced-communications connector specifies an additional RJ45 copper 10/100 Mbps arrangement.

This is a configuration where the exact communication hardware matters. Do not substitute a relay having the same basic 889 model but a different communications code without checking the plant SCADA architecture.

Application Scenarios

• Diesel generator protection
• Gas engine generator protection
• Steam turbine generator protection
• Industrial generator sets
• Emergency generator systems
• Utility-connected synchronous generators
• Generator breaker protection and control
• Generator ground-fault protection
• Generator differential / restricted ground-fault schemes
• Generator RTD monitoring
• Generator thermal monitoring
• SCADA-connected generator protection panels
• GE Multilin 489 replacement projects

Engineer’s Guide: Field Pitfalls

1. Verify the complete order code, not just “Multilin 889.”
The 889 platform has substantial configuration variation. Current-input banks, power supply, I/O, protection functions, communications, and faceplate options can all change.

2. Confirm the CT secondary rating.
This specific configuration uses 5 A phase-current inputs. A 1 A CT system requires a different input configuration.

3. Verify the ground-current circuit carefully.
B5 combines 5 A ground measurement with a 50:0.025 sensitive ground input. CT wiring and grounding protection architecture must match the original engineering design.

4. Check the DC supply before energizing.
The L configuration is 24–48 VDC. Do not apply the 110–250 VDC / 110–230 VAC supply associated with the H configuration.

5. Do not assume every protection function is enabled.
The order code establishes available protection functionality; actual operation depends on the loaded settings file and enabled elements.

6. Protect the settings file during replacement.
GE’s retrofit documentation specifically requires saving and converting the existing settings file when migrating from a Multilin 489 to an 889. The converted settings must be reviewed before loading into the replacement relay.

7. Match communications hardware.
The SE communications package and C advanced connector produce a specific communications architecture. Verify the SCADA protocol, Ethernet topology, RS485 wiring, and addressing before commissioning.

8. Treat 4-1 as an exact suffix.
I found closely related 889 configurations using suffixes such as 4-2 and 4-1-043X, but I did not find sufficiently authoritative documentation that establishes the exact meaning of your standalone 4-1. Do not silently replace it with another suffix during procurement.

Frequently Asked Questions

What is the 889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1?

It is a specific configuration of the GE Multilin 889 generator protection and management relay.

What is the power supply?

The L power-supply code specifies 24–48 VDC.

Are the phase CT inputs 1 A or 5 A?

They are 5 A. Both P5 phase-current banks are configured for 5 A three-phase current inputs.

What ground-current inputs are included?

The B5 configuration provides 5 A ground-current inputs plus a 50:0.025 sensitive ground input.

Does this relay support generator differential protection?

The advanced current-protection option A includes 87GD, associated with generator ground differential/restricted ground-fault protection. Whether and how the element is applied depends on the generator protection scheme and settings.

How many RTD inputs are configured?

Slots B and C each provide six RTD inputs, giving 12 RTD channels across those two slots. Slot G also includes one RTD input.

What communications are included?

The SE package includes front USB, rear RS485, and Ethernet. Documented protocols include Modbus RTU, DNP3.0, IEC 60870-5-103, Modbus TCP, and DNP. The C advanced connector is an RJ45 copper 10/100 Mbps interface.

Does the relay have wireless communication?

No. The N wireless option specifies no wireless communication.

What does the C monitoring option provide?

The C monitoring package is documented as the standard monitoring package plus breaker health reporting and 49TOL thermal overload.

Procurement Note

For this exact relay, the complete ordering code should be preserved:

889-E-P5-P5-B5-L-S-S-A-L-A-M-A-P-F-C-SE-N-N-B-4-1

The most important replacement checks are 5 A CT inputs, B5 ground-current configuration, 24–48 VDC supply, 12 RTDs in slots B/C, F/G/H I/O configuration, advanced current protection, advanced voltage protection, C monitoring, SE communications, and RJ45 copper advanced communications.

If this is replacing a Multilin 489, do not treat the hardware swap as the complete job. GE’s retrofit documentation requires preservation and conversion of the 489 settings file, followed by review of the conversion results before loading the settings into the 889. GE also documents that a settings-file revision mismatch with relay firmware can prevent the file from being loaded.

For procurement records, I would list the complete string exactly as supplied and require a nameplate photograph or OEM configuration confirmation. The final 4-1 suffix remains a configuration identifier that should not be guessed or normalized to a nearby 889 variant.