GE 339-E-P5-G5-H-E-S-N-N-SN-D-N Multilin 339 Motor Protection Relay

Description

Product Introduction

The GE 339-E-P5-G5-H-E-S-N-N-SN-D-N is a member of the Multilin 339 motor protection family designed for low- and medium-voltage motor applications. It combines protection, motor control, diagnostics, event recording, and communications in a single microprocessor-based relay suitable for pumps, compressors, fans, conveyors, and other critical rotating equipment.

This configuration is equipped with 5 A phase and ground current inputs, a high-range AC/DC power supply, standard digital I/O, and RS485 Modbus RTU communications. Unlike older thermal overload relays, the Multilin 339 continuously calculates motor thermal capacity, records operating events, and provides detailed diagnostics that simplify troubleshooting after an unexpected trip.

Key Technical Specifications

Application Scenarios & The “Trench” Experience

I’ve seen this more than once.

A refinery schedules a routine shutdown. During startup, one medium-voltage compressor refuses to run because the existing protection relay fails its self-diagnostics. Production cannot restart until the relay is replaced, tested, and synchronized with the plant control system. A relay that normally receives little attention suddenly becomes the most important device in the MCC lineup.

Typical applications include:

• Oil & Gas — Compressor motor protection where thermal capacity and start supervision prevent expensive motor damage.
• Mining — Conveyor drive systems requiring locked-rotor and mechanical jam detection during heavy-load starts.
• Water & Wastewater — High-service pumping stations where undercurrent protection detects dry-running conditions.
• Power Generation — Boiler feed pumps requiring continuous motor health monitoring and event recording.
• Manufacturing — Process fans and crushers integrated into SCADA through Modbus RTU communications.

Field Replacement Example

During a scheduled maintenance outage at a cement plant, engineers replaced a failed legacy relay with the identical 339-E-P5-G5-H-E-S-N-N-SN-D-N configuration. Since the CT ratings, power supply, and communication interface matched the original installation, only settings verification and secondary injection testing were required. The motor was returned to service before the production shift began, avoiding another day of kiln downtime.

339-E-P5-G5-H-E-S-N-N-SN-D-N

339-E-P5-G5-H-E-S-N-N-SN-D-N

Transparency SOP: Quality Assurance & Testing

We don’t just ship boxes; we test them on actual GE Multilin relay platforms whenever possible.

• Inbound Inspection
  • Verify OEM labels and ordering code.
  • Inspect terminals, drawout mechanism, and housing.
  • Screen for counterfeit indicators and shipping damage.
• Live Rig Testing
  • Apply rated control voltage.
  • Confirm successful boot sequence.
  • Verify keypad, LCD, LEDs, USB, and RS485 communications.
• Electrical Parameter Checks
  • Validate digital inputs and output relay operation.
  • Confirm analog measurement accuracy.
  • Perform insulation checks where applicable.
• Firmware Verification
  • Record firmware revision.
  • Document hardware revision.
  • Archive relay configuration before shipment when available.
• Final QC & Packaging
  • Complete functional inspection.
  • Anti-static packaging.
  • Shock-resistant packing materials.
  • Serial number traceability.

The Veteran’s Tech Trap Guide

⚠️ Don’t assume every 339 ordering code is identical.

The ordering string defines CT ratings, power supply, communications, and mechanical construction. Two Multilin 339 relays may look identical from the front but have different hardware inside.

❗ Verify the CT ratio before energizing.

This relay is configured for 5 A phase and 5 A ground current inputs. Installing it where 1 A CTs are used will produce incorrect protection calculations.

⚠️ Save the settings first.

Before removing the old relay, upload the existing configuration using EnerVista software if the relay is still operational. Rebuilding years of protection settings from scratch is rarely enjoyable.

❗ Secondary injection testing is not optional.

Replacing the relay without verifying trip elements, CT polarity, and output contacts can create more problems than the original fault. Always perform functional testing before returning the motor to service.

Frequently Asked Questions (FAQ)

Q1. Does this relay support hot swapping?

Only if your installation uses the drawout design and follows the manufacturer’s maintenance procedure. Even then, isolate the circuit whenever practical and follow plant lockout/tagout requirements. Never assume hot removal is safe without confirming the switchgear design.

Q2. What communication protocols are included?

This configuration includes Front USB and Rear RS485 supporting Modbus RTU, DNP3.0, and IEC 60870-5-103 as standard. Ethernet and IEC 61850 require different ordering options.

Q3. Can this relay replace older GE Multilin motor relays?

In many applications, yes. The Multilin 339 was developed as a migration path for several legacy GE motor protection families. However, wiring, logic, firmware, and settings must be reviewed before installation.

Q4. Is firmware updating required?

Not necessarily. If you’re installing an identical hardware configuration, the existing firmware may be appropriate. Verify firmware compatibility before restoring archived settings, especially when replacing only one relay in a standardized fleet.

Q5. Why is this relay less expensive than purchasing directly from the OEM?

Most available units come from verified industrial surplus inventories, cancelled capital projects, or excess spare-part programs. They are genuine GE equipment, not newly manufactured products.

Q6. Is this unit genuine or refurbished?

Availability depends on inventory. Units may be supplied as Factory Sealed New Surplus, Unused Open Box, or Professionally Refurbished. The supplied condition and test documentation should always be confirmed before shipment.

Q7. What warranty is normally offered?

Most industrial automation suppliers provide a 12-month warranty against functional defects under normal operating conditions. Verify the warranty terms with the supplier before placing an order.