Description
The GE Multilin 469-P5-H1-A20-T-H is an industrial, microprocessor-based protection relay designed for the comprehensive management, diagnostics, and protection of medium-to-large horsepower synchronous and induction motors. Operating within power distribution and critical motor control center (MCC) architectures, this unit integrates three-phase overcurrent, thermal modeling, underfrequency, and ground fault protections into a single chassis.
Commercial Availability & Terms
- Condition: New Original (Factory Sealed Surplus) or Refurbished (Tested and Calibrated)
- Warranty: 12-Month Comprehensive Technical Warranty
- Availability: In Stock
- Standard Lead Time: Ships within 1–2 business days via global express couriers
- Pricing Note: Price is subject to component availability and market demand. Contact our engineering sales department for a firm, written quote.
Part Number Configuration Breakdown (469-P5-H1-A20-T-H)
The alphanumeric coding scheme specifies the exact hardware options, current transformer (CT) inputs, control power levels, and physical enhancements built into this specific relay configuration:
- 469: Base Series Motor Management Relay Platform
- P5: Phase Current Inputs: 5 A secondary phase CT inputs (standard configuration)
- H1: Control Power Supply: High-voltage range (90–300 V DC / 70–265 V AC, 50/60 Hz)
- A20: Analog Outputs: Four 4–20 mA analog outputs (used for remote instrumentation routing)
- T: Enhanced Display: Includes a Vacuum Fluorescent Display (VFD) enhanced screen layout
- H: Harsh Environment Coating: Conformal-coated circuit boards for corrosion protection (ISA-S71.04 Class G3 severity compliance)
Technical Specifications
| Parameter | Value / Specification |
| Phase Current Inputs | 5 A secondary CT input; 0.05 to 20 \times CT primary tracking range |
| Ground Current Inputs | 1 A or 5 A secondary inputs, plus 50:0.025 ZSCT (Zero Sequence CT) path |
| Voltage Inputs | 3-phase VT (Voltage Transformer) connection up to 600 V AC directly |
| Analog Inputs | Four 4–20 mA channels (or 0–1 mA) for process parameters like vibration/pressure |
| Output Relays | 6 Form C outputs (Trip, Alarm, Aux 1-3, Service); max 10 A continuous resistive |
| Communication Ports | Rear RS485/RS422 (Modbus RTU up to 19,200 bps), Front RS232 programming port |
| Frequency Tracking | 20 to 65 Hz dynamic monitoring for variable frequency drive (VFD) compatibility |
| Enclosure Rating | Front panel IP54 / NEMA 12 protection level |
Field Integration & Thermal Modeling Constraints
When deploying or upgrading a system using the 469-P5-H1-A20-T-H, engineers must adhere to specific field parameters:
- Thermal Capacity Used (TCU) Tracking: The core protection engine relies on a mathematical thermal model that calculates the stator and rotor thermal strain based on current, unbalance, and RTD feedback. If the relay reaches 100% TCU, it will assert a lock-out condition. Ensure that the motor manufacturer’s thermal limit curves (both hot and cold stall times) are accurately typed into the setpoint registers to prevent nuisance tripping during high-inertia startups.
- CT Polarity and Phase Rotation: Correct polarity of the phase CT connections is critical for the unbalance and negative-sequence current calculations. Reversing a single CT polarity will cause the relay to see false current unbalance, leading to a premature thermal trip. Verify that the phase rotation setting (ABC or ACB) in the software configuration matches the actual incoming physical line rotation.
- Grounding and Shielding of RTD Lines: The relay supports up to 12 RTD inputs (typically Pt100 or Ni100) embedded in the motor stator slots and bearings. All RTD cables must be twisted, shielded pairs. Terminate the shields strictly at the 469 relay chassis grounding terminal bar; do not tie the shields to earth at the motor terminal box to avoid introducing common-mode noise into the temperature readings.
Frequently Asked Questions
Can this specific relay be used on a 24 V DC control power circuit?
No. The H1 suffix in the part number indicates the high-voltage power supply option, requiring at least 90 V DC or 70 V AC to boot the internal processing boards. Connecting this module to a 24 V DC or 48 V DC battery bank will result in a total failure to power up. For low-voltage direct current systems, an L1 variant must be specified.
What is the exact function of the “H” suffix at the end of the part number?
The H suffix represents factory-applied conformal coating on the internal printed circuit board assemblies. This chemical barrier provides extra insulation against moisture, conductive dust, and corrosive gases (such as hydrogen sulfide or chlorine). It is a requirement for relays installed in harsh industries like pulp and paper mills, chemical processing facilities, or offshore oil platforms.
How do you bypass a “Motor Lock-out” condition after a thermal trip?
If the relay trips the motor due to thermal overload, it enforces a cooling period based on the configured motor cooling time constants. In an emergency plant scenario where the motor must be restarted immediately despite the thermal penalty, a hardware or software bypass can be initiated. This requires navigating to the execution command menu via the front keypad (or EnerVista software) and entering the authorized security passcode to manually clear the thermal capacity registers back to 0%. Doing so risks motor damage if the actual winding temperature remains elevated.
