GE DS2020FECNRX015A | Field Excitation Board | New Original

Description

Product Introduction

The GE DS2020FECNRX015A functions as the Field Excitation Control (FECN) module within the Mark VIe control platform, providing integrated field excitation control with redundant firing channels for critical medium generator applications up to 15 A field current. This module interfaces with the Mark VIe controller via ISBus communication and offers 4 configurable analog inputs, 2 analog outputs, and dedicated field excitation outputs for controlling generator field current, voltage, and reactive power.

The model number breaks down as: FECN (Field Excitation Control), RX015 (15 A field excitation output rating with redundant firing channels), A (Revision A). The primary differentiator is the combination of 15 A capacity and redundant firing channels—the RX015 provides the reliability of dual-channel firing in a module designed for medium generators where even a brief loss of excitation would be unacceptable.

Key Technical Specifications

Key Selling Points & Differentiators

• 15 A Capacity with Redundancy: 15 A continuous output with dual-channel firing and auto-switchover—provides both capacity and protection for critical medium generators.
• Redundant Firing Channels (RX Variant): Dual-channel firing with auto-switchover—if the primary firing channel fails, the module automatically switches to the backup channel within 5 ms, ensuring continuous excitation control.
• Cost-Effective Redundancy: Provides redundancy for generators with field currents between 10 A and 15 A—a cost-effective alternative to the larger RX025 and RX050 modules.
• Integrated Excitation Power Stage: Built-in 15 A SCR bridge and protection—eliminates the need for a separate excitation power module.
• Combined Excitation and Analog I/O: Integrated 4 analog inputs and 2 analog outputs—provides sensor inputs and control outputs without additional I/O modules.
• Comprehensive Field Protection: Overcurrent, overvoltage, under/over frequency, and field loss detection—provides complete protection for the generator field.
• Field Diagnostics: Field current and voltage monitoring, bridge health assessment, and SCR health monitoring—enables predictive maintenance.
• Full Live Test Certification: Each unit undergoes a 48-hour burn-in with full field output simulation (15 A), analog I/O verification, ISBus communication testing, redundancy switchover validation, and protection feature verification. We log the MAC ID, calibration data, and diagnostic baselines for traceability.
• Direct Drop-In Replacement: Form-fit-function compatible with DS2020FECNRX015 and earlier FECN revisions. Existing wiring and terminal assignments remain unchanged.
• 90-Day Warranty: Includes technical support and cross-ship replacement within 24 hours if the module fails to provide excitation output, reports incorrect analog values, protection circuits fail to operate, diagnostics report false faults, or redundancy switchover fails.

Frequently Asked Questions (FAQ)

Q1: What’s the difference between the DS2020FECNRX015A and the DS2020FECNRP015A?

The RX015A has redundant firing channels (dual-channel with auto-switchover), while the RP015A is a single-channel module. Both modules provide 15 A output. The RX015A is designed for critical generators where a firing channel failure would cause an unacceptable outage. The RP015A is for non-critical applications where a single-channel system is acceptable. The RX015A is approximately 20-25% higher in cost due to the redundancy.

Q2: What’s the maximum generator size (MW) for the FECNRX015A?

The maximum generator size depends on the field current requirement at rated load. The RX015 provides 15 A continuous. For a typical generator, field current at rated load is approximately 1-2 A per MW (for brushless excitation systems) or 2-4 A per MW (for static excitation systems). As a general guideline, the RX015 is suitable for generators up to 8-15 MW. It’s commonly used for: (1) critical steam turbines (8-15 MW), (2) combustion turbines (8-15 MW), (3) critical industrial generators (8-12 MW), and (4) emergency generators in critical facilities.

Q3: Does the FECNRX015A require forced air cooling at full load?

At 15 A output, the module generates approximately 45-55 W of heat. Natural convection is typically sufficient, but we recommend ensuring adequate airflow in the cabinet (at least 15 CFM across the module) and maintaining ambient temperature below 50°C. The module does not include a fan. The thermal warning LED triggers at 75°C internal, and the module will derate if temperature exceeds 85°C. For high-density cabinets or ambient temperatures above 50°C, we recommend forced air cooling.

Q4: How does the redundancy (dual-channel firing) work in the RX015A?

The RX015A has two independent firing channel circuits (Channel A and Channel B). Under normal operation, Channel A is active and Channel B is in standby. The module continuously monitors the firing pulse integrity. If the module detects a firing failure on Channel A, it automatically switches to Channel B within 5 ms. The switchover is seamless—the field current is not interrupted. The module logs the switchover event and reports the active channel status via ISBus. We recommend testing the switchover during commissioning.

Q5: The bridge health warning shows on Channel B, but Channel A is active. Should I replace the module?

A bridge health warning on a channel that is not currently active does not require immediate replacement. The warning indicates that the SCRs in the inactive channel are showing signs of degradation—likely due to thermal stress or aging. Since the active channel is healthy, the generator will continue to operate normally. However, you should plan to replace the module during the next planned outage because the inactive channel is your backup. We recommend replacement within 6-12 months of a bridge health warning.

Q6: The RX015A shows a firing channel switchover in the event log, but the module is still running normally. Should I investigate?

Yes. Any automatic switchover should be investigated. The switchover indicates that the primary firing channel (Channel A) experienced a failure that required the backup channel to take over. Even though the module is still running normally, the primary channel is degraded. Investigate: (1) check the firing pulse integrity logs, (2) check the gate drive circuit components, (3) check the SCR bridge health. Schedule a maintenance inspection to identify the root cause. If the primary channel failure cannot be resolved, replace the module during the next outage.

Q7: What’s the typical lead time for the FECNRX015A, and do you recommend stocking spares?

The FECNRX015A is a moderately stocked module—we maintain 5-8 units in inventory. Standard lead time for orders of 1-5 units is 1-2 weeks due to the specialized redundancy testing and 48-hour burn-in. For critical generators, we recommend stocking one spare module per site. If you have a fleet of 10+ turbines, a 10% spare ratio is standard practice. If you need immediate delivery and the RX015A is out of stock, consider the RP015A as a substitute—it has the same current capacity but lacks redundancy. Call our support line for expedited options.

XYCOM 1840
XYCOM 1300HAZ
XYCOM 121470-001
XVME-9403