DS3815PABA1A1B | GE Mark VI IS200 DS3815 PSU | In Stock

Description

Product Introduction

The GE DS3815PABA1A1B is a power supply module for the Mark VI Speedtronic turbine control rack, configured for 24 VDC input. This IS200-series PSU converts a 24 VDC plant supply into the regulated voltages required by the CPU, I/O boards, and backplane. Unlike the 125 VDC / 240 VAC variants, this unit is designed for installations where only 24 VDC is available—typically smaller turbine packages or retrofit applications.

The DS3815PABA1A1B provides three output rails: 48 VDC for the CPU bus, 24 VDC for field device loop power, and 5 VDC for logic-level circuits. Total output capacity is 150W. The 1A1B suffix indicates a specific revision with enhanced input filtering—this variant includes additional EMI suppression components on the DC input to reduce conducted emissions. Critical for installations where the control panel shares a power bus with VFDs or other noisy loads. The module includes the same backplane-specific connector as all Mark VI power supplies, sliding directly into the rack and communicating status (voltage good, overcurrent, overtemperature) to the CPU via discrete signals.

Key Technical Specifications

Key Selling Points & Differentiators

• Enhanced Input EMI Filtering: The 1A1B revision includes additional filtering components on the 24V input. This suppresses conducted emissions and protects against voltage spikes from VFDs, solenoids, and other inductive loads sharing the same DC bus. GE added this specifically for plants with dirty DC power.
• 24 VDC Input Compatibility: Direct solution for plants with 24 VDC control power already distributed. No step-up transformer or separate 125 VDC supply needed. Reduces installation cost and cabinet complexity.
• Direct Mark VI Backplane Interface: Plugs directly into the IS200 rack—same mechanical and electrical fit as other PSU variants. The CPU reads status via backplane signals without any configuration changes.
• Triple Isolated Outputs: Galvanic isolation between 48V, 24V, and 5V rails prevents a fault on one rail from collapsing the others. The 24V field loop output is independently regulated, not just passed through from input.
• Full Load Bank Test with Noise Measurement: Every unit runs on our test rig pulling full 150W load for 24 hours. We measure output ripple on all three rails and verify hold-up time exceeds 8 ms. Input reverse polarity protection verified on every unit.
• Surplus/Refurbished with 1-Year Warranty: New surplus (original GE packaging) or professionally refurbished. Electrolytic capacitors replaced on units manufactured before 2015. 1-year warranty, 30-day return.

Frequently Asked Questions (FAQ)

Q: What’s the difference between DS3815PABA and DS3815PABA1A1B?

Input filtering and component revision. The PABA1A1B includes enhanced EMI filtering on the 24V input—common-mode chokes and additional capacitors. This matters if your 24V bus is shared with variable frequency drives, large contactors, or UPS systems with dirty output. The PABA lacks these components. Functionally, they deliver the same 150W output, but the 1A1B is more tolerant of noisy DC supplies. If you’ve had unexplained CPU resets or analog drift, this revision may resolve them.

Q: Can I use this PSU to power a full 15-slot Mark VI rack?

It depends on your total load. The PABA1A1B delivers 150W total. A fully populated rack with CPU, multiple analog I/O, thermocouple boards, relay outputs, and redundant communications can draw 180-200W. In that scenario, the PSU will overload and eventually trip. We’ve seen customers run 12-slot racks successfully with this PSU. Calculate your backplane load using the individual module power specs from the IS200 series datasheet. Leave a 20% margin—don’t exceed 120W continuous for reliable operation.

Q: What’s the correct polarity for the 24 VDC input?

The input terminals are labeled “+” and “−” on the front panel. Polarity matters—reverse polarity will trigger the internal protection diode, but it will not damage the PSU. The board will simply not power up. Correct the polarity and it will start normally. That said, repeated reverse polarity events can stress the protection circuit, so double-check before applying power.

Q: My current DS3815PABA is from 2005. Should I replace the capacitors proactively?

Yes, and we do this on every refurbished unit. The input filtering capacitors age faster in 24 VDC applications because the input current is higher (8A vs. 4A on the PAAA). At 8A, the ripple current stress on the caps is significant. After 10-15 years, capacitance drops, hold-up time shortens, and you can get CPU resets during input voltage dips. We replace all electrolytic capacitors with fresh 105°C-rated components and test the rail stability. A serviced PABA1A1B is more reliable than an unserviced unit from the same era.

Q: Can I hot-swap this PSU with the rack powered on?

Not recommended. The backplane connector is designed for live insertion, but the 48V output can spike during insertion. We’ve seen the CPU lock up even on redundant PSU configurations. The correct procedure: power down the rack, swap the PSU, then power up. If you’re running redundant PSUs and one fails, you can swap the failed unit with the rack powered on—the online PSU will carry the load. For single PSU installations, never hot-swap.

Q: What are the status LED patterns indicating?

Three LEDs on the front panel: DC OK (green), Overload (yellow), Overtemperature (red). Normal: green steady, yellow off, red off. If yellow is steady, you’re in current limit—your rack is drawing more than 150W. Check for failing modules or reduce the load. If red is on, the PSU is overtemperature—check cabinet ventilation and ambient temperature. This PSU is convection-cooled, so cabinet airflow matters more than fan-cooled supplies.

Q: Is there a fuse on this board that I can replace in the field?

No user-replaceable fuse. The PABA1A1B uses solid-state current limiting and reverse polarity protection. If the PSU doesn’t power up, it’s either input power missing, a wiring error, or internal failure. Do not open the casing—internal capacitors hold charge even after power removal. Send it to us for evaluation or scrap it properly.

Q: Can I use a standard 24 VDC DIN-rail power supply instead of this board?

No. The DS3815PABA1A1B is a backplane-specific module with a proprietary connector and output ramp timing. The CPU expects the 48V, 24V, and 5V rails to rise within a specific sequence and timing window. We’ve seen customers wire a DIN-rail supply directly to the backplane—it works briefly, then the CPU watchdog trips during startup because the 5V rail rose 200 ms after the 48V rail. GE engineered this timing for a reason. Stick with the original board.

Q: How does the enhanced filtering help with VFD noise on the DC bus?

The 1A1B revision adds a differential-mode choke and additional X/Y capacitors on the input. When a VFD or other inverter runs from the same 24V bus, it injects high-frequency switching noise—typically 2-20 kHz. Standard PABA boards can pass that noise through to the 5V logic rail, causing analog reading jitter or intermittent communication errors. We’ve had customers solve persistent “phantom” speed fluctuations by switching from the standard PABA to the 1A1B revision. It’s not a miracle cure, but it helps significantly.

ELAU MC-4/11/10/400
ABB PFEA112-20
TRICONEX 3008