DS3815PDMA | Mark VI IS200 DS3815 Power Supply | New Surplus

Description

Product Introduction

The GE DS3815PDMA is a ruggedized power supply module for the Mark VI Speedtronic turbine control rack, configured for 125 VDC input with extended temperature capability and MIL-spec conformal coating. This IS200-series PSU converts a 125 VDC plant supply into the regulated voltages required by the CPU, I/O boards, and backplane. It combines the extended temperature rating of the PCPA variant with MIL-spec double-sided conformal coating, while accepting 125 VDC input—the most common turbine control bus voltage.

The DS3815PDMA 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 250W with standard filtering (<50 mV on 5V rail). The D in the suffix indicates 125 VDC input capability. The M indicates MIL-spec conformal coating. The C in the suffix indicates extended temperature rating (-40 to +75°C). This is the environmentally protected 125 VDC PSU for installations requiring corrosion resistance but not ultra-low ripple—offshore platforms, marine installations, and chemical processing areas. 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

• MIL-Spec Conformal Coating: Thick, double-sided coating fully encapsulates the PCB. Protects against salt spray, moisture, dust, and chemical vapors. Essential for offshore, marine, and corrosive industrial environments.
• 125 VDC Input Compatibility: Direct solution for standard turbine control panels with 125 VDC battery banks. No step-down transformer or separate power supply needed.
• Extended Temperature Range: Rated for -40 to +75°C ambient—5°C higher than standard PAAA variants. Uses 105°C-rated capacitors and higher-grade semiconductors.
• Full 250W Capacity: Sufficient for heavily populated 15-slot racks with multiple I/O modules.
• High-Vibration Tolerance: Components secured with industrial adhesive. Connectors are heavy-duty with gold-plated contacts for reliable connections in high-vibration environments.
• Cost-Effective Ruggedized Solution: The PDMA provides MIL-spec coating and extended temperature rating at a lower cost than the PDLC (which adds enhanced filtering). If you don’t need ultra-low ripple but need environmental protection, this is the most economical choice.
• Full Load Bank Test at Elevated Temperature with Coating Verification: Every unit runs on our test rig at +75°C ambient for 24 hours, pulling full 250W load. We perform UV inspection to verify coating integrity. Capacitors replaced on units manufactured before 2015.
• Surplus/Refurbished with 1-Year Warranty: New surplus (original GE packaging) or professionally refurbished. 1-year warranty, 30-day return.

Frequently Asked Questions (FAQ)

Q: What’s the difference between DS3815PDMA and DS3815PDLA?

Filtering and coating. The PDMA has MIL-spec conformal coating but standard filtering (<50 mV on 5V). The PDLA has enhanced filtering (<20 mV on 5V) but no conformal coating. Both accept 125 VDC input, have extended temperature rating (-40 to +75°C), and deliver 250W. Choose PDMA for corrosive environments. Choose PDLA for sensitive analog measurements in clean environments.

Q: What’s the difference between DS3815PDMA and DS3815PDLC?

Filtering. The PDLC has enhanced filtering (<20 mV on 5V) in addition to MIL-spec coating. The PDMA has standard filtering (<50 mV on 5V) with MIL-spec coating. Both accept 125 VDC input, have extended temperature rating, and deliver 250W. The PDLC is the premium version—it combines environmental protection with ultra-low ripple. The PDMA is the cost-effective ruggedized version for applications that don’t need ultra-low ripple.

Q: What’s the difference between DS3815PDMA and DS3815PCMA?

Input voltage. The PDMA accepts 125 VDC input. The PCMA accepts 48 VDC input. Both have MIL-spec conformal coating, extended temperature rating (-40 to +75°C), standard filtering, and 250W capacity. They are not interchangeable—choose based on your plant’s available DC supply. If you have 125 VDC battery banks (most common in turbine panels), you want the PDMA. If you have 48 VDC telecom-style power, you need the PCMA.

Q: What’s the difference between DS3815PDMA and DS3815PAAA?

Temperature rating and coating. The PDMA has extended temperature rating (-40 to +75°C) and MIL-spec conformal coating. The PAAA has standard temperature rating (-40 to +70°C) and no coating. Both accept 125 VDC input, have standard filtering, and deliver 250W. The PDMA is the ruggedized version for harsh environments. The PAAA is the standard workhorse for clean, climate-controlled environments.

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

Yes—the PDMA delivers 250W total, sufficient for a fully populated rack in most configurations. At temperatures above 65°C, derating applies. At 75°C, you lose approximately 25% of capacity—down to about 187W. Calculate your actual load and cabinet temperature. The conformal coating doesn’t affect electrical capacity.

Q: What’s the correct polarity for the 125 VDC input?

The input terminals are labeled “+” and “−” on the front panel. Polarity matters—reverse polarity will trigger the internal protection diode and the PSU will not power up. Correct the polarity and it will start normally. The PDMA has gold-plated terminals for corrosion resistance. Double-check your wiring before applying power.

Q: Can I run two PDMA units in redundant configuration?

Yes—the PDMA supports active current sharing for N+1 redundancy. Two units in parallel will each run at approximately 50% load, reducing internal heating and extending component life. In harsh environments, redundancy is critical. We can supply matched pairs tested for current sharing across the full temperature range. Both units receive the same MIL-spec coating and environmental verification.

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 250W (or the derated capacity at high temp). If red is on, the PSU is overtemperature—check cabinet ventilation. The conformal coating does not affect LED visibility.

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

No user-replaceable fuse. The PDMA uses solid-state current limiting. If the PSU doesn’t power up, it’s either input power missing, wiring error, or internal failure. Do not open the casing—internal capacitors hold charge. The MIL-spec coating makes field repair even more difficult. Send it to us for evaluation.

Q: Can I use a standard 125 VDC DIN-rail power supply instead of this board?

No. The DS3815PDMA is a backplane-specific module with proprietary connector and output ramp timing. A DIN-rail supply won’t match the timing and won’t survive harsh environments without MIL-spec coating. Stick with the original board.

Q: Is the PDMA worth the premium over the PAAA?

That depends on your environment. If your cabinet is in a clean, climate-controlled room, the PAAA is sufficient and costs significantly less. If you’re in a corrosive environment (offshore, marine, chemical processing) with 125 VDC input and don’t need ultra-low ripple, the PDMA is the right choice. The MIL-spec coating will prevent corrosion-related failures that would otherwise occur within 12-24 months.

Q: I’m offshore with 125 VDC and don’t have sensitive analog. Should I choose PDMA or PDLC?

The PDMA is the more cost-effective choice for your application. You get the MIL-spec coating for corrosion protection and the extended temperature rating for the hot turbine deck. You don’t need the enhanced filtering of the PDLC because you don’t have sensitive analog measurements. Save the budget and buy the PDMA. If your analog measurements become sensitive in the future, you can upgrade later.

Q: Is the PDMA compatible with standard Mark VI racks?

Yes—it fits the same IS200 backplane slot as all other DS3815 PSU variants. No adapter plates or mechanical modifications needed. Direct swap for any other DS3815 PSU—same dimensions, same connector, same terminal layout. No software changes required.

Q: How do I verify the conformal coating is intact?

We perform UV light inspection on every refurbished PDMA unit. The coating fluoresces under UV, making any cracks, bubbles, or missing areas visible. We include a detailed UV inspection report with every shipment, including photos showing complete coverage. In the field, you can do a quick visual inspection under a UV flashlight—any dark spots indicate missing coating. If you find damage, the board should be recoated before installation.

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