DS3815PACA | GE Speedtronic IS200 Power Board | Ready to Ship

Description

Product Introduction

The GE DS3815PACA is a power supply module for the Mark VI Speedtronic turbine control rack, configured for 48 VDC input. This IS200-series PSU converts a 48 VDC plant supply—common in telecommunications-backed turbine installations—into the regulated voltages required by the CPU, I/O boards, and backplane. It’s the direct equivalent of the DS3815PAAA in output capacity but accepts 48 VDC instead of 125 VDC or 240 VAC.

The DS3815PACA provides three output rails: 48 VDC for the CPU bus (passed through with regulation), 24 VDC for field device loop power, and 5 VDC for logic-level circuits. Total output capacity is 250W—identical to the PAAA variant. 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. This is the go-to PSU for plants with existing 48 VDC battery banks.

Key Technical Specifications

Key Selling Points & Differentiators

• 48 VDC Input Compatibility: Direct solution for plants with 48 VDC battery banks—common in telecom-backed turbine installations, offshore platforms, and sites with centralized DC distribution. No step-up transformer or separate power supply needed.
• 250W Total Capacity: Same output capacity as the PAAA variant—full power for 15-slot racks with multiple I/O modules. Handles heavy loads without derating up to 60°C ambient.
• Efficient Conversion: >86% efficiency at full load—runs cooler than the PAAA variant (which runs ~85%). In tight cabinets, every degree matters.
• 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 48V output is regulated, not just a pass-through from input.
• Full Load Bank Test: Every unit runs on our test rig pulling full 250W load for 24 hours. We monitor all three outputs under dynamic load stepping and verify hold-up time exceeds 15 ms. Input reverse polarity and transient response 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 DS3815PACA and DS3815PAAA?

Input voltage only. The PAAA accepts 125 VDC or 240 VAC and delivers 250W. The PACA accepts 48 VDC only and delivers the same 250W. They are not interchangeable—if you have a 48 VDC plant supply, the PACA is your only option. If you try to feed 125 VDC into a PACA, you’ll exceed the maximum input voltage (60V) and destroy the input stage. Check your cabinet’s power distribution carefully before ordering.

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

Yes—the PACA delivers 250W total, which is sufficient for a fully populated rack in most configurations. A full 15-slot rack with CPU, multiple analog I/O, thermocouple boards, relay outputs, and communications modules typically draws 180-200W. You have 50-70W of headroom, which is within the recommended 20% margin. Calculate your actual load using individual module power specs from the IS200 series datasheet. If you’re running redundant communications or special high-power modules, verify the total.

Q: What’s the correct polarity for the 48 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. However, the protection diode is not infinite—repeated reverse polarity events can stress and eventually fail it. Double-check your wiring before applying power.

Q: My current DS3815PAAA runs hot. Can I swap to PACA without changing anything else?

Mechanically, yes—it fits the same rack slot. But you must change the input wiring. The PAAA has terminals for 125 VDC or 240 VAC; the PACA has terminals for 48 VDC only. You’ll need to connect your 48 VDC supply to the PACA’s input terminals. Do not connect 125 VDC or 240 VAC to the PACA. Beyond that, the backplane connections are identical—the CPU sees the same status signals and power rails. No software changes required.

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

Yes—the PACA supports active current sharing for N+1 redundancy. Connect two units in parallel using the same 48 VDC input bus. The PSUs automatically balance the load. If one fails, the other carries the full 250W load. We offer matched pair testing to ensure current sharing within ±5% across the load range. This is highly recommended for critical turbine applications where a PSU failure means an unplanned shutdown.

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. Check for failing modules or reduce the load. If red is on, the PSU is overtemperature—check cabinet ventilation and ambient temperature. The PACA runs efficiently but still needs adequate airflow in high-ambient conditions.

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

No user-replaceable fuse. The PACA 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 48 VDC DIN-rail power supply instead of this board?

No. The DS3815PACA 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: What’s the advantage of 48 VDC input over 125 VDC or 240 VAC?

Efficiency and availability. At 48 VDC, the PACA runs at >86% efficiency—higher than the PAAA. If your plant already has a 48 VDC battery bank (common in telecom or offshore), you avoid the cost of a separate 125 VDC supply or AC distribution. Also, 48 VDC is inherently safer to work with than 125 VDC—lower shock risk during maintenance. The trade-off is higher input current (6.5A vs. 4A), so your DC bus wiring needs to be sized accordingly.

Q: I’m upgrading from an older Mark V system. Does the PACA work with Mark VI racks?

Yes—the PACA is specifically designed for Mark VI/IS200 racks. Mark V used different power supplies (e.g., the DS200 series). The mechanical dimensions, backplane connector, and voltage rails are different. Do not attempt to use a Mark V PSU in a Mark VI rack. If you’re migrating from Mark V to Mark VI, you’ll need a complete PSU replacement along with the new processor and I/O boards.

BENTLY NEVADA 3500/42-01-00
GE IC754VSI12CTD
ABB NBIO-21C
SIEMENS JXD63M350