DS3800NRTB1A1A | Replacement for NRTB Rev A Output Board

Description

Product Introduction (Anti-Template)

A digital output board that’s been installed in thousands of cabinets worldwide—that’s the DS3800NRTB1A1A. This is the base revision of GE’s alternative-layout digital output termination board, built for plants that prefer a different terminal block grouping than the standard NRTA. The electrical design is the same as the NRTA: 32 channels, 0.5A per channel, flyback diode protection, and green LEDs that show the output state. The only difference is the terminal block arrangement—some plants standardize on this layout because it matches their marshalling cabinet wiring.

What you get is a field-proven board with over a decade of service history. The 1A1A designation tells you it’s the original revision—standard PCB material, standard operating temperature (0-55°C), and standard screw-clamp terminals. A West Coast refinery has been running these boards in their control room for 11 years without a single failure. The board just works.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

What’s the difference between the NRTB1A1A and the NRTA?
Electrical performance is identical—32 channels, 0.5A per channel, flyback diodes. The difference is the terminal block layout. The NRTA has one arrangement; the NRTB has an alternative arrangement. The 1A1A suffix indicates this is the base revision: standard PCB, standard terminals, standard temperature range.

Why would I choose the NRTB over the NRTA?
If your existing wiring diagram references the NRTB, stick with it. Some plants standardized on the NRTB because the channel grouping matches their cable tray routing or marshalling cabinet layout. If you’re starting from scratch, the choice between NRTA and NRTB is arbitrary—either works. Just pick one and stick with it.

Can I swap an NRTA for an NRTB without rewiring?
No. The terminal block channel numbering is different. If you plug an NRTB into a rack wired for an NRTA, the outputs won’t map correctly. You’d need to re-terminate all 32 channels—a 2-3 hour job. Match the board type to your wiring diagram.

What’s the maximum current per channel?
0.5A continuous per channel, with 1.0A peak for inductive loads. The total board current is 8A. For loads above 0.5A, use an external interposing relay. The board will overheat if you exceed 8A total.

Does the NRTB1A1A have flyback diode protection?
Yes, each channel has a flyback diode. This clamps the voltage spike from de-energizing a solenoid or relay, protecting the output module. If a diode fails (open circuit), the module will eventually fail. Diodes aren’t field-replaceable—replace the board.

Can I hot-swap the NRTB1A1A?
No. It’s connected to live field loads. Pulling it while powered can cause arcing and damage the output module. Power down the rack, swap, and power back up.

What do the LED indicators show?
Green: output ON. Off: output OFF. The LEDs work even if the I/O module is powered down—a useful diagnostic tool.

What’s your test procedure?
Our inbound test:

• Visual: inspect terminal blocks, bent pins, and flyback diodes for discoloration.
• Diode check: each flyback diode must read 0.6V forward, open reverse.
• Current test: apply a 0.5A load to each output—voltage drop under 0.5V.
• Isolation: 500V DC between adjacent channels—must exceed 10MΩ.
• LED test: verify green LEDs illuminate with 24V DC applied.

We reject about 4% of inbound boards—mostly for failed flyback diodes or cracked terminal blocks.

What’s the most common field issue?
Overtightening terminal screws (cracks the blocks) and failed flyback diodes from oversized solenoids (drawing over 0.5A). Use a torque screwdriver (0.5 Nm) and check your solenoid data sheets.

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TRLC0NEX 3625
TRICONEX 3625
GE 8851-LC-MT
BENTLY 1900/65A-01-00-01-00-00