What the IS230SNRLH2A Actually Does (In Plain Language)

The IS230SNRLH2A is a discrete relay output module designed for GE’s Mark VIe control system. It provides 16 independent electromechanical relay outputs, each rated for 250 VAC / 30 VDC at 5 amps. These outputs are used to drive external field devices such as:

• Solenoid valves (trip oil, fuel shutoff, steam admission)

• Motor starters (cooling fans, lube oil pumps)

• Alarm annunciators and warning lights

• Actuator enable signals

• Interlock bypass relays

Unlike solid-state output modules that use transistors or triacs, the IS230SNRLH2A uses physical relays with gold-plated contacts, offering superior isolation and the ability to switch both AC and DC loads. This makes it the go-to choice for safety-related and high-integrity circuits where a hard contact closure is mandatory per plant wiring standards.

Technical Profile – Not Your Usual Table

Instead of listing a dry spec table (you can find that in the datasheet), let me break down the five critical engineering characteristics that matter most to you as a maintenance or procurement professional:

1. Contact Configuration – Form A (Normally Open)
All 16 channels are Form A (SPST-NO). Each relay is rated for 5 A resistive at 250 VAC or 30 VDC. For inductive loads (solenoids, contactors), we strongly recommend external snubber circuits or varistors—the board itself does not include internal suppression, which is actually a plus because you can tailor the suppression to your specific load.

2. Switching Speed – Not Fast, But Purposeful
The typical operate time is 8 ms, and release time is 6 ms. This is intentionally "slow" because relay outputs are not meant for high-speed PWM or fast-cycling applications—they are for discrete on/off commands that change once every few seconds or minutes. If you need faster switching, you should look at the IS230STAIH2A analog output or IS230TDTAH2A triac output variants.

3. Isolation – 2500 V RMS (Optical)
Each channel is opto-isolated from the backplane and from each other. This is non-negotiable for industrial environments where ground potential differences and transient surges are common. We have tested the isolation withstand voltage at 3 kV for 1 minute—well above the spec—and every unit we ship passes that test.

4. Diagnostic Feedback – The Hidden Gem
The IS230SNRLH2A provides echo feedback for each relay—meaning the module reads back the actual contact status and compares it to the commanded state. If the relay fails to pick up or drops out unexpectedly, the module sets a "Relay Mismatch" alarm in the controller. This diagnostic feature is often overlooked, but it is a lifesaver for predictive maintenance. We include a diagnostic report with every used/refurbished unit we sell, showing that all 16 echo paths are functional.

5. Power Consumption – 5 VDC Backplane Only
Unlike some older modules that require both 5 V and 24 V external supplies, the IS230SNRLH2A draws all its power from the Mark VIe backplane's 5 V rail. Typical consumption is 600 mA maximum. This simplifies installation—just plug it in and the rack supplies everything.

Which Systems Use This Module?

You will find the IS230SNRLH2A in:

• GE Mark VIe turbine control panels (both gas and steam)

• EX2100e excitation control retrofits

• Water injection skids and fuel gas conditioning units

• Compressor station PLC upgrade projects that retain GE I/O

It is a direct replacement for older part numbers like IS200SNRLH1A and IS215SNRLH2A, with the key improvement being enhanced coil life (rated for 100,000 operations at full load vs. 50,000 on the H1A variant). So if you are still running H1A boards, moving to the H2A effectively doubles your relay service life.

The Problem We Keep Seeing – And How We Solve It

In the field, the most common failure mode is not the relay coil burning out—it is contact welding or pitting due to high inrush currents from capacitive loads (e.g., long cables, LED lighting drivers). GE's specification assumes a purely resistive load, but real-world plants rarely have that luxury.

That is why we do something that most suppliers do not: before shipping any IS230SNRLH2A, we test each relay channel with a 5 A inductive load (cos φ = 0.75) for 100 cycles to verify contact bounce and arc extinction. We also measure the contact resistance (target ≤ 50 mΩ) and record it on a certificate of conformance. If a unit fails our in-house stress test, it goes back to our refurbishment line—we never pass questionable stock to customers.

For new units (we have both new and factory-refurbished available), we provide the original GE packing slip and date code. For refurbished units, we offer a 24-month warranty—double the standard industry practice—because we stand behind our reconditioning process which includes relay replacement with brand-name Omron components (same as GE's original BOM).

Pricing, Terms, and Urgent Supply

Here is our current offer structure:

We also offer an emergency swap program: if your module fails and you cannot afford downtime, we can cross-ship a replacement unit before you return the failed one (subject to credit approval). This program has saved our clients an average of 14 hours of outage time—and in power generation, that translates to roughly $50,000–$200,000 in recovered revenue per event.

Why Choose Us Over GE Direct or Other Distributors?

Three reasons, and they are distinct from what we offered on our previous product post:

1. We stock both new and refurbished grades – giving you budget flexibility. Not every plant has capital expenditure approved for new hardware; our refurbished units meet or exceed original performance at 77% of the new price.

2. We offer on-site replacement consultation – our field application engineers can video-call you during installation to verify pin-out, fuse ratings, and cabinet grounding. No other distributor does that.

3. We maintain a dedicated spare pool for emergency contracts – if you sign a 1-year consignment agreement (minimum 5 modules), we guarantee that you have priority access to our stock, even if the rest of the market is depleted. This is ideal for multi-turbine sites or islanded power stations that cannot afford long outages.

Compatibility & Interchangeability Notes

• Firmware: The IS230SNRLH2A does not require user-loaded firmware—it is a dumb I/O module controlled entirely by the UCSB controller. However, the controller's I/O configuration file must have the correct module type (SNRL) assigned. If you are replacing an older SNRLH1A, the H2A is a drop-in replacement with no configuration changes needed.

• Fuse protection: Each relay output has a built-in PTC fuse (resettable) rated at 6 A. If you trip a fuse due to a short, it will auto-reset after cooling—but we recommend investigating the root cause rather than relying on the PTC.

• Front LED indicators: There are 16 green LEDs (one per channel) showing the commanded state, plus a red "Module OK" LED. If the red LED flashes, it indicates a backplane communication error—check your rack's power supply and terminator.

A Quick Word on Our Refurbishment Process

Since many clients ask: our refurbishment of the IS230SNRLH2A includes:

• Ultrasonic cleaning of the PCB to remove flux and dust.

• Replacement of all electrolytic capacitors (aging leads to ripple and false triggers).

• Relay contact burnishing and resistance measurement.

• 48-hour burn-in at 60°C ambient to weed out infant-mortality failures.

• Final calibration check using GE's proprietary diagnostic tool (ToolboxST I/O test).

We document each step with photos and test logs, which we can share upon request. Transparency is our policy—no black-box refurbishment.

Stock Alert – Limited Quantity for Immediate Shipment

As of this writing, we have 19 brand-new and 32 refurbished IS230SNRLH2A modules in our US warehouse. We typically move 8–10 units per week, especially from nuclear and combined-cycle plants that are stocking up for autumn overhauls. At this pace, the new units will be gone in two weeks.

We are not asking you to buy today—we are asking you to check your spares cabinet right now. If you have fewer than two working spares of this module, you are at risk. Send us an email or call our hotline, and we will reserve units for you without obligation for 5 business days.

Final Thoughts

The IS230SNRLH2A is a workhorse—not glamorous, but absolutely critical. When it fails, your turbine stops. That is a fact. Our job is to make sure that when the failure happens, you have a replacement module in your hand within 24 hours, at a fair price, with documentation that gives you confidence.