IS230TRLSH1B Mark VIe | Replacement Relay Terminal Block for GE

Description

Product Introduction

The solenoid shorted—just a piece of debris in the valve, nothing major. But the 24 VDC power supply was rated for 10 A, and the short pulled 8 A through the relay, welding the contacts shut. The valve stayed open, the turbine oversped, and the emergency stop had to be manually pressed. The TRLSH1B has a 5 A fuse on every output, so a shorted load takes out a 50-cent fuse instead of a $200 relay. That’s the kind of protection that saves a turbine.

GE’s IS230TRLSH1B is the termination assembly for the Mark VIe discrete output modules when driving high-current or inductive loads with the added protection of per-channel fusing. It provides the physical interface between the discrete output module and the field devices—a 37-pin D-sub connector on one side and screw terminals on the other. Like the TRLSH1, the TRLSH1B provides 8 relay outputs, each with a 5 A, 250 VAC/30 VDC contact rating. What it adds is a 5 A fast-acting fuse on each relay contact output, protecting against short-circuit and overload conditions. The B revision also includes a red fuse-blown LED per channel.

Key Technical Specifications

• Relay Outputs: 8 channels, form A (SPST-NO)
• Contact Rating: 5 A at 250 VAC / 30 VDC (resistive load)
• Fusing: 5 A fast-acting, per output (field-replaceable)
• Maximum Switching Power: 1250 VA / 150 W
• Contact Material: Silver alloy (AgNi)
• Relay Coil Voltage: 24 VDC (from the I/O module)
• Response Time: 10 ms (energize), 5 ms (de-energize)
• Mechanical Life: 10 million operations
• Electrical Life: 100,000 operations at rated load
• Fuse-Blown Indicator: Red LED per channel (illuminates when fuse is open)
• Connector Type: 37-pin D-sub (female) for module connection
• Field Wiring: Screw terminals (0.5-2.5 mm² / 20-14 AWG)
• LED Indicators: Green (relay energized); Red (fuse blown) per channel
• Mounting: DIN rail or panel mount
• Operating Temperature: –30 to +65 °C ambient

Quality Inspection Process (SOP Transparency)

This is what every IS230TRLSH1B goes through before it ships:

Incoming Verification: The OEM packing slip is matched against the shipping manifest. Visual inspection includes checking the GE holographic label, verifying the 37-pin D-sub connector is straight and has no bent pins, and examining the screw terminals for any signs of stripped threads or corrosion. We also inspect the relays and fuses—they must be seated correctly and the fuse-blown LEDs must be functional.

Live Functional Test: The TRLSH1B is installed in a test fixture with a Mark VIe PDIOH1B discrete output module. We command each of the 8 outputs from the module and verify the corresponding relay energizes (audible click). The green LED for that channel must illuminate. We measure the contact resistance of each relay’s output at 5 A—must be <0.1 Ω.

For the fuse test, we short-circuit each output (simulating a failed load) and verify the 5 A fuse blows within 1 second. The red LED for that channel must illuminate. We then replace the fuse with a new 5 A fast-acting fuse and verify the relay output returns to normal operation.

For the load test, we connect a resistive load (5 A at 24 VDC) to each channel and cycle the relay at 1 Hz for 100 cycles. We monitor the contact voltage drop at 5 A—must be <0.1 V.

Electrical Parameters: A Fluke 1587 insulation tester measures isolation between the relay contacts and the D-sub connector. We look for >20 MΩ at 500 VDC. We also measure isolation between the relay contacts and the coil (must be >10 MΩ at 500 VDC) and isolation between channels (must be >10 MΩ at 500 VDC). Relay contact resistance is measured with a micro-ohmmeter at 5 A—must be <0.1 Ω.

Mechanical Inspection: Each screw terminal is tested by tightening and loosening it five times to ensure the threads are not stripped. The D-sub connector’s mating surface is inspected for any burrs or damage. The relays are removed and re-inserted to verify the sockets grip properly. The fuse holders are tested by inserting and removing fuses three times to ensure they grip properly.

Final QC & Packaging: The QC report lists the channel verification for all 8 channels, the relay contact resistance measurements, the fuse test results, the load test, the LED functionality, and the isolation measurements. The terminal block goes into a new anti-static bag with a tamper-evident seal, then into a double-walled carton with foam inserts. A “QC Passed” label with the test date and technician’s ID goes on the outer box. All test data and photos are available on request.

Field Replacement Pitfalls

Fused relay terminal blocks are the most robust—and the most complex. Here’s my field-tested list.

Fuse Rating and Substitution
The TRLSH1B uses 5 A fast-acting fuses. If you replace a blown 5 A fuse with a 10 A fuse, the relay contacts won’t be protected—they’ll weld before the fuse blows. I saw a plant where a technician replaced a blown fuse with a 10 A fuse; the next overload welded the relay contacts, and the solenoid stayed energized. The fix was replacing the relay and using the correct 5 A fuse. ❗ Use the correct fuse: 5 A fast-acting, 250 V rating. Don’t substitute. The fuse spec is printed on the terminal block label.

Fuse-Blown LED Interpretation
The red LED on the TRLSH1B illuminates when the fuse is open. But it’s a passive indicator—it draws its power from the load supply. If the load supply is off or low, the LED won’t illuminate even if the fuse is blown. I had a plant where a fuse was blown, but the load supply was turned off, so the LED didn’t illuminate. The technician assumed the output was working and wasted an hour troubleshooting. ❗ The fuse-blown LED only works when the load supply is powered. Always check the load supply before trusting the LED.

Relay and Fuse in Series
The TRLSH1B has the relay contacts and the fuse in series. The fuse protects the relay contacts. If a load short occurs, the fuse blows, and the relay contacts are protected. But if the relay contacts weld first (due to an overload that didn’t blow the fuse—say, a 6 A overload that takes 2 seconds to blow a 5 A fast-acting fuse), the fuse will still blow, but the relay will be welded. I had a plant where a 6 A overload caused the relay contacts to weld after 1.5 seconds; the fuse blew at 2 seconds, but the damage was done. The fix was using a faster-acting fuse (5 A very fast-acting) or a relay with a higher current rating. ❗ The 5 A fuse is fast-acting, but it’s not instantaneous. For critical loads, consider using a very fast-acting fuse (5 A FF) to protect the relay contacts.

Wiring Polarity for DC Loads
The TRLSH1B’s relay contacts are polarity-independent, but the fuse is in the line side. For DC loads, GE recommends wiring the load to the fuse terminal and the return to the common terminal. If you reverse the wiring (load on common, fuse on return), the fuse will still work, but the arc suppression will be less effective. I had a plant where the wiring was reversed, and the contacts arced more than expected, causing early contact wear. The fix was standardizing the wiring. ❗ Wire the load to the fuse terminal and the return to the common terminal. This gives you the best arc suppression.

Fuse Holder Corrosion
The TRLSH1B’s fuse holders are spring contacts. Over time, they can corrode, causing the fuse to have a high-resistance connection. I had a plant where a fuse holder was corroded, causing a 0.5 Ω resistance in the fuse holder. At 5 A, that’s a 2.5 V drop, which was causing the load (a 24 VDC solenoid) to operate at 21.5 V—barely enough. The fix was cleaning the fuse holder. ❗ Keep the fuse holders clean. Use a contact cleaner if you see any discoloration.

Get these five right and you’ll cut rework time by 90%.

New Original vs. Refurbished: Why It Matters

Fused relay terminal blocks are electromechanical devices with critical fusing. Refurbishment risk is significant.

New Original (New Surplus) means this unit came from GE’s production line, sealed in an ESD-safe bag. It has never been wired. The relays are fresh—zero operations, zero contact wear. The fuses are fresh. The sockets and fuse holders are new and tight. The screw terminals have fresh threads. The serial number traces directly to GE’s production database.

Refurbished risk: The relays are the biggest risk. A refurbished TRLSH1B may have relays with thousands of operations already on them. The fuses may have been replaced with non-OEM fuses. The fuse holders may have weakened spring contacts. I saw a refurbished TRLSH1B in a plant where a relay failed in the stuck-on position after 4 months. The refurbished block cost 250; the new surplus unit was 380. The stuck-on solenoid caused a turbine trip, costing $40,000.

Real cost: A failed relay on a critical output can cause a turbine trip or a safety incident. The cost of a trip is tens of thousands of dollars. A new surplus terminal block is cheap insurance.

What we provide: We include a photo of the OEM packing slip with the GE part number and serial number. The anti-static bag is sealed with a tamper-evident label. The QC test report lists the channel verification, the relay contact resistance measurements, the fuse test, the load test, and the isolation measurements. You get a 12-month warranty.

Pricing context: Our price sits 30-50% above refurbished alternatives but 20-40% below GE’s current factory list price.

Performance Benchmarks & Test Results

Measured during our QC test. Conditions: test fixture with a PDIOH1B discrete output module, 24.0 VDC supply (Fluke 8845A), ambient 24 °C.

• Fuse Voltage Drop: At 1 A: 0.02 V. At 5 A: 0.10 V. Within spec.
• Fuse Blow Time: With a 6 A overcurrent, the fuse blew in 1.5 seconds (within spec for fast-acting). With a 10 A overcurrent, the fuse blew in 100 ms.
• Fuse-Blown LED: With a blown fuse and 24 VDC load supply, the red LED illuminated brightly. With 18 VDC supply, it was still visible (dim but functional).
• Relay Contact Resistance: Average across 8 relays: 0.03 Ω at 5 A. Range: 0.02-0.04 Ω.
• Contact Voltage Drop: At 5 A, the voltage drop across the contacts was <0.15 V. Average: 0.12 V.
• Response Time (Energize): 9.5 ms from module command to contact closure. Within the 10 ms spec.
• Response Time (De-energize): 4.5 ms from module command to contact opening. Within the 5 ms spec.
• Isolation (Contacts to Coil): Measured >20 MΩ at 500 VDC.
• Isolation (Contacts to Logic): Measured >20 MΩ at 500 VDC.
• Isolation (Channel to Channel): Measured >20 MΩ at 500 VDC.
• Thread Integrity: All screw terminals were tested with 5 cycles of tightening/loosening. No stripped threads.
• Fuse Holder Integrity: All 8 fuse holders were tested with 5 cycles of fuse insertion/removal. Contacts remained secure.
• MTBF (Published): GE’s datasheet lists 190,000 hours at 40 °C for the TRLSH1B. Based on field data, expect 10-15 years of service under normal conditions (depends on contact switching frequency).

IS200HFPAG CARD-HF AC SUPPLY
IS200HFPAG1A CARD-HF AC SUPPLY
IS200HFPAG2A FAN/XFRMR CARD