GE IC694MDL940 16-Point Isolated Relay Output (Form A)

Description

In many industrial automation environments the final control element isn’t a 24 VDC solenoid or a 4–20 mA valve — it’s a 120 VAC coil, a 230 VAC motor starter, a pilot light on a legacy control desk, or a 60 VDC brake coil. When you need to switch real-world AC and DC loads directly from the PLC without adding rows of ice-cube relays, external snubbers, or interposing panels, the cleanest and most bulletproof solution has always been a high-quality relay output module. The problem with most “standard” relay cards is either low contact rating (1–2 A), shared commons that create sneak paths, or mechanical life that collapses after a few hundred thousand cycles of inductive loads.

This is precisely where the GE IC694MDL940 earns its keep. This 16-point Form A (SPST-NO) relay output module for the Rx3i PACSystems platform delivers individually isolated, dry contacts rated for 2 A continuous at 24 VDC or 120/240 VAC — with a full 10 A inrush capability and mechanical life exceeding 10 million operations. Every single output is brought out to its own pair of terminals with no shared commons, so you can freely mix 24 VDC solenoids, 120 VAC pilot devices, 230 VAC contactors, and even low-voltage DC loads on the same module without worrying about voltage differences or backfeed paths. For plants migrating from Series 90-30, upgrading remote I/O drops, or building new Rx3i-based machines that must interface to decades-old field devices, the GE IC694MDL940 is the universal relay output workhorse that simply refuses to become the weak link.

The GE IC694MDL940 occupies one slot on any Rx3i universal backplane and appears as sixteen %Q bits to the programmer. Each relay is driven by an optically isolated driver with built-in coil suppression, and status LEDs show coil energization (not contact state — a deliberate choice that prevents false confidence from welded contacts). Field power is supplied by the user — there is no internal 24 V supply — so the module draws only 6 mA per active point from the 5 V backplane regardless of load voltage. Contacts are bifurcated silver alloy for low contact resistance and high reliability even with very low-level signals (5 V/10 mA minimum recommended).

Diagnostics include individual blown-fuse detection when external fusing is added, and the module supports hot insertion without disturbing field wiring. Because Rx3i backplanes allow mixing high-density and standard modules freely, the IC694MDL940 fits seamlessly alongside 32-point discrete cards, analog modules, or high-speed counters.

Choosing the GE IC694MDL940 means you can finally eliminate entire interposing relay panels. The 2 A resistive / 10 A inrush rating drives virtually any pilot device found in industry — from 120 VAC Allen-Bradley 100-C contactors to 24 VDC Festo valve manifolds — without external snubbers or MOVs in most cases. Because every contact is truly isolated (1500 V isolation point-to-point and point-to-backplane), you can safely mix line-voltage and low-voltage loads on the same card. Maintenance teams love the removable terminal blocks and the fact that a single welded contact never affects the other fifteen outputs.

Over thousands of installations the IC694MDL940 routinely achieves 15–20 years of service with zero relay failures when applied within rating, making it one of the lowest lifetime-cost output modules in the Rx3i family.

You’ll find the GE IC694MDL940 switching motor starters in water/wastewater lift stations, energizing tower lights on automotive assembly gantries, actuating 230 VAC hydraulic valves on presses, and driving 125 VDC brake coils on overhead cranes. Food & beverage plants use it to fire 120 VAC glue guns and heat-seal elements. Utilities rely on it for breaker trip/close coils in substation Rx3i remote racks. In every case the requirement is rock-solid isolation, universal voltage capability, and contacts that simply do not wear out — exactly what the IC694MDL940 has delivered since the Rx3i launch.

IC694MDL930 – 8-point isolated 4 A relay version (higher current)

IC694MDL916 – 16-point relay with selectable NO/NC contacts

IC694MDL931 – 8-point isolated relay, 120 VAC only

IC694MDL645 – 16-point 24 VDC input companion

IC694MDL742 – 16-point 24 VDC 0.75 A transistor output (faster)

IC694MDL940A – Earlier revision (functionally identical)

IC694TBB032 – Extended-depth terminal block for high-density wiring

IC694ACC300 – Replacement terminal blocks (pair)

Before installing the GE IC694MDL940, calculate total inrush — sixteen 10 A contactors starting simultaneously can momentarily pull 160 A — so size your field supply and wiring accordingly. Use appropriately rated suppression (MOV for AC, flyback diode for DC) on highly inductive loads to maximize contact life. Torque terminals to 0.5–0.6 Nm and consider adding external fuse blocks if you need blown-fuse diagnostics. Keep one spare set of terminal blocks on the shelf — they make emergency rewiring painless.

In service, maintenance is visual: cycle the outputs annually while listening for sluggish relays (rare) and check contact resistance on high-cycle points every few years. The relays themselves are not field-replaceable, but the entire module swaps in seconds via hot-insert.