1756-OW16I New Original 1756OW16I Digital Relay Module
PRODUCT DETAILS
1756-OW16I — 1756 16-Point Individually Isolated Relay Output Module
The 1756-OW16I is a 16-point relay output module for the 1756 chassis with each contact individually isolated — no shared common between any of the sixteen points or the backplane. Each Form A (normally open) contact switches its own circuit independently, at its own voltage, referenced to its own supply. This is a meaningfully different architecture from group-common relay modules, and it earns its place specifically where field circuits can't share a reference.
Specifications
| Parameter | Value |
|---|---|
| Part Number | 1756-OW16I |
| Output Points | 16 |
| Contact Type | Form A (Normally Open), individually isolated |
| Rated Voltage (AC) | 240V AC max per point |
| Rated Voltage (DC) | 125V DC max per point |
| Rated Current | 1 A per point (resistive) |
| Isolation | Point-to-point and point-to-backplane |
| Electrical Life (full load) | 100,000 operations |
| Mechanical Life | 10 million operations |
| RTB | 1756-TBCH or 1756-TBS6H (36-pin) |
| Operating Temperature | 0°C to 60°C |
Wiring and Load Notes
- Each output has its own dedicated pair of terminals — no shared common bus to land, but correspondingly more individual wiring runs to manage on the RTB.
- For inductive loads, fit a suppressor at each load individually — an MOV/RC snubber for AC, a flyback diode for DC — since there's no shared protection scheme across points the way there might be on a group-common design.
- External fusing per circuit is still required; the module's isolation doesn't include branch circuit protection.
- Document which voltage and supply feeds each point during commissioning — with full isolation, there's no visual grouping cue on the terminal block to remind a technician later which circuits are AC versus DC.
FAQ
Q: Why is the per-point current rating lower than a standard group-common relay module?
Achieving full individual isolation on sixteen points within a single module requires more internal circuitry per channel, which trades off against current capacity compared to simpler shared-common designs. For higher per-point current with isolation, fewer-channel isolated modules with higher individual ratings are available instead.
Q: Can all sixteen outputs run from completely different AC phases simultaneously?
Yes. Since each point is fully isolated from the others, there's no requirement for phase or reference consistency across outputs — each can connect to an entirely independent circuit.
Q: Does isolation affect the module's response time or switching speed?
No. Isolation is an electrical architecture feature affecting noise immunity and circuit independence — it doesn't change the relay's mechanical switching speed, which remains consistent with standard electromechanical relay behavior.
Q: What RTB is compatible with this module?
The standard 36-pin RTB options — 1756-TBCH (cage-clamp) or 1756-TBS6H (screw clamp) — both work, ordered separately from the module itself.