Allen-Bradley 1769-OW16 Compact I/O 16-Point Relay Output Module

Sixteen relay contacts for mixed AC and DC loads

The Allen-Bradley 1769-OW16 is a 16-point relay output module for 1769 Compact I/O. Each point is a normally open contact, grouped in two groups of eight, and can switch AC loads up to 265V AC or DC loads up to 125V DC. This makes it the usual choice for interposing relays, contactor coils, alarm lamps, horns and small valves on mixed voltages.

Compared with the 16-point solid-state 1769-OB16, the relay module isolates the load completely and handles different voltages in the same group, at the price of slower switching, 10 ms, and a finite contact life.

Technical specifications

Contact ratings

The technical data lists a maximum 2.5 A continuous per point and 20 A per module. The make/break ratings depend on the voltage: at 240V AC the contact makes 7.5 A and breaks 0.75 A, at 120V AC it makes 15 A and breaks 1.5 A, with 1800VA make and 180VA break. For DC the sheet gives 28VA, which means 0.22 A break at 125V DC and 1.2 A at 24V DC.

The minimum load is 10 mA at 5V DC, and the off-state leakage is zero. The sheet recommends surge suppressors across inductive loads to extend relay contact life. Check the load type, since lamp and motor loads draw several times their running current.

Power and bank placement

Because the relay coils are driven from the 24V DC bus, the module draws 205 mA at 5.1V DC and 180 mA at 24V DC, and dissipates up to 4.75 W. Both values should be added to the bank current budget of the power supply. The module is 1.5 slots wide and weighs 450 g.

Dielectric tests of 1836V AC for 1 s apply between output point and bus, and between groups, with 265V AC working voltage for basic insulation. Use the 18-pin terminal block with 22 to 14 AWG solid or 22 to 16 AWG stranded 90 °C copper, and consult the sheet before mixing different voltage classes within one group.

Documents and quotation

The Compact I/O technical data 1769-TD006 contains the relay table and rating chart. For a quotation send the 1769-OW16 reference, series, quantity, the controller or adapter, the load voltages and types. Related hardware is listed in PLC & I/O Cards and 1769-OB16 output module.

How the 1769-OW16 Works

Each of the sixteen outputs on the 1769-OW16 is an electromechanical relay. When the controller sets an output bit, the module energises the relay coil from the 24V DC bus supplied by the Compact I/O power supply, and the normally open contact closes. The contact itself is a dry, potential-free switch: whatever voltage is wired to the group common appears at the output terminal. Because the coil circuit and the load circuit are separated by the relay, the load side is fully isolated from the backplane, and each group of eight can carry a different voltage, for example 230V AC on one group and 24V DC on the other.

The trade-offs come from the mechanics. Switching takes about 10 ms, the contacts wear with every operation, and the life depends heavily on the load current and on whether the load is inductive. For outputs that switch many times a minute, a solid-state module is usually the better choice; for occasional switching of mixed voltages, the relay module is simpler and more flexible.

Selection & Ordering Guide for the 1769-OW16

• 1769-OW16 – 16 normally open relay outputs in two groups of eight.
• 1769-OW16K – conformal-coated version for corrosive or humid atmospheres.
• 1769-OW8 and 1769-OW8I – eight-point relay modules; the OW8I has individually isolated contacts when every output needs its own voltage.
• 1769-OB16 – 24V DC solid-state sourcing outputs for fast or frequent switching.

When you request a quote, include the series letter if a direct like-for-like replacement is needed, together with the controller or adapter and the bank layout. Our team can help confirm the correct ordering code and check whether the 1769-ECR end cap or a replacement terminal block is also required.

Installation & Maintenance

• Mount the 1769-OW16 on DIN rail or panel and slide it along the bus to lock into the neighbouring module; Compact I/O modules are not designed for removal or insertion under power, so isolate the bank before changing a module.
• Add the module’s 5V and 24V current draw to the power-supply budget and keep it within the supply’s distance rating.
• Fit an RC snubber or varistor across AC coils and a flywheel diode across DC coils to reduce contact arcing and extend relay life.
• Do not mix SELV 24V DC circuits and mains-voltage circuits on the same group, and keep the separate supplies clearly labelled in the panel.
• During maintenance, check the output status indicators against the program state and replace the module if a contact is welded or fails to close.

Typical Applications in Oman & the GCC

The 1769-OW16 is used where a CompactLogix or MicroLogix system must drive loads at several voltages: contactor coils for pump and fan starters, 230V AC solenoid valves, beacons and sounders on alarm panels, and interposing relays for motor control centres. It is common in water and wastewater lift stations, building management panels, packaging lines, and utility skids in oil and gas facilities, where a single module can switch both 24V DC field devices and 230V AC auxiliaries.

Why Source from Seven Star LLC

Seven Star LLC is an independent supplier based in Muscat. Seven Star LLC supplies Allen-Bradley Compact I/O modules and related automation hardware across Oman and the GCC. Send the 1769-OW16 catalog number, the quantity and your load details and request a quote; our team can help confirm the correct ordering code.