Omron CJ1W-OC211 CJ-Series 16-Point Relay Output Unit

Overview

The Omron CJ1W-OC211 is a 16-point relay contact output unit for Omron CJ-series and NJ-series controllers. It takes the results of output instructions from the CPU Unit and switches external loads through sixteen relay contacts sharing one common, each rated 2 A at 250 V AC or 24 V DC with a unit total of 8 A. Because the outputs are dry relay contacts rather than transistors, one unit can drive AC contactor coils, DC solenoid valves, indicator lamps and interposing relays from the same card.

Relay output cards are the workhorse of motor control and valve sequencing panels built on Omron PLCs, and they are also the units that wear out first in high-cycling duty. Seven Star LLC supplies the Omron CJ1W-OC211 to panel builders and maintenance departments in Oman and the GCC, with engineering support in Muscat for replacing a failed output card on a pumping station or process skid.

Operating Principle

When the CPU sets an output bit, the Omron CJ1W-OC211 energises the coil of the corresponding on-board relay, closing its contact between the output terminal and the common. The relays are type NY-24W-K-IE from Fujitsu Takamizawa Components and are not user-replaceable. Coil power comes from the CJ internal supply: the unit consumes 110 mA maximum at 5 V DC plus 6 mA per ON point at 24 V DC, up to 96 mA with all sixteen outputs energised. ON and OFF response times are each 15 ms maximum, which is fast enough for motor starters, valves and alarms but not for pulse-train or high-speed counting outputs, where a transistor unit is the right choice.

Contact life of the Omron CJ1W-OC211 depends directly on the load. Omron rates electrical life at 150,000 operations for a 24 V DC resistive load and 100,000 operations for a 250 V AC inductive load with power factor 0.4, against a mechanical life of 20,000,000 operations. Minimum switching capacity is 1 mA at 5 V DC, so the contacts can also pass low-level signals to other controllers. The practical consequence is galvanic separation between PLC logic and field power, with 20 MΩ insulation (500 V DC) and 2,000 V AC dielectric strength between the external terminals and the GR terminal.

Engineering Design of the Omron CJ1W-OC211

The Omron CJ1W-OC211 is a single-width CJ basic I/O unit that occupies one output word. Its front panel carries sixteen output indicators numbered 0 to 15 and a removable 18-point screw terminal block covered by a transparent hinged lid; terminals A0 to A7 and B0 to B7 carry the outputs and A8/B8 are the common. The unit is marked AC250V 2A / DC24V 2A on the front label, and it weighs 170 g maximum, heavier than DC input cards because of the sixteen relays inside.

Up to ten Omron CJ1W-OC211 or other basic output units of this group can be mounted on each NJ or CJ CPU rack and on each expansion rack, according to the Omron mountable-racks table. Because all sixteen contacts share one common, mixed voltages cannot be switched on the same card; where 24 V DC solenoids and 230 V AC contactor coils must be kept apart, Omron offers the CJ1W-OC201 with eight independent contacts. Good practice for inductive AC loads is a surge suppressor across the coil, and for DC loads a flywheel diode, to extend relay life.

Key Features

The Omron CJ1W-OC211 brings these output functions to a CJ-series or NJ-series rack:

• Sixteen relay contact outputs on one common, switching up to 2 A at 250 V AC or 24 V DC per point.
• Unit current limit of 8 A, suitable for contactor coils, solenoid valves, horns and pilot lamps.
• Minimum switching capacity of 1 mA at 5 V DC for low-level signal interfacing.
• Electrical relay life of 150,000 operations at 24 V DC resistive and 100,000 operations at 250 V AC inductive.
• Mechanical relay life of 20,000,000 operations.
• ON and OFF response time of 15 ms maximum each.
• Removable 18-point terminal block that allows unit exchange with wiring left in place.
• 2,000 V AC dielectric strength between external terminals and GR for robust separation of field and logic circuits.

Industrial Applications

Typical uses of the Omron CJ1W-OC211 include start and stop commands to motor contactors in pump and fan panels, opening and closing of solenoid valves on filtration and chemical dosing skids, energising beacons and sounders such as the Schneider Electric Harmony XVB signal tower, and driving coils of contactors like the Schneider Electric TeSys D LC1D contactor in motor control centres. In RO desalination plants, district cooling stations and wastewater lifting stations across Oman, one CJ rack commonly combines DC input cards for feedback with relay output cards for commands.

Since relay contacts wear with every switching cycle, operators in the Sohar and Salalah industrial zones usually hold a spare Omron CJ1W-OC211 for each critical panel. Seven Star LLC supplies the unit as a trusted supplier together with the companion

Omron CJ1W-ID211 16-point DC input unit

Technical Specifications

The Omron CJ1W-OC211 data below come from the Omron CJ-series Output Units datasheet (CJ1W-OC/OA/OD).

How to Order

For the Omron CJ1W-OC211, send Seven Star LLC an RFQ with the quantity, your CPU model and the loads being switched. Our automation engineers in Muscat will confirm availability and lead time, review rack power and suppression requirements on request, and provide the Omron CJ-series Output Units datasheet for download. Seven Star LLC supplies Omron automation components throughout Oman and the GCC with engineering support in Muscat.