Purchase now: Allen Bradley 1746-OBP16 Protected Output Module
Purchase now: Atlantechdrives provides you the 1746-OBP16, an advanced, high-performance 16-channel digital DC output module designed for the Allen Bradley SLC 500 controller system. The «P» in the part number stands for Protected, making this module vastly superior to standard output cards. Engineered to handle extreme industrial environments, the 1746-OBP16 features built-in electronic short-circuit and thermal overload protection on every single channel, completely eliminating the need for replacing blown glass fuses. Furthermore, it boasts an incredible continuous current rating of 2.0 Amps per point (compared to the standard 0.5 Amps), making it the ultimate solution for directly driving high-draw solenoids, heavy-duty contactors, and multiple parallel loads without the need for external interposing relays.
Technical Specifications of the 1746-OBP16
This module utilizes intelligent solid-state circuitry that actively monitors the current flowing through each output. If a field wiring short occurs, the module shuts down the affected channel instantly to protect itself and reports the fault to the PLC processor.
- Part Number: 1746-OBP16
- Module Type: Electronically Protected Digital DC Output
- Compatible System: SLC 500 (1746 Chassis)
- Number of Outputs: 16 Protected Sourcing points
- Operating Voltage: 20.4…26.4V DC
- Continuous Current per Point: 2.0 Amps (High current capacity)
- Protection: Auto-resetting short circuit and thermal overload
- Surge Current: 4.0 A for 10 ms
- Backplane Current Draw: 250 mA at 5V DC
Expert Tips: Maximizing Electronic Protection
The electronic protection on the 1746-OBP16 is a game-changer for plant downtime, but it must be understood correctly. Expert Tip: If a field device shorts out, the specific channel on the OBP16 will automatically turn OFF and its status LED will extinguish. The module is self-protecting. However, it is not auto-restarting while the signal remains High in the logic. To reset the tripped channel, the PLC program must cycle the output instruction (turn the output OFF, then back ON in the ladder logic) after the physical short has been cleared on the factory floor. We recommend programming an automatic reset routine or providing an HMI button for operators to pulse the outputs off/on once maintenance has repaired the crushed cable or burnt solenoid.
Maintenance and Heat Dissipation
Because the 1746-OBP16 can push up to 2.0 Amps per channel (up to a maximum module limit of 8.0 Amps total), it generates significantly more heat than a standard module. When designing your panel, do not place the 1746-OBP16 directly next to a heavy AC output module or the main power supply if possible. Leave a buffer module (like a low-draw input card) next to it to allow the internal heat sinks to breathe properly. Ensure the cabinet’s cooling fans are fully operational, as chronic thermal tripping will eventually degrade the self-resetting silicon components.
Frequently Asked Questions (FAQs)
Q: Does the 1746-OBP16 require external flyback diodes for inductive loads?
A: Unlike standard modules, the 1746-OBP16 actually has built-in surge suppression circuitry that can handle the inductive kickback of most standard solenoids and relays. However, for exceptionally large inductive loads, adding an external diode at the load is still best practice for absolute longevity.
Q: Can I replace a standard OB16 with an OBP16?
A: Yes, it is a direct drop-in replacement in terms of programming and chassis slot compatibility. It is an excellent upgrade for machines that suffer from frequent blown fuses.
Do you need more references from this brand? Explore our full catalog of Allen Bradley here.
For high-current DC applications, this protected output card pairs perfectly with the 1746-P2 modular power supply.
