The PLC SLC 500 1746-OBP16 module is an output module with fuse protection. The fuse on the module provides short circuit protection for wiring with 16 AWG or higher-gauge wires to external loads. If a short circuit occurs on an output channel and it damages the channel transistor, then either the module will need replacement or the load will need to be moved to a spare channel on the module. The fuse on the 1746-OBP16 module does not provide overload protection. User-supplied fuses should be used to provided overload protection on the output channels. For overload protection, PLC recommends the use of external fuses which are matched to the load. If a fuse blows on the module, then the LED indicator provided for the indication of a blown fuse will light up as long as the module is connected to the backplane power.
All of the outputs on the 1746-OBP16 module are deactivated if the fuse blows. The processor continues with the module outputs deactivated if JP1 is set to “Processor Continues” and all processor operations cease with the outputs deactivated if JP1 is set to “Processor Faults”. There are 16 output channels on the 1746-OBP16 module which support 20.4 to 26.4 Volts DC operating range. At 5 Volts DC, the module draws 0.25 Amps from the backplane. The continuous current per point is 1.5 Amps at 86 degrees Fahrenheit and 1 Amp at 140 degrees Fahrenheit. The on-state maximum voltage drop is 1 Volt at 1 Amp. The rated surge current per output point is 4 Amps for 10 milliseconds and the rated surge current per module is 32 Amps for 10 milliseconds.
