K1 is a 110 V AC contactor on a saw, its coil is switched by a solid-state relay, the SSR is driven from output pair 0 of a 1791ES-IB8XOBV4, and every 600 ms the contactor makes a small tick you can hear from the door of the panel. The scope on O0+ shows why: the … Read more
The guard on the case packer closed at 14:07 and the infeed conveyor started on its own, with the blue reset button 4 m away and nobody within reach of it. The DCS instruction on that gate was configured Restart Type Manual, exactly as the drawing said, and the machine still restarted, because the button … Read more
K1 and K2 are 100S-C09 safety contactors in series on a 4 kW conveyor motor, the CROUT that drives them holds Fault Code 16#5003 – both feedbacks ON with the outputs off – through every press of the reset button, and the suggestion at 06:10 was to raise the Feedback Reaction Time from 100 ms … Read more
The 440R safety relay on the new guard, a 440R-S12R2, was showing PWR/Fault flashing red four times, IN steady red with the door shut, and the electrician had already swapped it for the spare, which did the same thing within a second of power-up. The guard switch is a single-contact tongue switch, and the link … Read more
The guard on the case packer came off its 440R-S12R2 on a Saturday and went onto a 1791ES-IB8XOBV4 under a GuardLogix 5580, same tongue switch, same two 100S-C09 contactors, and the first time the door was closed the DCS instruction reported Fault Code 16#4000 and would not take a reset. Channel A active, channel B … Read more
How functional safety works on a PLC job: the ISO 13849-1 risk graph, PLr, category 3 architecture, MTTFd, DC, CCF, a PFHd budget and SISTEMA.
P033 [Motor OL Current] on a PowerFlex 525 holds exactly one number. Land two 3 HP motors on T1, T2 and T3 and that number is now watching the pair as though they were one 6 HP machine, which leaves neither motor protected. That single parameter is the whole argument. Two standard induction motors will … Read more
When a standard interlock is not enough, how to wire and configure a dual-channel E-stop on GuardLogix safety I/O, and the reset rule nobody may break.
SunSpec Modbus inverter limits, tracker stow, wind turbine pitch and yaw, a battery SoC window with BMS handshake, and curtailment setpoints over DNP3.
XIC and XIO instructions are one of the most used basic instructions in plc ladder programming. It is in the category of bit instruction and bit instructions can be used in input and output tags. If you have a digital input, we can define and use these inputs in the PLC using the XIC instruction … Read more
Motor Starting Ways Asynchronous motors draw up to 3-4 times their nominal current at the time of the first start. Although these values do not have much effect on the electrical installation in small motors, they can cause some negative situations in large powerful motors. When a large powerful asynchronous motor draws 3-4 times the … Read more