Contactor - PLC Programming & Automation

Functional Safety PLC: Risk Assessment to PLd Architecture

Timing chart of a guard door safety function: the door opens, the safety function result drops shortly after, the contactors release inside the response time budget, and the output only returns after a manual reset pulse with the door closed

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.

Two Motors on One VFD: When It Works and When It Does Not

by PLC

Two motors one VFD: what the drive overload stops protecting, the per-motor device you must fit, why V/Hz only, and the cable length that now adds up.

PLC Safety Interlock: Dual-Channel E-Stop on GuardLogix

by PLC

Timing chart of a dual channel E-stop: channel A opens, channel B follows shortly after inside the discrepancy time, the safety output drops at once, the E-stop is released, and the output only returns after the reset button is pressed and released

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 Inverter Curtailment and Wind Pitch Rate Limits

by PLC

Timing chart of a battery state of charge window: grid charge command stops when state of charge passes 90 percent, charge inhibit latches, and discharge inhibit latches below 15 percent

SunSpec Modbus inverter limits, tracker stow, wind turbine pitch and yaw, a battery SoC window with BMS handshake, and curtailment setpoints over DNP3.

PLC Bit Instructions XIO and XIC ladder examples

by PLC

Explains when to use the XIC and XIO bit instructions for start, stop, and limit switch inputs, with a motor start-stop ladder example.

Star-Delta Motor Starting Mathematical Expansion

by PLC

Why star-delta motor starting cuts inrush current, what it costs in starting torque, and the loads where it will not get the motor moving at all.