vfd - PLC Programming & Automation

PLC Motor Control VFD Setup: DOL, PowerFlex 525, G120

September 13, 2026February 11, 2024 by PLC

Ladder rung: Start in parallel with the Run_Cmd seal-in contact, in series with a normally closed Stop and a Drive_Ready contact, driving the Run_Cmd output

Choose DOL or a drive, wire the stop so it works without the PLC, set the drive parameters and tags, then read the fault codes when it trips.

PLC Energy Management: Metering, Demand and Shedding

September 13, 2026January 21, 2024 by PLC

Ladder rung for load shedding: predicted demand high in parallel with the shed seal-in bit, in series with the shed permit and the chiller alarm contact, driving the shed output for chiller 2

Wire a power meter into Logix or S7, totalize kWh in Structured Text, hold the demand peak with priority load shedding, and check if a VFD retrofit pays.