Controls Toolbox
Practical calculators, tools and references for the people who wire, program and maintain automated machines. Free, fast and clear about how each answer is worked out.
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Coming soon: Ladder Sim. Practice PLC ladder logic on simulated machines, right in your browser. Learn more
Calculators
- Voltage Drop and Wire Gauge CalculatorCheck a cable run and find the smallest AWG size that works.
- Ohm's Law and AC Power CalculatorSolve V, I, R and P from any two, plus kVA, kW and power factor.
- Motor Full-Load Current CalculatorNEC full-load current table lookup and a current estimate from kW or hp.
- 24 VDC Power Supply Sizing CalculatorAdd up your 24 V loads and pick a power supply with margin for growth.
- Circuit Breaker and Fuse Sizing Calculator (NEC)Size breakers and fuses for motor circuits and continuous loads, with a wire check.
- Available Fault Current Calculator (Transformer)Available fault current at a transformer secondary, for checking interrupting ratings.
- Control Panel Heat and Fan Sizing CalculatorTotal panel heat and the fan airflow needed to keep it within limits.
- 4-20 mA and 0-10 V Scaling CalculatorScale 4-20 mA, 0-10 V and other analog signals to a process value and back.
- PLC Analog Scaling CalculatorScale raw analog counts to engineering units, with gain and offset.
- RTD Resistance to Temperature Calculator (PT100, PT1000)PT100 and PT1000 resistance to temperature, and back.
- Control Valve Cv Sizing CalculatorRequired Cv for a liquid flow, or flow from a known Cv.
- Encoder Counts and Resolution CalculatorCounts per revolution, per inch or millimeter, and count rate.
- Gear Ratio, Torque and Speed CalculatorOutput speed, torque and power through a gearbox.
- Motor Synchronous Speed and Slip CalculatorSynchronous speed, slip and the drive frequency for a target RPM.
- Conveyor Belt Speed CalculatorBelt speed from roller size, motor RPM and gear ratio, or the reverse.
- Air Cylinder Force and Air Consumption CalculatorExtend and retract force and air consumption for a pneumatic cylinder.
- PID Tuning Calculator (Ziegler-Nichols and Lambda)Starting PID values from Ziegler-Nichols, Tyreus-Luyben or lambda tuning.
Tools
- PLC I/O List Builder with CSV ExportTurn a list of I/O modules into a full I/O list with addresses and tags, ready for Excel.
- PLC Tag List Cleaner and Name CheckerClean and check a list of tag names against PLC naming rules.
- Wire Schedule and Wire Label GeneratorNumber your wires and make labels for both ends, then export to Excel.
- Loop Check Sheet Generator (Printable)Make a printable loop check sheet with a row for every I/O point.
- Engineering Unit ConverterPressure, flow, torque, power, speed, temperature and more.
- IPv4 Subnet Calculator for Industrial NetworksNetwork, broadcast and host range, and a same-subnet check.
- PLC Data Converter (Hex, Binary, BCD, Float Registers)Decimal, hex, binary, BCD and floating-point values in two registers.
Reference
- IP Rating Chart (IEC 60529)What each digit of an IP rating means, plus common ratings.
- Thermocouple Color Codes (ANSI and IEC)Wire color codes for types J, K, T, E, N, R, S and B.
- PLC Data Types and RangesSizes and ranges for BOOL, INT, DINT, REAL and related types.
Templates
- Factory Acceptance Test (FAT) ChecklistCheck a panel or machine at the factory before it ships.
- Site Acceptance Test (SAT) ChecklistVerify a control system on site after installation, before handover.
- Pre-Power-Up Checklist for Control PanelsChecks to complete before energizing a panel or machine for the first time.
- Control Panel Preventive Maintenance ChecklistA routine check of an industrial control panel, from filters to backups.
Learn
- VFD Fault Troubleshooting GuideWhat common drive faults mean, the usual causes and what to check first.
- Troubleshooting 4-20 mA and 0-10 V Analog SignalsWhy an analog signal reads zero, sticks, drifts or is noisy, and how to find out.
- Motor Will Not Start: A Troubleshooting GuideWork out why a motor will not start or trips, from the control circuit to the load.
- Industrial Ethernet Troubleshooting GuideA step-by-step approach to Ethernet comms problems between PLCs, drives and HMIs.
- PNP vs NPN Sensors ExplainedSourcing versus sinking, which sensor goes with which PLC input, and how to test one.
- How to Size a Motor Circuit: Fuse, Breaker, Overload and Wire (NEC)The parts of a motor circuit, what sizes each one, and a worked example.
- Fault Current, Interrupting Rating (AIC) and SCCR ExplainedAvailable fault current, AIC and SCCR in plain language, and how to check a panel.
Why use it
Every calculator shows the formula it uses and a worked example, so you can check the answer yourself. Calculations run in your browser and nothing you enter is sent anywhere.