Electrical Control & Protection

Combination Starters: Type E, Type F and Fused

A combination starter puts disconnect, short-circuit protection, contactor and overload in one listed unit. How fused, breaker, Type E and F differ.

October 21, 2026

Intrinsic Safety Barriers vs Galvanic Isolators

Zener barriers clamp energy and need a dedicated IS earth; galvanic isolators isolate circuits and do not. How each works and how entity checks work.

October 21, 2026

How to Cross-Reference an Industrial Fuse

A cross-brand fuse must match class, amps, voltage, interrupting rating and time-delay characteristic. How UL classes and IEC categories make it work.

October 19, 2026

Voltage Drop: Formula, Tables and Cable Sizing

Voltage drop = 2 x K x I x L / CM single-phase, 1.732 x K x I x L / CM three-phase. How to apply it, the 3%/5% guide and when to upsize cable.

October 19, 2026

Electrical Noise and EMI in Control Panels

Electrical noise causes random PLC faults and bad analog readings. Where it comes from, how it couples in, and the fixes that actually work.

October 9, 2026

What Is a Line Reactor and When a VFD Needs One

A line reactor is an inductor on the AC input of a drive that smooths current and absorbs spikes. What it does, when a VFD needs one and how to choose it.

October 8, 2026

Ground Fault Protection: GFCI, GFPE and Relays

Ground fault protection detects current leaking to ground. How GFCI, GFPE and ground fault relays differ, how they work and what to check when choosing.

October 8, 2026

Dynamic Braking and Braking Resistors on a VFD

Dynamic braking burns off a motor's regenerated energy as heat in a resistor so a VFD can stop loads fast. How it works, how to size one and common mistakes.

October 8, 2026

What Is an Industrial UPS and When to Use One

An industrial UPS keeps control equipment running through a power loss. The main types, how to size one for a PLC panel and the mistakes to avoid.

October 8, 2026

Multimeter vs Clamp Meter: Which Do You Need?

A multimeter measures voltage, resistance and current inside a circuit; a clamp meter reads current without breaking it. Here is which one fits which job.

October 8, 2026

Insulation Resistance Testing (Megger) Explained

An insulation resistance test applies a DC voltage to check how well wire or winding insulation holds up. How it works, what to record and the safety steps.

October 8, 2026

Pushbuttons, Selector Switches and Pilot Lights

Operator devices on a control panel: how pushbuttons, selector switches and pilot lights differ, how contact blocks work, and what the colours mean.

October 7, 2026

What Is a Surge Protective Device (SPD)?

An SPD diverts voltage spikes away from sensitive equipment. The type 1, 2 and 3 idea, where each goes, what the ratings mean, and why they wear out.

October 7, 2026

Motor Protection Circuit Breakers (MPCB) Explained

An MPCB gives one motor manual switching, overload and short-circuit protection. How it differs from an MCCB and from fuses plus an overload relay.

October 7, 2026

What Is a Disconnect Switch? Fusible vs Non-Fusible

A disconnect switch isolates equipment from its power supply so it can be worked on safely. Fusible vs non-fusible, load-break ratings, and lockout.

October 7, 2026

Buck-Boost Transformers: What They Do and Limits

A buck-boost transformer nudges a supply voltage up or down by a small amount. How it is wired, when it works, and where it falls short.

October 7, 2026

What Is a Transformer? Types and How to Size One

A transformer changes AC voltage from one level to another through magnetic coupling. The main types, what the nameplate means, and how to size one.

October 7, 2026

What Is a Vacuum Circuit Breaker? How VCBs Work

A vacuum circuit breaker interrupts current inside a sealed vacuum interrupter. How it works, where it is used, and what to know when replacing one.

October 1, 2026

Panelboards, Load Centers and Switchgear Compared

Load centers, panelboards, switchboards and switchgear all distribute power but differ in construction and ratings. How to tell them apart and what to check.

October 1, 2026

MCCB Electronic Trip Units: LSI, LSIG and Comms

Electronic trip units let a molded case breaker be tuned for overload, short circuit and ground fault. What L, S, I and G mean and how communications are added.

October 1, 2026

Current Transformers and Transducers: How They Work

Current transformers and transducers measure AC current without breaking the circuit. How they differ, why a CT secondary must not be left open.

October 1, 2026

What Is a Contactor? How It Works and How to Size One

A contactor is an electrically operated switch for heavy loads like motors. How coils, contacts and utilization categories work, and how to size one.

October 1, 2026

What Is a Control Transformer? How to Size One

A control transformer steps line voltage down for control circuits. How VA ratings and inrush work, and why sizing on sealed VA alone fails.

October 1, 2026

Fuse vs Circuit Breaker: How to Choose

Fuses and circuit breakers both protect against overcurrent. How each works, where each wins, and the ratings that matter when you specify or replace one.

October 1, 2026

What Is a Power Distribution Block? Sizing Basics

A power distribution block splits one incoming conductor into several outgoing branches inside a panel. How the types differ and which ratings to check.

October 1, 2026

What Is a Solid State Relay (SSR)? How It Works

A solid state relay switches a load electronically with no moving contacts. How SSRs work, zero-cross vs random turn-on, and when to choose one over a.

October 1, 2026

What Is a Terminal Block? Types and Uses

A terminal block is a modular connector that joins and distributes wires in a control panel. The common types, how to read the ratings, and how to choose.

October 1, 2026

What Is a Wire Ferrule? Types, Sizes and Uses

A wire ferrule is a small sleeve crimped on a stranded conductor so it clamps cleanly in a terminal. How types, sizes and crimp profiles differ, and when to use.

October 1, 2026

What Is a Relay? How It Works and Main Types

A relay uses a small control signal to switch a separate circuit. How the coil and contacts work, the main relay types, and what the ratings mean.

October 1, 2026

What Is a Miniature Circuit Breaker? Curves, Ratings

A miniature circuit breaker protects a circuit from overload and short circuit.

October 1, 2026

Protection Relay Functions Explained: Overcurrent, Earth Fault and ANSI Device Numbers

What protection relays do, what the ANSI device numbers mean, and what to specify when replacing one.

September 21, 2026

RTD vs Thermocouple: Selecting a Temperature Sensor

A technical comparison of RTDs and thermocouples, covering accuracy, range, wiring, and integration with controllers and I/O for reliable industrial temperature.

August 11, 2026

Industrial Lighting: Lumens, CRI and Fixture Ratings

A technical guide to lumens, lux, CRI, and fixture ratings, showing how to select lighting that meets task‑specific illuminance and environmental requirements.

August 11, 2026

Panel Meters, Transmitters and Signal Isolation

A technical guide to panel meter types, signal conditioning, isolation methods, and loop‑powered transmitter wiring for reliable process measurement.

August 11, 2026

Wire Marking and Industrial Labelling Systems

A practical guide to selecting, applying, and documenting wire marking and labeling methods that survive harsh plant environments and meet safety standards.

August 11, 2026

Contactor, Relay, or Motor Starter: What You Actually Need

Understand the critical differences between control relays, contactors, and motor starters, including AC-1 vs AC-3 ratings, coil voltage, and overload.

August 10, 2026

Sizing a Molded Case Circuit Breaker

Selecting a molded case circuit breaker requires separately sizing continuous current and interrupting capacity, then applying derating, coordination, and motor.

August 10, 2026

Why Contactor Contacts Weld Shut

A welded contactor disables the stop circuit, leaving a motor energized after the coil is de-energized.

August 10, 2026

Fuse Classes Explained: CC, J, RK5 and Why It Matters

Fuse classes dictate physical dimensions, interrupting capacity, and let-through energy. Swapping classes can void equipment short-circuit ratings and cause.

August 10, 2026

Overload Relay Trip Classes, and Why Yours Nuisance Trips

Overload relay trip class defines the time to trip at 600% of full-load current.

August 10, 2026

22mm vs 30mm Pilot Devices: Specifying Pushbuttons That Last

22mm IEC and 30mm NEMA panel cutouts are not interchangeable.

August 10, 2026

Push-In vs Screw Terminal Blocks

Screw, spring cage, and push-in terminal blocks differ in vibration resistance, re-torque requirements, and conductor acceptance.

August 10, 2026

How Component Choices Affect Arc Flash Energy

Incident energy scales with fault current and clearing time, making protective device speed the primary lever for reducing arc flash exposure in industrial.

August 10, 2026