How to Choose a Motor Protection Relay
A practical guide to matching motor protection functions with the motor, load and operating environment.
Practical field reference
Understand industrial electrical systems before you change a setting.
Original guides for engineers, technicians and maintenance teams working with motor protection, multifunction meters, switchgear climate control and industrial measurements.
Browse the guidesStart with a real maintenance question
Each guide explains the reasoning, records to collect and limits of the advice. The examples are educational and should be checked against the equipment documentation and site safety rules.
Three-Phase Current and Voltage Basics for Maintenance Teams
Understand line and phase values before reading a power meter or investigating an unbalanced load.
How to Read a Multifunction Power Meter
A field checklist for voltage, current, power factor, energy and alarm readings.
How to Prevent Condensation in Electrical Cabinets
Why moisture forms inside switchgear and how inspection teams can reduce the risk.
Common Causes of Motor Overheating
A structured way to separate electrical, mechanical and environmental causes before changing settings.
CT Ratio Selection Guide for Power Measurement
How to think about current transformer ratio, accuracy and measurement range.
Temperature and Humidity Control for Switchgear
A practical monitoring plan for cabinets exposed to weather, shutdowns and changing loads.
Why a Motor Trips During Startup
How to distinguish normal starting current from a real starting problem.
Wireless Temperature Monitoring in Electrical Systems
What to define before using wireless sensors on busbars, terminals or cabinets.
Electrical Cabinet Inspection Checklist
A repeatable checklist for enclosure condition, environment, measurement and records.
Built around practical experience
Mairun manufactures and supplies industrial electrical instruments and protection equipment. This knowledge hub shares general engineering explanations; product selection and site commissioning should be confirmed by qualified professionals.