Overload Relays: Thermal vs Electronic and Trip Classes 10, 20, 30
How thermal and electronic overload relays protect motors, what trip classes 10, 20 and 30 mean, and how to set and reset a relay correctly.
Contactors
Contactor Coil Voltages and Coil Codes: How to Get the Right One
How contactor coils differ (AC or DC, 50 or 60 Hz, electronic) and how to read coil markings and codes so the replacement closes reliably.
Buying Used and Legacy Industrial Parts: A Practical Checklist
A practical checklist for buying used and legacy industrial parts: part number and series, coil voltage, firmware, photos, condition notes, warranty, lead time and cross-border shipping.
Contactor Ratings: IEC Utilization Categories by Type of Application
What IEC utilization categories such as AC-1, AC-3, AC-4, AC-15 and DC-13 mean, with tables of typical applications and tips for comparing contactor ratings.
Contactor Applications: How Contactors Work and How to Select One
How contactors work, what AC-3, AC-1 and AC-4 ratings mean, and a step-by-step method to select or replace a contactor, including reversing pairs and interlocks.
Short-Circuit Current Ratings (SCCR)
What a short-circuit current rating is, how it differs from interrupting rating, and why one low-rated component can limit the SCCR of a whole control panel.
North American Standards and Certifications
How North American electrical standards are organized (NEC, CEC, UL 508A, UL and CSA product standards) and how to read UL, cULus and CSA marks on...
Motor Rated Current by Power in kW (IEC 60947-4-1 Table)
How to read a kW-to-current table for IEC motors, use the nameplate correctly and convert kilowatts to horsepower.
