Technical notes on industrial parts
Field notes on specifying, wiring, and replacing industrial control and switchgear components. Written for maintenance engineers who need to pick a part from a data sheet, not from a brochure - and linked straight to the catalog pages for every component mentioned.
01 Nov 2026 · 5 min read
Reading a circuit breaker trip curve
A trip curve is the only honest document about what a breaker will do. Here is how to read the two axes, what B, C and D actually mean, and why a 16 A breaker trips on a 3 kW motor.
01 Nov 2026 · 5 min read
Contactor coil voltage: 24 V DC or 230 V AC?
The coil voltage on a contactor has nothing to do with the motor it switches. Here is how to pick one that holds reliably, survives long control cables, and matches the PLC output that drives it.
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selection 2circuit-breakers 1protection 1contactors 1control 1Subscribe via RSS · new notes published several times a week.