How to read a nameplate and find the part number
A nameplate often lists five or more numbers. Searching the wrong one wastes time. Here's how to pick the right one.
The numbers you'll usually see
- Catalog or model number (often "Cat. No.", "Model", "Type" or "P/N"). This is the one to search.
- Serial number ("S/N"). Unique to that one unit — useful for warranty, not for buying.
- Series or revision letter ("Ser. B", "Rev. C"). Keep it with the catalog number; it can change firmware or fit.
- Date code. Tells you when it was built.
- Ratings — voltage, amps, horsepower, frequency. Useful for checking a replacement.
Tips for searching
- Type the number exactly, including dashes and suffixes.
- Add the brand — many makers reuse similar numbers.
- Watch for look-alike characters: 0 and O, 1 and I, 5 and S, 8 and B.
If the label is worn or missing
Check for a second label inside the cover or on the side. Look up the machine's manual or wiring diagram, which usually lists the part. Measure dimensions and write down the ratings and terminal layout so you can match a replacement.
Search from a photo
With Part Finder you can upload a photo of the label. It reads the part number and brand for you, then searches vendor sites for it.