How to Read a Marathon Industrial Motor Nameplate
How to Read an Industrial Motor Nameplate
Understanding industrial motor nameplate data is essential when selecting motor replacements. The nameplate typically contains most of the key information required to identify a suitable replacement. Being able to interpret the nameplate and understand its abbreviations ensures you choose the right motor for the job.
It's also good practice to record all nameplate details, as this can save time and prevent confusion in the future. Over time, exposure to dirt, rust, and other elements may obscure the nameplate, making it difficult to read when you need it most. Proper documentation now can make replacements much easier later.

- DATE CODE - The month and year manufactured
- MODEL - The ID number
- SER. - Serial number
- PART NO. - Customer part number
- FRAME - The size & mounting
- ENCL - Enclosure (e.g. TEFC)
- PH - Electrical phase usually 1 or 3
- IP - International Protection rating of the enclosure to solids and liquids as defined by IEC 60034-5 and NEMA MG1
- IC - Inherit Cooling
- MTG. - Mountinge
- DES. - Code by NEMA®* or IEC®*
- CODE – NEMA locked-rotor KVA 13. INS CL - Insulation class
- RISE - The temperature rise over ambient expressed in ºC when the motor operates at nameplated HP or KW
- S.F. - Percentage of the rated horsepower the motor can safely operate at Example: 1.15 SF (115% of rated HP)
- MAX AMB - The allowable surrounding air temperature
- ALTITUDE - The allowable altitude
- VOLTS - Voltage rating of the motor at the operating frequency
- HZ - Input frequency of the power supply, usually 50 or 60 HZ
- HP - Rated horsepower the motor will produce
- KW - Rated output in watts
- PF / COS - Power Factor / Cosine is the ratio of actual power to the apparent power
- RPM - Full load speed at rated frequency
- NOM EFF - Average efficiency
- F.L. AMPS - The rated load current expressed in amps at nameplated horsepower with nameplate voltage and frequency
- DUTY - Time rating under load
- TYPE - Electrical type
- SHAFT END BEARING - Manufacturer drive end bearing number
- OPP. END BEARING - Manufacturer opposite drive end bearing number
- MTH/YR MFG. - Month and year the motor was manufactured
- WT/LBS - Motor weight in pounds
- WT/KG - Motor weight in kilograms