Replacement
IEC drop-in replacement check
A drop-in is a judgement on the nameplate and the shaft, not on the logo (Siemens, ABB, WEG, JW). Same shaft height can still be the wrong shaft diameter, flange instead of feet, or a different pole count. Work through the checks. All yes → a general-purpose YE3 is the usual quote. Any no → send photos; it may still be custom, not a silent swap.
About this tool
A drop-in is a judgement on the nameplate and the shaft, not on the logo (Siemens, ABB, WEG, JW). Same shaft height can still be the wrong shaft diameter, flange instead of feet, or a different pole count. Work through the checks. All yes → a general-purpose YE3 is the usual quote. Any no → send photos; it may still be custom, not a silent swap.
Who this is for
Use it when replacing an installed IEC motor and you need a straight answer before you enquire.
Calculator
What must match
- Drop-in
- The new motor sits on the same feet or flange, the coupling or pulley fits the same shaft, and the speed/kW match the driven machine. The logo on the old plate is irrelevant.
- Frame vs shaft
- Same H (frame number) can still be a different D (shaft diameter) between makers or between a brake motor and a standard TEFC.
- Poles
- A 2-pole “same kW” motor will run at roughly twice the speed of a 4-pole. That is not a drop-in on a pump or fan.
Check list (same as the boxes above)
| Item | Unit / code | Why it matters |
|---|---|---|
| Shaft height H | mm = IEC frame number | Foot-mounted machines will sit high or low if H differs |
| Shaft diameter D and key | mm | Coupling or pulley bore. Wrong D is not a drop-in |
| Mounting | B3 / B5 / B35 / V1 | Flange diameter and spigot must match the driven machine |
| Output | kW or hp × 0.746 | Undersize burns out; oversize may still be acceptable if speed matches |
| Poles / r/min | 2/4/6/8 or r/min | Sets pump/fan duty. Match frequency (50 vs 60 Hz) as well |
| Voltage & Hz | V, Hz | Wrong winding will not start correctly or will overheat |
| Specials | brake, gear, Ex, VFD-only | YE3 general-purpose is the wrong family — send photos |
Need a JW motor?
Send kW or hp, volts, frequency, poles, mounting, and a nameplate photo. Stock IEC three-phase (YE3 / Y2) or custom windings — we quote from the plate, not from the logo.
Contact JWMotor