I'm the office administrator for a 120-person engineering firm. I manage maintenance and facilities purchasing, roughly $250,000 a year across eight vendors, and I report to both operations and finance. So when a motor goes out, I'm the person who has to get the replacement ordered—without being an electrical engineer.
Motor orders used to make me nervous. Then, in March 2023, a replacement motor came back with the right frame, the right horsepower, and the wrong brake. That one miss cost us $1,800 in expedited shipping and a week of downtime. It was the reminder I needed: ordering a LEESON motor isn't about knowing motor theory. It's about collecting the right details before you call anyone.
This checklist is for anyone who suddenly has to source a motor without a specialist on their team. It has five steps. If you can follow a grocery list, you can follow this.
Why Motor Orders Go Wrong
Most motor replacement mistakes aren't because someone picked the wrong brand. They happen because the request was incomplete. LEESON makes a broad lineup—AC induction motors, LEESON DC permanent magnet motors, gear motors, servo motors, and stepper motors. Saying 'I need a 1 horsepower LEESON motor' is not enough. A 1 HP motor can come in different frames, voltages, speeds, enclosure types, and duty ratings. The nameplate is the source of truth.
The 5-Step Checklist
Step 1: Photograph the LEESON Motor Nameplate
The single most useful thing is a LEESON motor nameplate. If you are standing in front of the motor, take a well-lit photo with your phone. Do not rely on memory. One maintenance team I worked with tried to order from memory, and it ended with a return.
On a standard LEESON motor nameplate, you'll usually find the model number, frame size, horsepower, RPM, voltage, full-load amps, service factor, duty rating, enclosure type, and sometimes brake information. If the plate is worn or missing, look for an old purchase order or ask the machine manufacturer for the bill of materials. Guessing is how the wrong motor ends up at your loading dock.
Checkpoint: You can read every line of the nameplate in your photo.
Step 2: Identify the Motor Type
This step sounds obvious, but it still catches people. LEESON makes different motor families, and each has different selection rules. Here are the ones that show up in my purchase requests:
- AC induction motor: the everyday motor for pumps, fans, conveyors, and other fixed-speed or lightly controlled applications.
- LEESON DC permanent magnet motor: a DC motor with permanent magnets in the stator, commonly used with variable-speed drives. If the nameplate says 90 VDC or 180 VDC, you are in this group.
- Stepper motor: the answer to 'What's a stepper motor?' is basically a brushless DC motor that moves in fixed increments. It is designed for positioning and controlled motion, not for continuous high-speed use.
- NEMA 17 stepper motor: NEMA 17 is a frame size defined by the NEMA standard, roughly 1.7 inches square, not a voltage or torque number. It is common in 3D printers, CNC routers, and lab equipment.
- Gear motor: a motor paired with a gearbox to deliver lower speed and higher torque.
If you are replacing an existing motor, match the type that is already there. This is not the time to upgrade to a NEMA 17 stepper motor unless a qualified engineer has confirmed it works with your machine. I'm not 100% sure of the engineering details on every application, but I know enough to say: don't substitute motor types casually.
Checkpoint: You know which motor family you're replacing and can write it in one sentence.
Step 3: Check Frame, Mounting, Shaft, and Rotation
Here is the step I had no idea about before 2023. A motor can have the right horsepower and still be completely wrong because of the frame. Frame sizes, like 56C, 143T, or 182TC, are standardized under NEMA MG 1, but you still have to verify the mounting style: foot mount, C-face, or D-flange. You also need shaft diameter, shaft length, keyway size, and rotation direction.
The detail that people often overlook is the keyway. A keyway that is off by even a small amount can cause vibration when you connect the coupling. I'm not saying every motor order requires a micrometer. I'm saying take a photo of the shaft and the existing coupling before you remove the motor. Put the photo in the same email as the nameplate photo.
Checkpoint: Frame, mounting, shaft, keyway, and rotation are all in your notes or photos.
Step 4: Verify Voltage, Phase, Amps, and Brake Options
Now we get into the parts that determine whether the motor actually runs. For an AC motor, you need voltage (for example, 230/460 V), phase (single or three), frequency, full-load RPM, and full-load amps. For a LEESON DC permanent magnet motor, you also need armature voltage and the DC control type it connects to. Getting this wrong can damage the motor or the drive. If the motor will run from a variable frequency drive, tell the supplier that too.
Also, this is the step where I failed in 2023: mechanical disc brakes. Some LEESON motors include a mechanical disc brake mounted on the non-drive end. It is fail-safe—when power is removed, spring force applies the brake and holds the load. If you order a replacement without the brake, the machine could coast or drop when it stops. That is not just a performance issue. It is a safety issue.
If the nameplate or the original PO includes a brake, match the brake voltage and torque rating. Don't assume all brakes are the same. In many cases, the brake is listed separately or in the model number. When in doubt, include 'brake' in the description you send to the supplier. It costs nothing to verify, and it saves you from my March 2023 experience.
Checkpoint: Voltage, phase, amps, and brake details are collected. If a brake is present, brake voltage and torque are verified.
Step 5: Ask the Supplier What They Need to Verify
With the nameplate and mechanical details in hand, you are ready to talk to a distributor or an industrial supplier. Here is where my opinion comes in: a good supplier will tell you what they don't know. This is actually the part I trust more than low prices.
In 2024, I compared quotes from two suppliers for the same motor. One said, 'We can do that,' and sent a quote. The other said, 'Let me check compatibility with your control before I quote.' The second supplier got the order, even though their price was 4% higher. The fastest quote is not always the most useful one.
To be fair, some buyers just want a part number and a price. But for motors, the cost of being wrong is usually way more than the price difference. A supplier who recommends a specialist for unfamiliar applications is a supplier I trust. I once asked a supplier about a positioning application, and they said, 'This isn't really our strength—you should talk to a motion-control specialist.' That honesty made me want to work with them again. I'd rather work with someone who knows their boundary than a generalist who overpromises. That matters especially when you're dealing with stepper motors or DC applications, where the control system is part of the equation.
Checkpoint: The supplier confirmed compatibility rather than just sending a quote.
Common Mistakes to Avoid
- Ordering from memory. Older machines often have replacement motors that don't match the original bill of materials. Take a current photo instead.
- Ignoring the brake. A mechanical disc brake is a safety component, not an extra. If it's specified, match it.
- Forgetting the control. A LEESON DC permanent magnet motor only works if its voltage and control match the drive.
- Assuming the frame size is optional. The frame determines whether the motor physically mounts to the machine. It is not a minor detail.
- Not asking about duty. Continuous-duty and intermittent-duty motors are not interchangeable in every application.
Bottom Line
The best time to understand what a replacement LEESON motor needs is before you call the supplier, not after the wrong motor shows up. Take the photo, copy the nameplate numbers, and ask the questions above. It feels like a lot the first time, but it quickly becomes routine.
And if you don't know whether you need a standard AC motor, a LEESON DC permanent magnet motor, or a NEMA 17 stepper motor, that's okay. Ask for help—but ask someone who tells you exactly what they can and can't do. There's something satisfying about a replacement motor that arrives, mounts, and runs the first time. Most of that satisfaction comes from doing the boring checklist work before anyone gets involved.
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