That 'Bad' Leeson Motor Might Be Fine: What I Learned After 5 Years of Replacing the Wrong Stuff

You Bought a Leeson Motor. Now It Doesn't Work. What Now?

I've been there. You order a Leeson 5 hp motor (or a gear rack, or a linear actuator), it arrives, you get it hooked up, and... nothing. Or it's buzzing. Or moving way too slow. The first few times this happened to me, I panicked. I'd call the supplier, blame the motor, and start the return process. That was before I understood the actual problem.

From the outside, it looks like the equipment is faulty. The reality is that in about 60% of the cases I've dealt with (roughly speaking—don't hold me to that exact number), the issue wasn't the motor. It was something else entirely.

The Surface Problem: 'My Leeson Motor Just Failed'

When I took over purchasing in 2020 for a mid-sized assembly facility, we had a breakdown on a critical conveyor line. The maintenance lead came to me and said, 'The motor is shot. We need a new one now.' We paid for overnight shipping on a replacement—an expensive mistake, as it turned out. The 'dead' motor? It was wired incorrectly for the available voltage.

Most buyers focus on the motor itself and completely miss the supporting components. We tend to think 'part fails → replace part.' But in industrial settings, the part is often the victim, not the culprit.

Deep Dive: The Three Real Reasons Your Leeson Motor Isn't Working

Let's get past the surface. After processing 60-80 orders annually across 8 vendors, I've seen three underlying issues that cause 90% of the 'bad motor' complaints I've handled. These are the things nobody tells you when you start managing maintenance inventory.

1. The Wiring Diagram Was Right, But You Had a Voltage Misconception

This is the big one. People assume that if a motor is labeled '230V', you can just plug it in. I thought that. What I didn't see was that a Leeson 3 phase motor wiring diagram is often a two-part puzzle. Those motors can be wired for low voltage (208-230V) or high voltage (460V). If you wire it for 460V and feed it 230V, it'll run at half speed and overheat. If you wire it for 230V and feed it 460V, you'll get instant tripping (or worse, a fried winding).

The question everyone asks is, 'Does it have the right horsepower?' The question they should ask is, 'Is the motor wiring configured for the available supply voltage?'

2. The 'Leeson Motor 5 HP' Was Correct, But The Application Wasn't

I'll never forget this one. We had a Leeson 5 hp motor that kept tripping the overload relay on a high-inertia fan. The maintenance crew replaced the motor twice—spending about $1,200 each time on units and labor—before I asked the question nobody had thought of: 'Was the original motor matched to the load?'

We found out that the fan had been replaced the year before with a heavier-duty model. The 5 hp motor was never going to handle the startup current. (Note to self: always verify the load BEFORE buying a replacement.) This is a classic overconfidence fail. I knew I should check the specs, but thought 'what are the odds the fan changed?' Well, the odds caught up with me when we ate $2,400 in rejected maintenance costs.

3. The Hidden Culprit: The Drive or Power Supply

A motor isn't a standalone device. It relies on a healthy Variable Frequency Drive (VFD) or a proper power supply. We had a situation where a linear actuator kept failing—three times in one quarter. The vendor was about to give up on us. I finally looked at the disc brake diagram on the replacement unit and realized something was off with the control wiring.

It turned out the VFD's brake resistor had failed, causing excessive DC injection braking. The actuator wasn't failing; it was being destroyed by the drive. **This** is what happens when a linear actuator fails repeatedly—it's almost never the actuator itself.

The Price of Not Digging Deeper

Let's talk numbers. In 2024, our company consolidated procurement across three locations for about 400 employees. I analyzed our 'motor failure' data from the previous year:

• Direct replacement cost: $4,500 in new motors and actuators
• Downtime cost (estimated): Closer to $15,000 in lost production
• Reputation cost: The maintenance team lost trust in me and started going around purchasing to buy parts from other suppliers. That cost us vendor leverage and created a huge mess.

The worst part? We only needed to replace about 30% of those components. The rest could have been fixed with a wiring correction, a VFD parameter change, or a simple drive diagnostic.

The Short Solution: A Smarter First Step

So what do I do now? It's pretty simple.

Before you buy another Leeson motor or a replacement linear actuator, do this:

1. Check the wiring diagram. Seriously. I've started making it a rule. Pull up the Leeson 3 phase motor wiring diagram from their catalog. Verify the motor plate matches the supply voltage.
2. Test the drive or power source. A simple voltage check at the motor terminals can tell you if the drive is delivering the right signal.
3. Ask 'what else failed recently?' If you just replaced a gear rack and now the actuator is acting up, the issues might be linked.

This process isn't revolutionary. It's just the opposite of panicking and buying a new part. It's saved us thousands, but more importantly, it's made my internal customers trust my decisions again.

Small tip: when I was starting out, the vendors who treated my small orders (a single $200 Leeson motor) with respect, and didn't just push a quick sale, are the ones I still use for $20,000 orders. A good supplier will help you troubleshoot, not just upsell.