TECO Electric Motors & Drives: 7 Field Questions (And Answers I Had to Learn the Hard Way)

If you're searching for "teco-electric" or trying to figure out "what size VFD for 5hp motor," you're probably staring at a motor nameplate right now. I've spent ten years on the application side of TECO Electric—sizing motors and drives for B2B customers. In that time, I made at least a dozen mistakes worth roughly $4,000 in wasted hardware. Now I keep a checklist, and this FAQ covers the questions I wish someone had answered before I started.

What size VFD do I need for a 5 HP motor?

Look, the wrong answer is "the same size as the motor"—that's how I bought a 5 HP VFD for a 5 HP motor and watched it trip on start-up for three days. The right way is to check the motor's full-load amp (FLA) on the nameplate, not just the horsepower. A typical 5 HP, 230 V three-phase motor draws about 15.2 A; a 460 V version draws about 7.6 A. Your VFD's rated output current has to meet or exceed that number, ideally with some headroom for overload. As stated in TECO's VFD manuals, size by current, then verify by load. So when someone asks me "what size VFD for 5hp motor?", I answer with another question: "what does the nameplate say?" If the motor is already in hand, the nameplate is your source of truth. If you're between motors, look up the datasheet before you quote a drive.

Is TECO Electric the same as TECO Electric & Machinery?

Honestly, they're the same company. TECO Electric & Machinery Co., Ltd. was founded in Taiwan in 1956, according to their official company history. The brand is commonly shortened to TECO Electric. I've had customers search for "teco-electric" and worry that they're looking at a knock-off when they see the full name. It's the official name—you'll see it on their website, motors, and literature. Interestingly, some catalogs still list the full machinery name, which is why you'll see both forms in search results. So to clear up the confusion: the full legal name and the "teco electric" search phrase refer to the same manufacturer.

Servo motor vs. stepper motor—which should I choose?

This is where I'll probably annoy a few purists: it depends. For a straightforward indexing application with low speed—say 300 rpm—a stepper is fine, reliable, and cheaper. I once second-guessed an engineer on this and specified a servo for a simple pick-and-place job. $800 more than needed. On the other hand, I've also watched a stepper lose steps at high speeds on a 3-axis machine, which meant misaligned parts. Here's the thing: steppers are good at holding torque at standstill, but they lose torque at higher speeds. Servos maintain torque across a wider speed range. At TECO, we look at the duty cycle and the inertia ratio first. If you're still unsure, sketch a speed-vs-torque graph for your load and see where the curve sits. The answer usually becomes obvious.

What does brushless DC motor control actually mean?

Take it from someone who had to explain this to a customer while their production line waited: a brushless DC (BLDC) motor is a three-phase motor with permanent magnets on the rotor, and the "DC" in the name is a little misleading—it needs an electronic controller to convert DC to phase voltages. The controller "commutates" the motor. So you can't just wire a BLDC motor to a battery and expect it to spin. You need a matched drive, and that's where a lot of people stumble. I did this myself in 2019—ordered a nice BLDC motor, missed the controller quote, and had the motor sitting on the bench gathering dust for a month. The same applies to servo drives; they're just a different flavor of the same idea. TECO offers both motors and drives, but the lesson is: plan the whole system before you buy.

Why did my motor and VFD combo trip on startup?

Dodged a bullet on this once. A customer called me at 10 pm because a 7.5 HP machine kept tripping its VFD as soon as it started. I asked for the motor FLA, then the VFD output rating. The VFD was correctly sized, but the acceleration time was set to 1 second for a large flywheel load. We changed it to 8 seconds and it ran smoothly. That's the classic fix. But the other common cause is mistaking HP for actual current draw. A 5 HP motor on a heavy-starting load might need a 7.5 HP VFD just to handle the overload. Also check your wiring: I've seen reversed input phases cause instant trips. TECO's newer drives have auto-tuning that handles part of this, but only if you read the manual. My checklist now: FLA, acceleration time, load type, wiring connections.

What's the #1 mistake people make when picking a motor?

The question everyone asks is "how much horsepower do I need?" The question they should ask is "what's the duty cycle?" A motor rated for S3 duty (intermittent) will cook itself if you run it continuously. I know this because a colleague's project in Q3 2024 ordered a washdown motor for a conveyor that never stopped. It lasted four days. NEMA and IEC define duty types, and TECO's motor data sheets list them clearly. For example, a pump or a fan has an intermittent duty cycle, so it can run hotter than a continuous conveyer motor. Most people oversize the torque, but they undersize the thermal capacity. Check the nameplate's duty rating and the frame thermal rating. Five minutes of verification beats five days of correction—that's the whole game.

Is TECO a reliable brand for industrial automation?

I'm obviously biased—I work with TECO products every day. But I'll give you the honest version: TECO Electric & Machinery has been around since 1956, and their longevity in the global motor market says something. We've had NEMA Premium motors on pumps running 20 hours a day for years. That said, any motor will fail quickly if it's undersized, improperly vented, or driven by a mismatched VFD. In my opinion, "reliability" is as much about the application as the brand. What makes TECO useful to me is how easy it is to find specs and get local support. But your mileage may vary if you're doing extreme-duty work in a dusty environment—then you need to spec enclosure and filtration accordingly. Take the long view: verify your requirements first, then worry about brand.