Teco - JNEV-203-H1 Variable Frequency Drive (Rating: 5)

Now that I have been using this VFD for a few weeks I thought it might be time to post a review of it.

The sole reason for purchasing this product was to power the 3 phase motor on my Unisaw given that I only have single phase power at my location. I looked at alternatives like a Rotary Phase Converter, a Static Phase Converter or even swapping out the 3 phase motor for a single phase motor but I wanted to experience the full power this motor offered. So, in the end I opted for the VFD and in particular the JNEV-203-H1. I selected this model on the advice of the knowledgeable folks over at Practical Machinist. In short, the EV models offer 3 wire controls natively while other Teco models require some compromise to do that. The cost was $215 from dealerselectric.

Prior to purchasing this product I did a fair amount of research because it seemed most folks were a little intimidated if not frightened about the prospect of running their equipment off these devices. Also, many were confused about the wiring and settings on their VFD's. I'm sure I would have been too if I had not read about the mistakes and successes of others and took the time to understand the manual before even thinking about setting it up. Just verify that you have a VFD that is rated for the motor's HP. Mine is 3 HP so I got the 203 which is rated for 3 HP.

Set up was really quite painless. I did a quick bench test while I already had my motor pulled from the saw cabinet. And really, if you can wire a light switch, you can wire this box as well. It is just a matter of bringing in your 240 volt 3 wires (2 hots and a ground, your neutral is not needed) to the VFD terminals L1, L3 and PE. Then off the VFD terminals T1, T2 and T3, run your wiring directly to your equipment's motor. It really needs to be a direst connection, no switch or anything in between.

Next, power up the VFD and see that you have voltage. The drive is defaulted to initially run at 5 Hz. Then press the run key on the VFD and note the motor direction. If it turns the wrong direction you can swap T1 and T2. Once you're satisfied with the direction change the frequency to 60.

That's all there is to testing it. The rest of the settings all deal with preferences. For instance, I have set my acceleration time to 10 seconds (default was 5) and deceleration to 10 (again default was 5). You can set it to coast to a stop or specify how quick you want it to stop. There are a lot of options you can select and they are all explained in the manual.

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This brings me to the only downside of the whole experience. I don't think the manual is difficult to understand but it is small, as is the print. You can see in the picture about the size compared to the CD that comes with the device. Thank goodness for the CD! It also contains a manual and once printed out is a lot more readable.

You will notice I have my VFD mounted to the wall a few feet from the saw without any enclosure. Again, advice from the folks at Practical Machinist really doesn't advise enclosing it although you can. Just make sure you following the specs in the manual to allow for adequate air flow. Heat is not your VFD's friend. Since I have a good dust collection system I just hit VFD with a puff of compressed air on occasion and it stays clean.

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I installed a motor switch between the VFD and my service panel just to keep from having to flip my breaker when I wanted to kill power to the VFD.

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I was able to use the original ON/OFF switch on the saw to control power to the motor as the VFD has low voltage terminals to control it remotely. Those are the small wires exiting the bottom of the box in the picture. I think I just used sprinkler wire for that. This is a lot better, not to mention safer, than trying to hit a little button on the face of the VFD while the saw blade is spinning.

Well that's it! I have been very satisfied with this product and may revisit this review at some point down the line after it has been in use to review its durability.