You’re close! Replace the existing fan motor with a 3 phase motor with class F (or H) insulation powered by a VFD fed from the existing single phase. This was alluded to in post 4.
Exhaust Fan Motor "Burning Up."
- Thread starter TwoBlocked
- Start date
TwoBlocked
Senior Member
- Location
- Bradford County, PA
- Occupation
- Industrial Electrician
Yeah, but ain't gonna happen due to cost.
It might cost less in the long run if motors no longer fail.
ptonsparky
Tom
- Occupation
- EC - retired
Getting a VFD to operate in those conditions would require some planning for sure, but I agree.
Eta: Yes, move it out of the immediate area.
going_commando
Member
- Location
- NH
For the sake of argument, a 3hp 3-phase explosion proof motor can be had for under $1000. From my poking around a 2 hp single phase explosion proof motor is north of $2k. Depending on where you can install stuff (size of classified area), it may not be that much more to put in a motor with F class insulation and run it on a VFD. Something to consider.
If the classification is D2, an explosion-proof three phase motor wouldn’t be required.
MTW
Senior Member
- Location
- SE Michigan
That's the reason I suggested a sealed Tubeaxial style fan. If the discharge stack is extended upwards away from the drive, it removes the drive from the hazardous discharge zone. Combine that with an spark resistant aluminum blade and that gives you a unit suitable for conveying and discharging flammable gasses and vapors with approved means. Suitable for elevated temperatures as a plus. It also can be provided with a Standard 1Φ or 3Φ motor as desired.
It's been the standard in painting and baking systems for almost a century. Very low maintenance other than belt adjustments and replacements