protecting your vac blowers/motors.

[knight_toolworks]

with one dead regenerative blower dead (shorted out) I wanted to make sure it did not happen again. so the question was how much air should the blower/vac motor get? all I could find are fuji's vacuum relief valves are set for 10% below the max " the blower can pull.
so for this blower thats about 6.5" but after talking to an electrician he recommended using a inline ammeter to keep a eye on amps over heat or " so when the blower is running with the relief valve set right it only pulls around 8.9 amps when it is rated for 10.3 amps max. so I wonder if the 10% lower " is accurate? anyway here i my setup to keep track. the meters are dirt cheap about 14.00 each off of amazon. this should work well with the black box motors easier then trying to read heat. also here is pic of the remote switches UI setup. a little bit tricky to figure out the wiring with magnetic starters I added the LEDS

http://www.amazon.com/gp/product/B00EC849VM?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00
http://i154.photobucket.com/albums/s266/knighttoolworks/posting/F39554EC-8768-4B3A-BB23-E2552C393664_zpsn0wnfyfe.jpg

http://i154.photobucket.com/albums/s266/knighttoolworks/posting/92BAA3DC-39C8-422E-A344-5D830E74133C_zps5pgfyl4y.jpg (http://s154.photobucket.com/user/knighttoolworks/media/posting/F39554EC-8768-4B3A-BB23-E2552C393664_zpsn0wnfyfe.jpg.html)

[ntraub01]

In addition, all vacuum/blower motors need to have access to free air and we need to run the motors on free air for at least 4-5 minutes BEFORE we shut them down. Our initial install did not include a free air option and we were quite lucky we didn't loose any of the motors. We did however manage to heat soak the motors well enough that it melted the plastic impeller which unto itself was a real PIMA but thankfully it did not cost us a motor. We also don't cycle our motors between each sheet of material we are cutting. We close all valves to the vac table, open the free air valves and then start the process of clearing the table, cleaning and reloading, all while the motors are still running but because they are on free air they are also cooling down before the next cutting sequence.