Hoffman Controles makes an electronic speed control for single phase motors 120-480vac that will take a 4-20mA control signal. Model #708-BVmA or 708-CVmA phone #(972)243-7425. These controllers will only work with shaded pole or permanent split capacitor motors, all others will burn up.
Thanks for the great responses. We are presently working on a project that has around 150 pumps on these drives ranging in Hp from 5 to 200. I became very alarmed when we began to have so many failures on other jobs in the last few months. These pumps have a very critical application...
We have had the bearings on three centifugal pump motors on three different jobs fail. The pumps have been in service ranging 1 year to three months. We had the bearigs on one motor analyzed, they said the races were fluted (I think thats the right word) due to electric discharge. I know this...
Does anyone know of a method for calculating the noise level of a boiler blowdown. Boiler operates at 120 psig the blowdown piping is 8" approximatley 60' long venting 40,000 lb/hr to atmospheric pressure