Non-seal Pump

[wookiyo]

1. What kinds of the Safe protection device of non-seal type pump are there?
2. What is the minimum requirement of non-seal(canned motor type)pump to be applied to safe protection device?

 

[nutriarat]

Are you working with a mag-drive or a canned motor pump? Power monitors are common on mag-drives, they work by monitoring the electric current drawn by the motor, too high or too low and the monitor trips the pump. Mag-drives can be very reliable but they do need some safeguards.

 

[checman]

It all depends on the installation application and or system the pump is installed in. Thermal couples or amp meters or pressure switches can all work well if they are installed in a system with constant operating conditions and with the proper delay’s and limits. The trick is finding the method that will shut the pump down dependably but not give nuisance trips. Most all magdrive or canned motor pump manufacturers have a pump monitor that incorporates the aforementioned in one way or another. Just be sure of the limitations of any device you look at and use one that is as fool proof as possible.

Regards checman

 

[vanstoja]

In canned motor pumps rated up to 1000 horsepower, conventional circuit breakers are employed for protection against locked rotor and current overload conditions. Locked rotor trip protection is usually based on rotor bar temperature rise time limits which may be of the order of ten seconds or less for high-power motors. In canned motors with fluid film bearings, bearing water temperature is often monitored by resistance temperature detectors(RTD) installed in wells immersed in the internal coolant flowpath and alarm temperatures are set around 250F for bearings employing carbon-graphite materials. Stator winding hotspot temperatures are also monitored by RTDs to prevent operating at temperatures in excess of the motor insulation temperature rating established by insulation class.