In view of a breakdown, what would be the best condition monitoring strategy for a submissible pump driven by a motor which is colled by potable water? The pumps are completely submerged in the seawater and 2x100%. Flow rate 270 m3/h. Which CBM technologies are applicable and can be deployed? Any suggestions are welcome.

Since the Pump is driven by motor and is fully submerged (unable for physical inspection). The best way to do conditional inspection is closely monitor the motor Amps and power factor. Deviations can be set for alarm or trip.

of course other than process parameters. This article was recently downloaded by from internet. May be useful for your application.

P5-1_Solid_Plant_(SAO).pdf (59 Kb, 34 downloads) Motor Control

Josh:

The first questions are: Is there a history of failures in these motors? And, what were the failures?

If you are seeing mechanical problems, such as bad bearings, eccentric rotor (rotor rub) and electrical problems such as winding failures, then there are modern solutions.

Electrical Signature Analysis (ESA) and Motor Current Signature Analysis (MCSA) technologies can be used to detect the same types of problems that you would use vibration analysis on un-submerged motors. Motor Circuit Analysis (MCA) is used to detect winding contamination, insulation to ground, cable and developing winding shorts. These technologies do not require the pumps to be removed and all can be applied right from the controls.

Information on contacting the manufacturers of these technologies can be found in the 'links' section of the Institute of Electrical Motor Diagnostics, Inc. website (http://www.iemd.org).

Sincerely,
Howard

History: As attached for pump A & B (2x100%). Commissioned a year ago. Pump A kaput & B running now.

GA: The pump is driven by an electric motor. The pump-motor set is hanged from a platform floor and submerged in the seawater. The motor is below the pump (upside down intead of motor on top). The pump is directly coupled to the motor. The whole set is housed in casing. Power cable and coolant to the motor are run from platform floor along the pump-motor rising main pipe. There is also a dosing line to the bottom of the motor. The total vertical length is 3.5m. Flow capacity is 270 m3/h. Motor is 140kW.

Inspection: Mech seal stationary face broke into several positions. Motor bearing badly damaged and bushes completely worn out.

So any ideas what can cause these effects?

This message has been edited. Last edited by: Josh,

Nilesh, the write up you sent is quite advanced. Also, I've read something about monitoring the motor amps and power factor for pump motor condition monitoring. The most effective is monitoring the power consumption to ensure the pump operates at its best efficiency point (BEP). However, it looks like we need to add on a special device (called power cell) to the existing motor control centre (MCC) to monitor this, right? Can that Simocode do this?

This message has been edited. Last edited by: Josh,