Overheated VTP motor
Overheated VTP motor
(OP)
75HP motor for a vertical turbine pump is overheated afer 100 hrs of operation , the pump is running at the rignt side of the curve, inaddition , a high vibration can be observed. can any one tell me what may cause this overheat ?? I think that running at the right side of the curve with higher flowrate than the duty point (or BEP) will increase the required NPSH which will quicken impeller failure. but how can this cause the overheat of the motor .
Note : the absoverd shaft power (output power) at the running point at the right side of the curve is about 35 hp, which is still less than the rated power of the motor. can you please help me in any idea or expectation for this cause of overheating ????
Note : the absoverd shaft power (output power) at the running point at the right side of the curve is about 35 hp, which is still less than the rated power of the motor. can you please help me in any idea or expectation for this cause of overheating ????





RE: Overheated VTP motor
RE: Overheated VTP motor
As to your 35 hp at runout on the curve...is this a single stage pump? Is the curve for a single stage? Oftimes, the curves provided are a single stage curve.
RE: Overheated VTP motor
RE: Overheated VTP motor
Any other ideas regarding the overheated rather than the overloading ?
RE: Overheated VTP motor
If the motor is inside of a room, is there sufficient cooling air available to the motor?
RE: Overheated VTP motor
You'll need all the nameplate data off the motor. It is entirely possible that a motor with no special insulation can overheat if it is in an enclosed space.
Typically, a standard motor will be a Class B insulation, which is capable of a 90 deg C temp rise, in a 40 deg C ambient. A higher ambient will leave you less room for temp rise.
RE: Overheated VTP motor
RE: Overheated VTP motor
The motor is of class F , AND 1.15 SF , WHICH allows 110c deg rise of temperature above the ambient. I didn,t reach this high tempreture yet but I,m still concern about this high temperature which is about 80 C deg.
Thanks for all your inputs
RE: Overheated VTP motor