Dear All
Please see attached picture. No data for hp or amps only volts, frequency and LRA any idea of the power rating?
Thanks
Petronila https://files.engineering.com/getfile.aspx?folder=0c8c55a3-c8a2-4f90-97d2-52a1d5af9f9c&file=York.jpg
Dear All,
I have seen some OEM use flexible jumpers for connecting the damper winding of the synchronous motors/generators (see attached pictures). I would like to know your inputs of what should be the justification for such design.
Thanks in advance
Petronila...
Dear All,
I would like to receive your inputs about how calculate/select this types of devices (thermistors, RTDs,thermocouples, etc.) based on insulation class of the stator windings.
Thanks and Regards
Petronila
Dear all,
Some lead manufacturers provide tables with the ampacity chart for electric motors that have been used mainly for AC machines but what about DC Machines? Does someone can share an ampacity chart showing the led size for DC Machines?
Thanks
Petronila
Dear all,
Does anybody have the formula to correlate the shaft dimensions (diameter and length) with the rated output (kW/hp) in one electric motor?
Thanks in advance
Petronila
Dear All,
If you have an ATEX (EX Proof)motor attached to a gear box does the gear box should be ATEX (EX)certified too? The gearbox is a non-electrical equipment thus how should be chossen?
Thanks and Regards
Petronila
Dear All,
The attached file is a graph used for lubrication intervals for bearings of electric motors, did someone recognize the source of the graph? If so can share the original document, if possible.
Thanks in advance...
Dear All,
I would like to know your pros and cons for using only one VFD for starting several motors. The application had four 350 hp 8 pole 3-phase motors involved and once the VFD starts the first motor then the second one is started using the VFD and so on. The problem here is some of these...
Dear all,
It is well known the skewed rotor bars in induction motors are used for avoiding CUSP, cogging and noise in three-phase induction motors. However, there is also the possibility of skewed slots in the stator. One of my collegues came to me looking for explantions of skewd slots in a...
Happy Holidays,
There are some cases when the redesign of a winding from concentric to lap, specially in 2 pole machines, results in a HIGH or DRASTIC reduction in the wire area per turn and sometimes the reduction may range from 5 % to 7 % or above. My question is if there is a formula or...
Dear All,
Sometimes we find some motors rated 460/575 v connected in Delta for 460 V and connected with a combined wye-delta connection for 575 V rated for the same hp at the same speed at both voltages(i.e. 100 hp 4 poles 460/575 v 60 Hz). See attached.
Thoughts why the manufacturer rated...
Dear All,
I am looking for a reliable test method/procedure for testing the damper windings in a salient pole rotor. See attached sketch.
The idea is to test the condition of the bars (detecting cracked or damaged bars or any abnormal condition of the whole damper winding) without dismantling...
Dear All,
There are some OEM that designs 2 pole motor using 12 groups rather than 6 groups and connecting in series one group with the inmediatelly adjacent group forming a group with the double of coils, (i.e. 2 pole-36 slots with 12 groups of 3 coils pitch 1-14,16,18).
Can somebody share a...
Dear All
As you know, there are submersible pumps with the winding cavity filled with oil. This oil should be obviously dielectric oil. However, the main concern here is the oil should be compatible with the insulation system of the winding. Usually the oil is refined paraffinic type.
Does...
Dear All
Usually, in large motors that are internally connected in parallel stars (3Y-4Y-5Y-6Y, etc.) we found all stars connected with a star ring. When repairing, make sense to use the same wire/conductor size that we found in the original winding, but there are some cases where repair shops...
Dear all
SCIM is powered with VFD and but Inverter Duty rectangular wire is not available for rewinding. Winding was not stripped yet so I can´t calculate the volts/turn but due to the stator winding will be subjected to very high temperatures and dv/dt´s I doubt mica over film will works...
Dear All
First of all I want to wish you a Happy Holidays
I found a name plate with bearing information in a nameplate
Motor manufacturer is using the terminology DE Bearing: EBKL 6304 C3/---- and NDE Bearing: EBRL NU ...
Did you know the meaning of EBKL and EBRL?
Thanks
Petronila