urgent - rotor replacement spec
urgent - rotor replacement spec
(OP)
Within the next hours I am interested to hear any comments of good stuff to include in rotor replacement spec.
I'm starting with basic: shall be capable of accelerating the driven load under conditions of 80-110% terminal voltage without injurious heating to the rotor or motor.
I'm starting with basic: shall be capable of accelerating the driven load under conditions of 80-110% terminal voltage without injurious heating to the rotor or motor.





RE: urgent - rotor replacement spec
The rotor design will essentially determine the LRC and LRT of the motor, the full load slip and the maximum load inertia that the motor can start.
Unfortunately, a low slip rotor, which improves running efficiency, will generally result in a high Locked Rotor Current and a Low Locked Rotor Torque. Some specialised designs with thin deep rotor bars can achieve good starting characteristics as well as running charateristics, but can be limited in maximum load inertia.
Keep up the good work,
Best regards
Mark Empson
http://www.lmphotonics.com
RE: urgent - rotor replacement spec
RE: urgent - rotor replacement spec
Anything major that was missed? I remember once vanstoja commented on this forum about somehow monitoring actual rotor end ring temperature during a start and establishing a spec limit somewhere in the neighborhood of 250C (?). (That thread appears to have disappeared unfortunately.) The manufacturer indicated this monitoring was not feasible.
RE: urgent - rotor replacement spec
when you say rotor replacement, I presume that you intend to use the existing stator. In such a scenario, wouldn't only supplier from whom you can get this rotor be the original manufacturer ? (since a new rotor from another manufacturer would be expensive given his tooling and design costs).
So, if the supllier for your replacement rotor is the OEM, who knows all the design data, I don't understand why you should give them any specs ? or for that matter, why they should refuse to give an identical rotor as the existing one so that you don't have to reset all your relays ?
RE: urgent - rotor replacement spec
1. Manufacturer shall provide computer simulation results of the motor being "capable of accelerating the driven load under conditions of 80-110% terminal voltage without injurious heating to the rotor or motor."
2. The motor load characteristics and duty should be induded in the spec or to be made available to the motor manufacturer.
3. Obviously, there might be a suitable clause included in the spec regarding "Motor Warranty".
RE: urgent - rotor replacement spec