×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

E-motor with high rate start stop time per hours

E-motor with high rate start stop time per hours

E-motor with high rate start stop time per hours

(OP)


I need a little help for electric motor .
I need two type of Emotor with high rate start stop time per hours for my application
1- Unidirectional motor single(220 V) and there phase(380 V) with 200 start stop time per hours
2- Bidirectional motor single(220 V) and there phase (380 V) with 200 start stop time per hours
Range of power I need is 250 , 500 and 1000 watt

I speak with several E-motor seller but they informed me they could not offer any products . also I know in E-motor start time the amperage Consumption rate will increases and deepening of the brand it would be between 6 up to 12 time of nominal ampere. Soft start and driver is not acceptable for my application.
Anyone can advice a brand or products for above spec . or I should consider other type of e motor like servo or stepper motor ?
Please share your experience in this case ?

Thanks

RE: E-motor with high rate start stop time per hours

An electromagnetic clutch is not allowed? To avoid so high start/stop rates.

RE: E-motor with high rate start stop time per hours

A servo would work, but also you can use any standard* 3 phase motor and a VFD to accomplish this. Even though you likely do not need to vary the speed, the starting and stopping current will be controlled by the VFD, which is theoretically capable of limiting the motor starting current to the FLC (Full Load Current) of the motor. At 200 ops/hour however, that is one complete cycle every 18 seconds and that means your acceleration rate will have to be relatively short, even shorter if you need controlled deceleration, i.e. braking, between cycles. That then means that you are unlikely to be able to accelerate this with a limit of motor FLC, because that would extend the ramp time. But the VFD should be able to limit the acceleration current greatly compared to any other technology, i.e. 150% or less, compared to 600%, which will reduce the de-rating necessary for the motor. For sure though, you will need to use a motor larger than the load in order to allow it to absorb the excess heat without damage. I would also recommend getting a "blown" motor, i.e. one with a separately powered cooling fan that runs continuously, not just the one attached to the motor shaft.

* Standard "inverter duty" AC motor.

If you want more help you would have to post intimate details of the actual operation, including inertia, cycle descriptions etc., which may be too proprietary. This more likely needs the personal attention of a qualified engineer who can see and study the entire process in detail, even if it means signing an NDA. But for sure this is not the sort of thing that can be "napkin engineered" by a motor or VFD salesman. There are several such independent EEs that are members of this forum who can possibly work from afar, or post your general location so they can see if they are interested in helping locally.


"Will work for salami"

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources