Transformer size question-conflicting info? - Page 2
Close
Login to Your Account
Page 2 of 2 FirstFirst 12
Results 21 to 22 of 22
  1. #21
    Join Date
    Nov 2019
    Country
    UNITED STATES
    State/Province
    Colorado
    Posts
    6
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    0

    Default

    thanks again Bill, good information. I heard back from one source that matched it up to 6KW, but the price is killing me. I did find another on a used site that is the same thing and half the price. If no one else calls back I might just roll the dice on the cheaper one. The distances of box to RPC to transformer to Lathe are all around 10 feet.

  2. #22
    Join Date
    Jun 2001
    Location
    St Louis
    Posts
    18,040
    Post Thanks / Like
    Likes (Given)
    1892
    Likes (Received)
    3044

    Default

    "Withstanding the surge" is a good bit different from "holding up voltage during the surge".

    To get a full power normal start you need to pretty much keep up the voltage during the start, which may pull 5x normal full load amps. If you just need to get the motor started turning, and are not doing that under load (lathe has a clutch, etc), then you can tolerate a fair bit of voltage drop.

    Reduced voltage starters may create a voltage drop to 58% of normal line volts, routinely, and the motor starts fine. But those are motors that are not necessarily expected to start at full torque.

    Your case is probably in-between, wher you need to start the motor and work spinning, meaning overcome inertia, but are not going to have to start against a cut, etc. So oversizing somewhat is OK, but extremes are not needed.


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •