How do high load RPC 's differ from Regular load RPC 's
Close
Login to Your Account
Results 1 to 7 of 7
  1. #1
    Join Date
    Nov 2011
    Location
    Alberta
    Posts
    480
    Post Thanks / Like
    Likes (Given)
    50
    Likes (Received)
    118

    Default How do high load RPC 's differ from Regular load RPC 's

    I am looking at the American Rotary phase converters and I would like to know how the heavy load converters differ from there regular converters. What components are used to allow them to start heavy start loads.
    Thanks for any insights

  2. #2
    Join Date
    Jun 2001
    Location
    St Louis
    Posts
    17,843
    Post Thanks / Like
    Likes (Given)
    1788
    Likes (Received)
    2970

    Default

    Do not know their stuff well..

    In a complete RPC (I think they sell complete units as well as panels), the idler would be larger, and/or made to have lower impedance, so it would not limit the starting current as much, meaning that which goes to the 3 phase load on the manufactured leg.

    For just a panel, I would not suppose there was a lot that could be done to start 3 phase loads better, since the panel has pretty much no influence once the idler is running, and balance depends on the idler. They would have to specify that the customer use a particular idler or type of idler....

  3. #3
    Join Date
    Mar 2018
    Country
    UNITED STATES
    State/Province
    New Hampshire
    Posts
    4
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1

    Default

    I'm not a 100% sure but I believe their regular load has run caps balance phase voltage at a set load, while their High load converter has a control board that monitors voltage and cuts in more capacitance to balance as needed.

  4. Likes TDegenhart liked this post
  5. #4
    Join Date
    Mar 2018
    Country
    UNITED STATES
    State/Province
    New Hampshire
    Posts
    4
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    1

    Default

    If you call them up and ask for tech. support you'll get a very knowledgeable living person who will happily answer your questions. They did for me at least.

  6. #5
    Join Date
    Nov 2011
    Location
    Alberta
    Posts
    480
    Post Thanks / Like
    Likes (Given)
    50
    Likes (Received)
    118

    Default

    Thanks for the insights, so would building a heavy start RPC be beyond the home build?

  7. #6
    Join Date
    Mar 2011
    Location
    Geneva Illinois USA
    Posts
    6,040
    Post Thanks / Like
    Likes (Given)
    2523
    Likes (Received)
    2343

    Default

    Quote Originally Posted by legoboy View Post
    Thanks for the insights, so would building a heavy start RPC be beyond the home build?
    By no means. You would just have to have a logic controller that senses voltage and phase angle of the generated leg, that as conditions change, be able to switch in and out balancing capacitors and be able to do this is a stable manner, and such that the capacitive inrush and residual charge doesn't destroy the switching elements among other things.

    For the timid let somebody else figure all this out.

    Tom

  8. #7
    Join Date
    Nov 2004
    Location
    Webster Groves, MO
    Posts
    7,184
    Post Thanks / Like
    Likes (Given)
    1802
    Likes (Received)
    3259

    Default

    I had a unit that sort of did that for many years. It supplied a two speed Dahlander motor on a mill and had a current relay that added capacity when the current was high. When starting the motor on low speed, the relay stayed open and the motor started fine on the run capacitor. When the motor was set on high speed, the relay pulled in and added capacity until it got up to speed, then dropped out. If I switched from low to high speed with the motor running, the relay would pull in, then drop out when the motor got up to the high speed. If you are running a lathe or mill, couple to a regular induction motor and put variable DC on its windings to make a dyno brake. Then it is just a matter of how much patience you have to find the capacity for a given load and adjust a relay to match. You can have as many as you want. I have done the same thing with a Variac set up to reflect a varying capacity and adjusted as I went. Problem is that the Variac would wear out. Actually, with good bearings and soft carbon brushes, it might hold up well. Then all you need is a voltage or phase angle detector to control a servo. You probably could do it with a voltage comparator that set it to match the line voltage. The phase angle would follow on its own.

    I don't know why people perversely keep using voltage relays when current relays work so much better.

    Bill


Tags for this Thread

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
  •