Page 3 of 3 FirstFirst 123
  1. #21
    I use an "inverter" that works on the voltage-doubler principle - it was a bit of a bodge by a now-out-of-business company who grafted a voltage-doubler to the front of what is quite a nice ABB 380V VFD but it does mean single-phase 240V in and 400V or so 3-phase output. It works fine until you put a heavy load on it when the effectively half-mains frequency input means that the DC voltage sags too much between cycles and the VFD trips. I've been kicking around the idea of finding a 3KW 240-415V transformer and go back to the original ABB VFD input arrangement - and a cheap transformer has not found its way to my workshop yet - or try one of those Ecogoo 240-380V boxes (I linked to this company in an earlier post on this thread). They seem to deliver a lot of performance for the price, if they work as well as they claim...

    My lathe has a mechanical variable-speed mechanism so I have no experience with dual-speed motors and VFDs. In fact, I run the VFD at 50Hz output, with a switch that drops this to 25Hz for a quick low-speed option.

  2. #22
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 6 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,220. Received thanks 245 times, giving thanks to others 5 times.
    Quote Originally Posted by cropwell View Post
    GH-1440A ? You could always ask Warco for their advice. Is the problem that you have moved the lathe out of the 3 phase environment ?
    It's not specifically a Warco model. Like lots of Chinese built machines, it'll be produced by a factory who will stick whatever logo you want on it, and give you a few different specification variations. Plus as it uses a pretty conventional naming convention (Gear Head 14" swing 40" between centres), it may of even came out of different factories, with some copies better than others (aka Sieg/Syil).

    A quick google for GH-1440A brings up Warco, ToolCo, ETS, and Acra currently supplying that model. I'm sure there will of been more suppliers over the years.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  3. #23
    Quote Originally Posted by Neale View Post
    I use an "inverter" that works on the voltage-doubler principle - it was a bit of a bodge by a now-out-of-business company who grafted a voltage-doubler to the front of what is quite a nice ABB 380V VFD but it does mean single-phase 240V in and 400V or so 3-phase output. It works fine until you put a heavy load on it when the effectively half-mains frequency input means that the DC voltage sags too much between cycles and the VFD trips.
    Sounds like they missed a trick and only used a half wave voltage doubler and/or got the capacitor sizes too small. The full wave voltage doubler circuit works pretty well if you do the sums for the output power and choose the right size caps, but it does have twice the component count of the simple circuit.

  4. #24
    Quote Originally Posted by m_c View Post
    It's not specifically a Warco model. Like lots of Chinese built machines, it'll be produced by a factory who will stick whatever logo you want on it, and give you a few different specification variations. Plus as it uses a pretty conventional naming convention (Gear Head 14" swing 40" between centres), it may of even came out of different factories, with some copies better than others (aka Sieg/Syil).

    A quick google for GH-1440A brings up Warco, ToolCo, ETS, and Acra currently supplying that model. I'm sure there will of been more suppliers over the years.
    I mentioned Warco as it is green with ali info plates - as you say Chinese, probably from the weiss.com.cn stable. I can see why you are going for a VFD as £800 for a rotary converter - OUCH !

    Cheers,
    Rob
    Albert Einstein may have been a genius, but his brother Frank, was a monster

    Having just moved to Windows 10 (which is crap) My stress levels are through the roof !!!

  5. #25
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 6 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,220. Received thanks 245 times, giving thanks to others 5 times.
    Quote Originally Posted by cropwell View Post
    I mentioned Warco as it is green with ali info plates - as you say Chinese, probably from the weiss.com.cn stable. I can see why you are going for a VFD as £800 for a rotary converter - OUCH !

    Cheers,
    Rob
    I'm pretty sure even Chester used to supply certain models in green, so I never mention makes unless it's clearly mentioned on the machine.

    Rotary phase converters are pricey. The step-up transformer and motor are the big cost. The rest of the bits for a basic rotary aren't that expensive. A few big capacitors, and either a time delay relay (or voltage sensitive relay if you want to get fancy) plus some wire and terminals are pretty cheap.

    I used to have a link to a website that provided kits, including the option for electronic capacitor switching, but I can't currently find it. I was always tempted to upgrade my rotary with it, to eliminate all the relay/contactor chattering mine does when I start the milling machine up.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  6. #26
    Hi again do you think that a Rotary phase converter would be better than a digital phase invertor the problem is that they are all so pricey to be able to run the dual speed motor.

  7. #27
    My guess is that the rotary converter would be more robust. The reason is that the two speed switching would mean, that to be safe with an electronic converter, would ALL have to be powered down before motor is reconfigured for the other speed, otherwise there could be a momentary open circuit or short to blow the output gates.
    Albert Einstein may have been a genius, but his brother Frank, was a monster

    Having just moved to Windows 10 (which is crap) My stress levels are through the roof !!!

Page 3 of 3 FirstFirst 123

Similar Threads

  1. wiring V1000 VFD from a 2.2kw Chinese invertor
    By dek667 in forum Control Hardware & Systems
    Replies: 1
    Last Post: 10-08-2018, 10:03 AM
  2. What machine is required please
    By Arzo10 in forum Machine Discussion
    Replies: 19
    Last Post: 06-03-2016, 12:01 AM
  3. WANTED: Off-cut required.
    By Wal in forum Items Wanted
    Replies: 8
    Last Post: 14-12-2015, 11:09 PM
  4. Replies: 0
    Last Post: 08-07-2014, 03:11 PM
  5. NEW MEMBER: Help required
    By Vespa Mad in forum New Member Introductions
    Replies: 1
    Last Post: 24-06-2009, 02:06 PM

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
  •