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Quick VFD wiring question

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  • Quick VFD wiring question

    Hi guys!

    This is my first post here. Looks like a good place.

    After a failed attempt at wiring a phase a matic to my new Clausing 5914, I would like to try to wire up a VFD (Hitachi WJ200 2HP). All I need to do is provide power to the machine, the VFD will remain at one frequency.

    My quick question is this- Is it really that simple to wire these up? It is single phase, so two hots from my 220V IN, and 3 hots out to the machine?

    Which color wire goes where on the VFD output?

    I read that VFD needs to be wired in between the motor and the switch? Is this correct? Can I just plug in the existing power wire to the VFD and not mess with anything on the machine?

    The wiring goes from the wall to a box to the motor and drum switch.

    Thanks for your help, I don't want to fry anything here. Is frying the electronics a likely scenario if I screw up the wiring? Or are there built in failsafes?

    Last edited by ritzblitz; 12-23-2013, 10:29 PM.

  • #2
    The wj200 is pretty tough, but you can easily fry it if you do something dumb. And even though it's possible with some vfd to switch the outputs between the motor and VFD, Hitachi specifically says not to.

    I recently converted a 6913. The original drum switch (same as the 5914) was repurposed to provide LOW VOLTAGE inputs to the WJ200 for Forward, Stop and Reverse. In my case the lathe had a Clutch and Brake, so the vfd was programmed to not use programmed deceleration as it runs independent of the drive train. Relatively easy with a little experience, but you do need to be able to read the manual and set the vfd registers to other than the factory defaults.

    If you are really as electrically challenged as you suggest in your other (PM) post, you might want to seek some local assistance; there more to wiring a vfd (or any machine) safely than can be assumed from base knowledge of zero. The manual covers which wire goes where, but yes, in the simplest configuration it's 2 wires (240v) plus ground in, and 3 wires plus ground out.

    Does your machine have a both the brake and clutch?

    BTW.. the Phasematic static converter will work if you wire it correctly.

    Where are you from? Please fill in your location (profile0. Electrical advise is meaningless unless we know which county you are in.
    Last edited by lakeside53; 12-24-2013, 06:02 PM.


    • #3
      Hey Lakeside,

      Thanks for the reply. Yes I am fairly electrically challenged. I wish I wasnt, it has just never clicked for me.

      However, I am not stupid and I can follow instructions well.

      My machine has a brake and a clutch yes.

      So are you saying that I can just wire it up and go? Or do I need to wire it into the drum switch with a low voltage (how do I change voltage?). Do the locations of the motor wires on the VFD matter? Can I just randomly plug them into the VFD? Like I said, I am purely looking to supply 3 phase power to the lathe. The variable drive is in good condition, I just need to get it up and running.

      The milling machine will be the bigger challenge.


      Whoops, forgot my location.

      I'd like, for my own sanity, to get the static converter working. It would be an accomplishment. I'm gonna hook it back up to the milling machine (where it lived before) and assure that it functions. Then maybe I can figure out what's going on with the lathe side.

      Can you offer any advice on the static converter? I tried different positions of the wires but no dice (probably not the best idea to go switching outputs around?)
      Last edited by ritzblitz; 12-23-2013, 11:08 PM.


      • #4
        If the static phase converter was a challenge, I'd say that a VFD is way beyond your skills. And if you want to be able to reverse the load w/o risking the VFD the drum switch will require rewiring so that it tells the VFD to run the motor in the selected direction as well as starting and stopping the motor. The VFD then is connected directly to power and to the motor.


        • #5
          You need to remove the power wring from the drum switch and connect the vfd directly to the motor. The drum switch will be then need be connected with just three wires plus signal ground directly the vfd programmable Low Voltage inputs. The "low voltage" is provided by the vfd.

          Poor choice, but... the Static converter will work if you wire it correctly.
          Last edited by lakeside53; 12-24-2013, 06:03 PM.


          • #6
            Did you look at the instruction book?
            This kind of thing is usually spelled out pertty well.
            If it was not clear, Wire the VFD directly to the motor with no switch.
            The rest you can't mess up too badly.



            • #7
              Thanks guys.

              I did look at the instruction book. The CD was much better. I'm going to read it more carefully tomorrow.

              I'm going to be taking the rewire drum switch route.

              Static is only a challenge because I am uncertain of why it is not working. I have wired it up the way it said in the instructions I found.

              I appreciate the help, thanks for helping a noob

              Side question, but I'm trying to learn.. Why does the voltage across the drum switch drop to zero when I put it in forward or reverse? On two of the poles it is 120v in the off position.
              Last edited by ritzblitz; 12-24-2013, 12:24 AM.


              • #8
                I am afraid you are in the deep end of the pool way, way over your head!
                The voltage across an open switch drops to zero when you close the switch because you cannot measure potential across a dead short.
                Find someone in your area that knows what a VFD is and how it operates pay them in money or beer and save yourself the cost of a new VFD or a trip in the meat wagon.
                Sorry to be blunt.


                • #9
                  Yes, if you want to learn about electronics, the place to start is NOT an industrial VFD and induction motors on mains power. I would suggest one of the many experimenter kits you can get, where you can start with safe low voltage projects until you become more knowledgeable and confident in your abilities. And hopefully you will make many mistakes (as I did while learning) on circuits where the damage and risk of injury are minimal. Even low voltages can be dangerous. If you wire an electrolytic capacitor backwards, or even try to put too much current through it, it will overheat and explode with enough force to put out an eye or cause painful burns. Whatever you do, at least wear safety glasses. And other common sense rules are to take off any conductive items like rings and watches with metal bands, and keep one hand in a pocket when poking around with or without a meter.

                  One basic concept that took me awhile to "get" was that voltage is always between two points, and current is always through a conductor or component. There are also no perfect conductors or insulators, so there will always be some voltage across what appears to be a "dead short", and there will be some current flow through an insulator (and even air or vacuum). Also, any instrument you use to take a measurement will have some effect on the circuit, and there is always some error in any measurement.

                  Something else to bear in mind is that there can be voltage present in a circuit or component which is not connected to AC or batteries, because capacitance may be present. A large motor or transformer or even a length of coaxial cable can retain a high voltage for a long time, and it can cause a very high current surge which may result in an arc flash or shock. And anything with inductance (such as a motor, transformer, or electromagnet) can hold a lot of stored energy, and even if you are using a 1.5 volt battery, it can generate hundreds of volts if you break the circuit (as I found out when I was a kid).

                  Good luck, and be safe!
                  Paul , P S Technology, Inc. and MrTibbs
                  USA Maryland 21030


                  • #10
                    Can't delete response. Won't return from "Save". System OK?

                    Oops! It's OK now.

                    RitzBlitz. I know a little about drives etc and a few others who posted here are more knowledgeable than I. A few post are not to be counted on but which is which?

                    You, as an electrical noob, haven't the means to distinguisih good technical advice from bad. Here's good non-technical advice: find a local motor and drives guy with actual credentials and either pay he fee or bribe him with pizza or a home cooked dinner to save your bacon. Cheap compared to screwing up your drive or spending days or weeks in impotent frustration.

                    There's still lots of industry in Allentown. Look in the Yellow Pages under "motors and controls" The Yellow Pages are still the quickest way to track down local resources.

                    Hard to beat having an expert handy to direct your moves.
                    Last edited by Forrest Addy; 12-24-2013, 08:46 AM.


                    • #11
                      Again, thanks for the replies.

                      I'm glad you all take the time to respond to someone with zero knowledge and not bash.

                      I think I am beginning to wrap my head around the basic circuitry to control the lathe with the drum switch through the VFD.

                      I may be in the deep end of the pool but I'm not drowing (yet).

                      As I am wiring the VFD in nearly it's most basic setup, I will continue to pursue this and get help if I get stuck.


                      • #12
                        You could throw the drum switch away and just use simple pushbuttons - that's what I did.
                        "Patriotism is the last refuge of a scoundrel"


                        • #13
                          Yeah I could do that. However, I would like to retain the original functionality of the fwd/rev switch on the machine.


                          • #14
                            Ok, in my other thread on PM, I was asking about this phasamatic static converter I've been trying to get working.

                            I rewired it to my milling machine, where it had worked before when I inspected the machine under power. Now at my shop, no dice. No humming, no red light, nothing. Same with the lathe.

                            Testing with my voltmeter, I get 120V at each lead in the conduit box (A,B,C). This is puzzling to me. Why doesnt anything happen??

                            Not sure if this matters, but I have a 15A breaker supplying the 220v.


                            • #15
                              Originally posted by ritzblitz View Post
                              Yeah I could do that. However, I would like to retain the original functionality of the fwd/rev switch on the machine.
                              Sure complicates a VFD hookup but if you can figure out how to do that all the more power to you. The lever forward/off/reverse switch on my LeBlond regal was sure a pretty switch but there is something to be said for simple wiring and with a VFD it can be very simple.
                              "Patriotism is the last refuge of a scoundrel"