Announcement

Collapse
No announcement yet.

Another VFD wiring question

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Another VFD wiring question

    Trying to get the Tree 2UVR up and running this weekend.

    This is what's in the box that currently mounted to the side of the machine



    There appear to be 2 main disconnects, one for the spindle motor and one for the power feed motor. Then on the bottom there is a transformer that feeds both of these main disconnects.

    The manuals that came with the VFDs (one is a TECO and the other a GE) are more confusing than helpful.


    Am I correct in thinking that I can get rid of all this stuff, run 2 supply legs into the VFD's, and the 3 respective load wires out to each motor (along with grounds) and call it good?

    This would leave the VFDs powered up all the time. Are you supposed to have disconnect between the powersource and VFD?

    About the For/off/rev switch on the spindle motor.....I understand that this is to be removed and the forward/rev switching done through the VFD somehow?
    Last edited by lbhsbz; 11-26-2010, 03:21 PM.

  • #2
    Personally I always leave a spindle contactor in place and drop it out when in E-Stop condition.
    The STOP/START FW/REV is through low level contact closure inputs.
    Max.

    Comment


    • #3
      I just wired up a Reid automatic surface grinder with two VFD's - one for the spindle motor and one for the table motor.
      I junked that entire control box you show in your pic.
      I'll be glad to answer any questions if your setup is similar.
      "Patriotism is the last refuge of a scoundrel"

      Comment


      • #4
        I am no expert, but I wouldn't leave your VFDs powered all the time. I recently installed one and I removed all the contactors and replaced them with a 20amp breaker box that also serves as the on/off for the VFD.

        Two things to note, set your VFD to shut the machine down if there is a power blip (should be a factory default). Secondly, don't switch the output power legs but use the logic switch circuits to do your fwd rev estop.

        be
        Last edited by bewards; 11-26-2010, 10:37 PM.

        Comment


        • #5
          Originally posted by jep24601
          I just wired up a Reid automatic surface grinder with two VFD's - one for the spindle motor and one for the table motor.
          I junked that entire control box you show in your pic.
          I'll be glad to answer any questions if your setup is similar.

          I would love to see photos and hear details of what you did. I need to re-wire the huge box on a Van Norman #12, and I would rather use 2 VFDs, one for the small table feed motor and one for the spindle motor than the 1942 vintage wiring in a big box.

          Thanks.

          Comment


          • #6
            Here is a before and after of the control box. On the left was the on-off switch. A cable came down from the table reversing switch and a power feed to the table motor went through the little round opening to the motor on the other side of the machine. I kept the cable from the reversing switch (after figuring which of the wires did the switching and then wired them to phone wire (in the little new box) which I then ran through the round opening to the table motor VFD on the other side of the machine, discarding the old power feed in the process.

            I could have put the little new box over the round hole but I ran it to the front of the machine so I can put a start or stop switch there if I choose later. You can see the outline of the old box.


            I mounted the VFD's to the column of the grinder - in this pic they are clamped in place with G-clamps.


            This view shows how I ran the various cables. The box under the table motor VFD has a switched socket for the sump motor and an unswitched socket for other uses. Note the phone wire running up to the VFD and the motor feed running from the VFD down to the motor.
            Last edited by jep24601; 11-27-2010, 01:55 PM.
            "Patriotism is the last refuge of a scoundrel"

            Comment


            • #7
              More questions - the transformer - is it a control voltage transformer - 24 v?
              If so then your contactors must have 24 v coils. Using the contactors as switches will require having the transformer powered up to run the contactor coils.

              I just wired a teco VFD last week. The VFD will supply control voltage for the For/Rev function if you use external switching, or it can be done on the VFD. Same goes for the variable speed- my model has a dial on the VFD.

              Some programing is needed but is easy to do.

              If you don't want to unplug your FVD then I would install a switch or use the contactors as opposed to leaving it powered up all the time.

              EDIT - It looks like those contactors might have motor overload protection. The teco recommended fuse protection.
              Last edited by Abner; 11-27-2010, 02:11 PM.

              Comment


              • #8
                JEP,

                Can I see inside the "little new box" please?

                And when you say "phone wire", would that be any twisted pairs of wire that will hold 24V DC for the controls?

                Thanks again.

                Comment


                • #9
                  Herewith "inside the little new box". The table reversing switch had 5 wires. With a tester I found which two wires tripped for forward and reverse to a third wire - the common. The other two wires (black and white taped off) are dead. You can see the three control wires simply spliced to three of the wires of a standard 4 wire phone cable. The fourth (black) unused wired I could wire for an emergency off (usees the same common wire).

                  "Patriotism is the last refuge of a scoundrel"

                  Comment


                  • #10
                    Well, I got it all up and running.



                    I didn't end up using a disconnect quite yet, I just put it on a plug...unplug it when I'm done for the day.

                    I removed the factory switch and wire nutted the 3 supply legs to the 3 sets of coupled wires to the motor. I'll machine up a new box and put a double pole toggle switch in there for forward/off/reverse if I can figure out how to program the Teco drive to accept these inputs

                    Comment


                    • #11
                      Nice tidy job IBH.
                      "Patriotism is the last refuge of a scoundrel"

                      Comment

                      Working...
                      X