Need help on Wiring Allen Bradley 160 series C VFD in Hardinge TM mill
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    Default Need help on Wiring Allen Bradley 160 series C VFD in Hardinge TM mill

    I am wiring a Allen-Bradley 160s-aa04nsf1 ser c VFD into my Hardinge TM mill. My VFD is a 240V single phase in and 240 3 phase out.


    I wired TB1 so that my single phase hot lines are on L2 and L3 and my neutral on the ground connector.

    I have wired TB2 so that I have my motor T6 wired into my VFD U, my motor T4 wired into my VFD V, and my motor T5 wired into my VFD W. I have my motor T1,T2,T3 connected together.

    I have a question: should I run my motor ground to the TB2 ground screw directly or should I connect both the motor ground and VFD ground to my milling machine chassis ground?

    The picture of the VFD in the manual looks like the ground screws on TB1 and TB2 are connected. I have my 240V single phase neutral on the TB1 ground. Would I have a ground loop if I connected the motor ground to the single phase neutral? I know that the single phase neutral is at ground somewhere. I have a UFER ground in my house that is for my formal ground (green wire). My motor is supposed to be grounded to the chassis at the motor too (according to the schematic).

    Please advise if I should hook the motor ground to the TB2 ground only, or if I should tie this ground into the milling machine chassis ground (from the green wire).

    Thanks,

    Dave

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    Quote Originally Posted by techymechy View Post
    I am wiring a Allen-Bradley 160s-aa04nsf1 ser c VFD into my Hardinge TM mill. My VFD is a 240V single phase in and 240 3 phase out.


    I wired TB1 so that my single phase hot lines are on L2 and L3 and my neutral on the ground connector.

    I have wired TB2 so that I have my motor T6 wired into my VFD U, my motor T4 wired into my VFD V, and my motor T5 wired into my VFD W. I have my motor T1,T2,T3 connected together.

    I have a question: should I run my motor ground to the TB2 ground screw directly or should I connect both the motor ground and VFD ground to my milling machine chassis ground?

    The picture of the VFD in the manual looks like the ground screws on TB1 and TB2 are connected. I have my 240V single phase neutral on the TB1 ground. Would I have a ground loop if I connected the motor ground to the single phase neutral? I know that the single phase neutral is at ground somewhere. I have a UFER ground in my house that is for my formal ground (green wire). My motor is supposed to be grounded to the chassis at the motor too (according to the schematic).

    Please advise if I should hook the motor ground to the TB2 ground only, or if I should tie this ground into the milling machine chassis ground (from the green wire).

    Thanks,

    Dave
    You need "PE", "protective Earth" AKA "Ground".

    But where in your VFD's manual does it ask for a Neutral at all?

    And IF it needs it, why does it not have a terminal FOR it?

    One that is separate from "Ground" and so marked?

    Grounding & bonding of electrical systems | NFPA

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    Howdy,

    Thanks for the reply. The VFD manual does not directly ask for a Neutral. The manual is confusing, in my opinion.

    I have four wires 240V single phase coming to my mill from the wall outlet; 2 hot wires (black and red), 1 neutral (white), and one ground (green). The Green wire is ultimately tied to earth ground at my house. I understand that the neutral is grounded somewhere in the power system. I have 120V between the white and the red/black wires, and 240V across the black/red wires.

    Here is the mill schematic. hardinge_tm_wiring_diagram.jpg

    I currently have my black and red 240V single phase wires running to L1 and L3, respectively, and my white (neutral) running to L2. I have a fused disconnect and a motor starter upstream of my VFD. I am wiring from the motor starter (LEL) to the VFD directly.

    I currently have 7 wires coming from my motor: T1, T2, T3 (which are tied together); T4, T5, T6 (which are connected to TB2 on my VFD); and a ground (green wire) which is connected to the chassis which is tied to my earth ground (GREEN wire). T1,T2, and T3 tied together insures that the motor is running in high speed operation. The milling machine schematic noted that the motor is chassis grounded at the motor itself as well as chassis grounded in the electrical control panel. Chassis ground is connected to the green wire (earth)ground.

    Thanks for the link explaining Bonding and Ground. Here is the manual for my VFD and the source for my confusion:

    https://literature.rockwellautomatio...m009_-en-p.pdf

    The VFD manual only alludes to a ground on the 1 phase input to TB1 and a ground from my TB2 to the motor. The VFD only has 3 screws on the TB1 input (ground, S and T). I assumed that the neutral should go to the ground screw and that the black goes to S and that the red wire goes to T. If the neutral does not go to the ground screw on TB1, where does the neutral go?

    I'm wondering if I should connect the TB2 ground screw on my VFD to the chassis ground (which is connected to earth, green wire ground) and the neutral (white wire) to TB1 ground screw? The manual alludes that the ground on TB1 and TB2 are connected but does not directly state this.

    I'm wondering if I should not use my white wire at all and only go to chassis ground (green wire) on both TB1 and TB2? This seems super odd to me but is what the manual is directly dictating. I have NEVER wired 240V-1 phase without using the neutral. I would be depending on using my houses earth ground to support all of the power being delivered to my mill - which seems super odd.

    The confusion comes from Figure 2-2 on page 2-3 (page 15) and the discussion of motor wiring on page 2-6 (page 18).



    Dave

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    Quote Originally Posted by techymechy View Post
    Howdy,

    Thanks for the reply. The VFD manual does not directly ask for a Neutral. The manual is confusing, in my opinion.

    I have four wires 240V single phase coming to my mill from the wall outlet; 2 hot wires (black and red), 1 neutral (white), and one ground (green). The Green wire is ultimately tied to earth ground at my house. I understand that the neutral is grounded somewhere in the power system. I have 120V between the white and the red/black wires, and 240V across the black/red wires.

    Here is the mill schematic. hardinge_tm_wiring_diagram.jpg

    I currently have my black and red 240V single phase wires running to L1 and L3, respectively, and my white (neutral) running to L2. I have a fused disconnect and a motor starter upstream of my VFD. I am wiring from the motor starter (LEL) to the VFD directly.

    I currently have 7 wires coming from my motor: T1, T2, T3 (which are tied together); T4, T5, T6 (which are connected to TB2 on my VFD); and a ground (green wire) which is connected to the chassis which is tied to my earth ground (GREEN wire). T1,T2, and T3 tied together insures that the motor is running in high speed operation. The milling machine schematic noted that the motor is chassis grounded at the motor itself as well as chassis grounded in the electrical control panel. Chassis ground is connected to the green wire (earth)ground.

    Thanks for the link explaining Bonding and Ground. Here is the manual for my VFD and the source for my confusion:

    https://literature.rockwellautomatio...m009_-en-p.pdf

    The VFD manual only alludes to a ground on the 1 phase input to TB1 and a ground from my TB2 to the motor. The VFD only has 3 screws on the TB1 input (ground, S and T). I assumed that the neutral should go to the ground screw and that the black goes to S and that the red wire goes to T. If the neutral does not go to the ground screw on TB1, where does the neutral go?

    I'm wondering if I should connect the TB2 ground screw on my VFD to the chassis ground (which is connected to earth, green wire ground) and the neutral (white wire) to TB1 ground screw? The manual alludes that the ground on TB1 and TB2 are connected but does not directly state this.

    I'm wondering if I should not use my white wire at all and only go to chassis ground (green wire) on both TB1 and TB2? This seems super odd to me but is what the manual is directly dictating. I have NEVER wired 240V-1 phase without using the neutral. I would be depending on using my houses earth ground to support all of the power being delivered to my mill - which seems super odd.

    The confusion comes from Figure 2-2 on page 2-3 (page 15) and the discussion of motor wiring on page 2-6 (page 18).



    Dave
    Dave?

    The manual is not what is confusing. Your assumptions are.

    The illustration you cite shows a standard 3-Phase input on L0, L1, L2.

    You do not HAVE a 3-Phase source of supply for it

    The US residential/ smallholder distribution system is "split phase" single-phase in that the last transformer is 240 VAC center-tapped, and the tap is Earthed. The Neutral is what gives you a 120 V path from either "hot leg".

    Either "hot" is only HALF as great a potential above Earth. Risk of electrocution, US or Japan is much lower than most of the rest of the world where metal is expensive, and lives are much cheaper than Copper.

    Your VFD is not USING 120 V.

    There IS NO place to connect it. Anywhere. None ON the VFD.
    The neutral doesn't even have to leave the outlet's box at all.
    Change your cord to 2 Wire + Ground?
    Problem goes away entirely

    Same as when you left out the hot and cold water lines, compressed air, and the drain-waste-vent plumbing the VFD didn't need EITHER, yah?



    Is that "universal?"

    No.

    A 3-Phase "WYE" load device could want up to FIVE wire service, and use them all. I have some. 3-each Phase legs. Neutral. PE (Ground).

    But a VFD is "usually" a "Delta" device when fed 3-Phase. 3-each phase legs, PE (Ground), NO Neutral.

    WHEN a manual depicts three wires? Could it be you are looking at how it is meant to be wired WHEN ON 3-Phase feed?

    Just as surely as shit stinketh you are!



    ELSE a two-legged device (plus PE/Ground) when fed 240 VAC single-phase.

    I DID have, at one time a 120 VAC input VFD (Weg).

    But WHEN on such service? Still only 2 wires plus PE/Ground.

    In the 120 VAC case one conductor IS the "Neutral". And carrying current. Locally. "mostly". Which is WHY it is treated differently from ground once "inside" the service entrance point "corral" of your premises.

    And thereby supports the upstream grid retaining better means of serving its other priorities as to balancing.

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    Thanks for the reply.

    I have to admit, it's been 40 years since I learned about Y and Delta connections (and I may not have learned it then). I understand what you are saying though. I am still glad that I have a 4 wire connection to the wall, for I have also added a 4x4 box with two duplex 120V outlets. I am using this to power my X axis feed and a LED light.

    I have added a modified schematic of what I'll be changing on the mill. I programmed the VFD and it is operating correctly for direction and speed control with the potentiometer. I feel good about that. I'll remove the neutral from the VFD TB1 and go to the chassis (earth) ground. I currently have the TB2 ground at earth ground.

    Please look at the schematic and let me know if I understood what you are saying. I am still new to the forum and didn't notice that there was a forum specifically for VFD's. I posted the same topic there and got the same response as you gave.

    Thanks again for the help.

    Dave

    hardinge_tm_wiring_diagram_dave_p_vfd_modjpg.jpghardinge_tm_wiring_diagram_dave_p_vfd_modjpg.jpg

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    Quote Originally Posted by techymechy View Post
    Please look at the schematic and let me know if I understood what you are saying. I am still new to the forum and didn't notice that there was a forum specifically for VFD's. I posted the same topic there and got the same response as you gave.
    You would get the same. NFPA 70 thing.

    Does no good for ME to look, and how could I know WHAT you understand?

    I don't even use V Effing Dee's since reaching enlightenment.
    Scrapped my ones as a needless pain in the a**.

    RPC, Phase-Perfect, 3-P Diesel gen set, or DC Drives, rather.


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    Ya, it would be nice to have 3 phase power in the house, but that isn't what I have. Also, I'm new at this machining hobby so I want to take the investment in equipment a little slow until I know more.

    I have the VFD working fine. I need to mount the potentiometer now although it is working correctly.

    I was testing the VFD with my X axis Servo feed (I have a Servo model 50 on the X axis). I noticed that when I ran the mill motor, the servo motor ran significantly faster when I had it plugged into the two duplex sockets I added to the mill. I moved the power for the servo feed to the wall and the Servo feed only sped up a little bit when I turned on the mill motor. I measured the voltage at the sockets with my fluke DMM and the voltage did not change when I turned on/off the mill motor.

    I think I might be getting noise from the VFD feeding back into my electrical system. I'm assuming that the noise is high frequency for my VFD carrier frequency is 4 kHz. Would you add a ferrite beads to the power input line and the wires feeding my 4x4 duplex box?

    Dave

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    Quote Originally Posted by techymechy View Post
    I think I might be getting noise from the VFD feeding back into my electrical system. I'm assuming that the noise is high frequency for my VFD carrier frequency is 4 kHz. Would you add a ferrite beads to the power input line and the wires feeding my 4x4 duplex box?

    Dave
    Too much work to Engineer the proper ones. That isn't where a VFD is at its worst, anyway. DC drives hammer the input side. VFD hammer the output side.

    I added a trip to the recycling center by throwing-away the three VFD's, two bought brand-new, so as not to make the same mistake even once, instead.



    The Phase-Perfect has gotten all the filtering. Upline chokes & c. output-side TCi Sine-Guards, Delta-Wye transformer "etc".

    Only ONE to do, not one per-each machine's Vee Effing Dee.

    The RPC generates Harmonic Distortion, but it isn't all that bad, nor the sort to mess with the 'puters, routers, & c.

    My DC Drives got "drive Isolation" transformers and CORCOM's .

    Retired Telco & Data guy, "etc."

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    Thanks for the replies Thermite. I'll stop this thread and focus on the similar thread in the VFD specific forum.

    Not yet retired Thermal/Mechanical engineer.


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