Huanyang 220V 2.2kW VFD grounding and EMI issues

I am having some difficulty getting a Huanyang VFD and spindle motor to work properly and I’m hoping for some assistance. So far, I have destroyed two VFD’s and want to try again but need to make sure it works this time. It is a 220V, 2.2kW model HY02D223B purchased from Amazon June 2022.
The initial set-up had a 3-conductor 220V supply power and was configured as shown below

I received the spindle motor and VFD before the rest of the CNC machine and was able to set-up and successfully run this portion of the system. The VFD and motor worked great. The motor speed was controlled using the potentiometer on front of the VFD had no apparent issues.
The problem arose when everything was set up on my Onefinity CNC and there was so much EMI that I could not operate the machines touchscreen. Note that the VFD and CNC control were not electrically connected at all. The EMI problem went away when the motor was shut off, and there seemed to be some static electricity build up on the motor housing when it ran. Given that, it seemed like a ground issue so I decided to test this by temporarily attaching a ground wire to the motor housing, as shown below. When I did this the EMI issue went away, however after letting it run this way for about 15-30 seconds, I simply touched the motor housing with my hand and the VFD immediately exploded with a bright flash and popping sound. Not sure if the problem was due to me providing a parallel path to ground or if there was something wrong with my temporary wiring.

It was at this point that I thought perhaps this would benefit from properly rewiring the power supply to replace the 3-conductor romex with 4-conductor. I noticed that the 120V version of the Huanyang VFD called for the neutral to be connected to the “T” terminal. When I got my replacement VFD, I tested this and everything seemed to work so I went ahead and rewired everything.

In addition to adding the separate ground wire, I soldered a ground wire to the motor connector itself

With the rewiring complete I turned on the VFD with no issues, however as soon as the motor was turnedon the VFD instantly exploded in the same manner as before.

I went back through all my wiring and checked to make sure that there wasn’t some other error, but I couldn’t find anything wrong. I also checked the resistance values between the leads and the were as follows:

1 → 2 = 1.3 Ω
1 → 3 = 1.3 Ω
2 → 3 = 1.3 Ω
Pin 4 (ground) is isolated from the other three

It seems to me that everything was wired properly so I’m not sure what else to do. Any help/insight would be much appreciated since I cannot think of what could be done differently. (I have more pictures and wire diagrams but it would only let me post one)

CorvetteGuy50 on YouTube goes into great detail on grounding. If you haven’t watched his videos on that topic, its highly recommended. He details ways to test and reasons it may or may not be grounded properly.

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oh yes I am familiar with CorvetteGuy50. I may have to go back and re-review some of his posts…

Here is the how I wired the VFD using 4 conductors.

Hey Jeremy,

if you are in North America it is likely that you have Split-phase electric power which means you have 120 V between one hot and neutral and 240 V between to hots of different phases. So if you want to attach a VFD for 200-V-class single-phase input, you connect it between two hots of different phases. The neutral has nothing to do here! Your image Nr. 2 is extremely wrong! Don’t experiment with this if you do not know what you are doing. And Image Nr. 1 is lacking the ground between spindle and VFD (which you added correctly in Image 2 as the green line, but this is not shield! Please understand that the PE wire (Protective Earth) is mandatory (all the way through from spindle to ground on VFD, and then to ground contact on wall outlet!), and that PE and shield are something different (even if they are both connected to ground)! A shield does not replace a sufficiently dimensioned PE wire!

Please read the VFD manual and the spindle manual and follow the instructions exactly, and ask an experienced electrician or electrical engineer before attempting this.

Also I would not recommend to try to wire a spindle to a VFD yourself without having read this:

As for ground, it is dangerous to omit correct grounding.

Sorry, have not much time, got to go!


Image 1: A typical spindle cable for use in a power chain: Shielded 3+PE cable for a three phase spindle. Cables especially made for drag chains are e. g. LAPP ÖLFLEX® CLASSIC FD 810 CY (shown in the image above) or IGUS chainflex® . So far for the cable from VFD to spindle.

And now for the input of the VFD, read your VFD manual:

Symbol     Function Description
R, S, T   Input terminal of AC line power.
          (220V class, for both single/three phase,
          **single phase connected to any two phases**)

This means between the wall outlet and the VFD, you need a 2+PE cable and you wire it to only two of R,S,T (and PE wire from ground on wall outlet to ground on VFD). Neutral has nothing to do here, if it’s a 200 V class VFD model and you have split-phase electricity in your house! And the third contact on input is left unconnected here! (Note that R,S,T are only used all three if you also have three-phase electricity in your house, which is unlikely in North America).

But not with the 220 Volt model!!

Hey really got to go now, it’s 1:59 am in Central Europe :wink:

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Thank you so much for the feedback. If I’m understanding you correctly the diagram should look more like this.

Unfortunately this is exactly how I had when the EMI issue first appeared and I hooked up the temporary ground which caused the VFD to explode. I’m hesitant to try this again

And yes you are right on the 120V version the neutral is connect to T which is why it could make sense to do it that way on 220V as well. The manual is not very clear to me. It seems They should have just created a simple wire diagram and taken a lot of the guess work out. Also the fact that people have to go in and solder their own ground wire in there seems less-than-ideal.

By the way I am using the Igus wire you mentioned. Thanks again for all your feedback!

Hey Jeremy,

no, this is wrong! As I already explained, the neutral has nothing to do here! Omit any wiring to neutral, but connect all ground together, everywhere! The rightmost terminal of the VFD, in your image, this is the ground symbol (⏚), please connect it to the rest of your green wiring! And omit any wiring of neutral!

This is only correct for the 120 V model, but totally wrong with a 240 V model! As explained above, a 240 V model is connected between to hots of different phases, and neutral has nothing to do here!

This is the usual manual crap of cheap chinese VFDs. If you want a good VFD manual, buy a Omron MX2 or a Hitachi WJ200 and then you have a good manual!

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Sorry to keep you up, but really do appreciate it!

If I’m hearing you correctly now, what you are saying is simply go back to 3-conductor and tie everything to that.

I’m thinking you might be right about going to a higher quality VFD!

Hey Jeremy,

this is correct now with the green wire to the VFD, but you show the green connected to neutral now, but you have to connect it to PE (green/yellow). Connecting it to N would only be correct if you had no separate PE/ground which would be the case if you had a TN-C system. But in your first image, you seem to have the usual separate PE and N (a TN−S system). If this is the case, please, don’t connect your green ground to N, but to PE!

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In North America, if the duplex breaker is in the Main panel (not a sub panel), then the Neutral bus and the Grounded bus are bonded together. This tends to confuses some people. But yes, the white Neutral conductors should not be used and should not be connected to anything in a “220V” circuit (actually 240V as you note).

The green Equipment Grounding Conductor should be connected to cable shields, ground terminals, and all metal components of the system, both for EMI and safety reasons.

Former licensed electrician here… Key point here is to never connect the neutral (grounded conductor) and the bare/green ground (grounding conductor) together anywhere in branch wiring.

Second key point - the only electrical advice you should take from the internet is to hire a professional.

The grounded and grounding conductors are bonded together in the ‘service equipment’ which is basically the first overcurrent protection device at the service entrance to the building. This may or may not be in your circuit breaker panel, it could be outside located near the electrical meter. From that point on the grounding and grounded conductors must remain separate. There are many reasons for this all related to safety, in failure modes the last thing you want is the grounding conductors of the building becoming energized. This would also defeat the purpose of isolation switches installed when local generation systems are in use allowing electrical potential to energize the power grid presenting a hazard to linemen working to restore power (I realize they will treat everything as energized and will bond conductors to ground etc but don’t do it)


Thank you guys so much for your insights, really do appreciate it.

I’m in the process of reaching out to HY to see what they say. Since this motor did not come with a means of grounding it that’s an issue right there. If they still feel like this should work then I will have to get an electrician to take a look. For now I’m just using the Makita… I’ll let you know how it turns out.

Hey Jeremy,

good afternoon. Now your image corresponds to what I described yesterday (with the exception that I cannot see how you connected the cable shield, but for this you can read this paper).

It is important to understand that if you are not an electrician or an electrical engineer, you should only attempt to wire such things yourself if you are sure you have acquired at least the relevant knowledge of an electrician needed for this. This is not done by watching the amazon video that you can acquire this knowledge! Better if you want to get into the electrical subject is to buy the books that are used in the electrician’s apprenticeship.

But it was clear that you are someone who just does dangerous things and I have seen that you just connect cables somewhere without knowing what you are doing, and I could not have slept peacefully last night without having at least made clear the things mentioned above, because I knew you would just continue and I do not want to hear the next morning that you have burned your place down or were electrocuted.

I hope that you also did some other things right with cable assembling by using the correct crimped ring connectors or wire ferrules, and also by choosing adequate wire sizes.

I also hope that you did not program your VFD with settings you don’t understand just because someone on the net told you so, or just by following some amazon video, but made sure all mandatory VFD settings are set and correct.

If you search this forum you will find that your topic was asked and replied to many times already and most of the information is already there, as I mentioned above:

I hope you found success with HY support.

I want to point out that when you said the motor didn’t come with a means of grounding, that is in error. It comes with a 4 pin connector on the motor. Pin 4 as you show on diagrams is the protective ground.

All you need to do is join the cable shield and wire 4 on that one pin. Both PE and shield then attach to the ground screw on the VFD and on the same screw which goes to your outlet/panel ground.

The other more challenging way to attach the shield to the aviation connector is by carefully stripping everything to millimeter accuracy and clamping the bare shield under the half clip that secures the cable while connecting the 3 hot wires, but this is a weaker mechanical connection, but a 360 degree shield. This uses the metal body of the plug to tie the spindle body to the cable shield. Ideally the plug assembly is swapped out for a larger plug with a grounding gland included. I don’t recommend novice try this.

I hope on spindle #1 you didn’t drive a screw randomly into the body trying to ground it, that would explain sparks.

Also, don’t use your hand to verify 220 circuit operations. May be the last thing you do.

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Hey Warren @Cryptonym, hey Jeremy, hey all,

also it should be noted that some cheap chinese spindles come with a 4-pin connector, but the fourth (PE) pin is not connected to spindle housing internally! This can be verified with a multimeter set to ohms by checking between pin 4 and the spindle housing. In the case there is no connection, this should definitely be made up, as shown here

PS: When I see how thin the cables are, I feel really sick :cold_sweat:

I don’t have the HY spindle, but I’ve seen reports that pin 4 is unconnected inside the spindle. Sounds dangerous to me. Would be easy to check with an ohmmeter. Apparently some people open up the spindle and attach pin 4 to some convenient screw.

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Hey Warren,

In fact these “aviation” connectors found on cheap chinese spindles are no power connectors, I always wonder how they get the spindle cables into it.

Thanks for explaining how you managed this.

I am glad that the connector of my spindle is a Phoenix M17. It suits 1/2″ thick cables like the LAPP ÖLFLEX® CLASSIC FD 810 CY or IGUS chainflex® in shielded 4 x 2.5 mm² (~13 AWG/4) gauge, and the contacts are crimped :slight_smile:.

I totally agree with you, that’s why I always recommend these nice Spindle cables for chinese spindle/VFD kits, ready to use. They obviously use heat shrink tube to strengthen the mechanical connection / strain relief

When I think how many people try to solder these “aviation” connectors and it’s the first time they solder, it makes me feel sick, and when I think they also may have the PE pin not connected inside the spindle :frowning:

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Agree, though I’ve not heard of recent HY spindles not having pin 4 internally wired. Rattmotor, GPenny, can’t say the same for those.

As to wire size, they only have like 8 amps max on them with being 3 phase, the duty cycle and phasing lowers that number substantially.

…but, yet another reason to have rock solid grounding in place.

Pretty common issue it seems. I think HY has been putting grounds in for quite a while, but always worth a sanity check with a multimeter before plugging it in. If nothing else, it means the 7 year old Chinese kid assembling it soldered ground to pin 4 and not a hot pin.

LOL, I started soldering about 50 years ago, and yes, those “solder cup” connections on those connectors are not an easy thing for a beginner to start with.

Hey Barry,

I also began as a child. As soon as you have a soldering iron that your parents bought you, you soon learn there is something that tells you your soldering iron is but poor, and sticks it to the soldering point on the pcb. Hah! That’s it, the nasty evil, inconspicuous but apparently all heat absorbing ground. From then on you know, with anything under 80 watts you’re not really prepared for things in life :slight_smile: