2 Attachment(s)
Spindle not grounded - problem with motor - is it related ?
Hello guys,
I have a question for skilled ones in electricity since I do not understand it. I had accident and would
like to know if it could be happen by switching spindle for ungrounded one.
I have two spindles 2,2kw water cooled. Old one and new one. Both are casual chinese versions.
I was not satisfied with sound of bearings of new one which I used for 1,5 year. So I
grabbed old setup I had aside and installed it. I used it for three days without problem, but
suddenly Motor on my Z stopped work. I measured power supply, it was ok. I tried cables from other motors,
still same. On support they told me to send it to RMA. So I did. I was thinking about if it is somehow related
with change of spindle. So I checked wiring, because it is old spindle from time when I started to build DIY machine
and understand to nothing. In that time I used it for 2 years without problem. What I found out, that spindle is not grounded and also on Huanyang VFD I had not connected grounding from spindle
to power cable and had switched grounding with negative. I add photo. So my question is:
1. Is it possible that motor could be damaged because spindle was not grounded, or
it should be just bad coincidence that happen in similar time ? (Spindle is connected just to VFD, not further like control board...)
2. Can someone please check the correction of VFD connection if it is right now how I marked ? (Ignore the yellow/green cable, it is really position 3 on spindle, I do not want to do resolder it) *
thank you
Re: Spindle not grounded - problem with motor - is it related ?
If the old one worked perfectly for two years, I guess it must be the new motor problem.
2 Attachment(s)
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
Arche
Hello guys,
I have a question for skilled ones in electricity since I do not understand it. I had accident and would
like to know if it could be happen by switching spindle for ungrounded one.
I have two spindles 2,2kw water cooled. Old one and new one. Both are casual chinese versions.
I was not satisfied with sound of bearings of new one which I used for 1,5 year. So I
grabbed old setup I had aside and installed it. I used it for three days without problem, but
suddenly Motor on my Z stopped work. I measured power supply, it was ok. I tried cables from other motors,
still same. On support they told me to send it to RMA. So I did. I was thinking about if it is somehow related
with change of spindle. So I checked wiring, because it is old spindle from time when I started to build DIY machine
and understand to nothing. In that time I used it for 2 years without problem. What I found out, that spindle is not grounded and also on Huanyang VFD I had not connected grounding from spindle
to power cable and had switched grounding with negative. I add photo. So my question is:
1. Is it possible that motor could be damaged because spindle was not grounded, or
it should be just bad coincidence that happen in similar time ? (Spindle is connected just to VFD, not further like control board...)
2. Can someone please check the correction of VFD connection if it is right now how I marked ? (Ignore the yellow/green cable, it is really position 3 on spindle, I do not want to do resolder it) *
thank you
I'm surprised that you got that much running out of it wired like you have, it is very unsafe to run these spindles without a Ground, not only will it shorten the life of the Bearings in the Spindle, but the safety factor is also very high, every Spindle needs to be check for Ground 90% of the Spindles sold, don't have the Ground connected, in China, it is called population control
R S T are all Input Power Connections, for 3Phase / Single Phase only uses R / T plus Ground ?
If you are using Single Phase power supply, then the correct connections are for the input power, can only be R / T and Ground so the Hot (live) wire to (R) the Neutral to (T) the Ground / Earth ? to the Ground Terminal ?
You must use the correct wire colors, or use heat shrink tubing to change the wire color.
With the wiring like you have it, the VFD Drive may be damaged as the Input power wiring is incorrect.
The Spindle wiring / Cable needs to be 4 wire Shielded Cable (3) Hot / live wires (1) Ground ? Plus Shield
Wiring of the Spindle Plug
Pin=1=U
Pin2=V
Pin3=W
Pin4=Gnd ? (Ground)
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
cncmakers001
If the old one worked perfectly for two years, I guess it must be the new motor problem.
There may be a motor problem, that is easy to check, but wiring and Safety is the first problem
1 Attachment(s)
Re: Spindle not grounded - problem with motor - is it related ?
Hello mactec54,
thank you for description and advices. I know that it is pain to look into it for
someone who understand it. Anyway I did some corrections about wiring. I have two setups of VFD-Spindles, both are
a little bit different brand. According to your description only one connection is matching. I add schema picture.
The first one should be alright. The second one according to the description is wrong. Anyway both setups works, spindles
are spinning. I am little bit confused that ground mark on second VFD is under letter R, on first schema is for phase.
I did the connection from someones video on youtube, but dunno if he used single or three phases input and if there is some difference then.
I use single phase input.
So should I correct second schema with:
T *to *R
S *to *T
GND to S or straight to spindle GND ?
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
Arche
Hello mactec54,
thank you for description and advices. I know that it is pain to look into it for
someone who understand it. Anyway I did some corrections about wiring. I have two setups of VFD-Spindles, both are
a little bit different brand. According to your description only one connection is matching. I add schema picture.
The first one should be alright. The second one according to the description is wrong. Anyway both setups works, spindles
are spinning. I am little bit confused that ground mark on second VFD is under letter R, on first schema is for phase.
I did the connection from someones video on youtube, but dunno if he used single or three phases input and if there is some difference then.
I use single phase input.
So should I correct second schema with:
T *to *R
S *to *T
GND to S or straight to spindle GND ?
The first diagram will work, R / T plus Ground No other connection is possible
If you connect Ground to R you will have a dead short this is very bad
Do not look at Videos most are incorrect
R S T are Power connections Only, the VFD Ground is the last Terminal on the Right check if it has the Ground symbol
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
servtech
A split 2 phase AC motor needs two phases and direction controlled by the drive or a starter. If you use RS,ST or RT phase connections, you only change motor polarity and direction.
Personally, I would only connect the phases I need for the machine, I wouldn't use the third phase if not required, it could be a safety issue.
Why are you posting about 2 Phase get with the program if you don't understand what is being used don't post this Bs it is only confusing for the OP
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
servtech
3 phase motors are generally wired star or delta.
Star needs a neutral and ground. RST N and Ground
.
Who's motors are you using where the Star connection requires a neutral??? :confused:
Re: Spindle not grounded - problem with motor - is it related ?
Three phase Star connected Motors don’t require a neutral line because there is no need even in a Y-connected motor with a common point, because the 3ph motor is an inherently balanced load,
i.e. each phase has the same number of windings and wire size.
So no matter how much load is on the rotor/shaft. There is no need for a neutral because all the power that goes in one phase goes equally out the other two for all three phases.
There should always be a Earth-GND for safety and protective purposes, but that does not require the presence of a neutral.
If it is there, it is superfluous!
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
servtech
Just explain to me why neutral is needed and why the hundreds of thousands of motors out there are running without it.?
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
servtech
There is only two phases connected to that drive he posted. I was stating motor theory.
Theory does not cut it, correct posting is important
There is no such thing as two-phase power, supply being connected to any VFD Drive
He is using Single-phase power supply, probably 230v (1) Hot (live) / Neutral Plus Ground (Earth)
3 Attachment(s)
Re: Spindle not grounded - problem with motor - is it related ?
Hello guys,
there is so many informations I do not understand and are out of topic. What
nobody mentioned if it is possible, when spindle was not grounded, could it be possible
that could destroy motor on Z axis through metal frame of machine ?
I also found original message from supplier of spindle:
--------------------
Dear friend,
Connect "R" and "T" (at the invert-er) to the single phase power supply.You could also connect "R" and "S" or "S" and "T".Both ways are OK.
If you use it with three phase input,connect the three phase power supply to "R, S T",
and then connect the "U, V, W " to the motor 1, 2, 3(U to 1, V to 2, W to 3).
Number 4 is for earth.You can either connect earth or not.Usually, we don't connect earth )))
--------------------
So no wonder that so many variation of connection worked for me.
Anyway I add some pictures.
1: picture symbols: So I explain it, that this left ground mark is just coincidence when someone did plastic injection
and mirrored model with symbol from right side ? So it should not be there ?
2. picture video: This is print screen from video, some guy did this connection, like me, so it works but it is not right and ideal ?
3. picture VFD3: *Please check it if I did correct connection, where grounding goes directly from spindle to power cord 230V.
* * * * * * * * * So from power cord I connect only R, T and grounding from spindle goes to earth wire.
thank you
1 Attachment(s)
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
Arche
Hello guys,
there is so many informations I do not understand and are out of topic. What
nobody mentioned if it is possible, when spindle was not grounded, could it be possible
that could destroy motor on Z axis through metal frame of machine ?
I also found original message from supplier of spindle:
--------------------
Dear friend,
Connect "R" and "T" (at the invert-er) to the single phase power supply.You could also connect "R" and "S" or "S" and "T".Both ways are OK.
If you use it with three phase input,connect the three phase power supply to "R, S T",
and then connect the "U, V, W " to the motor 1, 2, 3(U to 1, V to 2, W to 3).
Number 4 is for earth.You can either connect earth or not.Usually, we don't connect earth )))
--------------------
So no wonder that so many variation of connection worked for me.
Anyway I add some pictures.
1: picture symbols: So I explain it, that this left ground mark is just coincidence when someone did plastic injection
and mirrored model with symbol from right side ? So it should not be there ?
2. picture video: This is print screen from video, some guy did this connection, like me, so it works but it is not right and ideal ?
3. picture VFD3: *Please check it if I did correct connection, where grounding goes directly from spindle to power cord 230V.
* * * * * * * * * So from power cord I connect only R, T and grounding from spindle goes to earth wire.
thank you
The VFD Drive Photo has the Ground symbol next to a screw in the case that is can be a Grounding point, not the R terminal above it, is only a Power Connection
So, with a Meter you can check the screws on the plastic case and Terminal #9 to see if the (2) screws have continuity with Terminal #9, if not then you can only use the #9 Terminal for Ground / Earth connection
The reseller does not know the correct VFD Drive connections Input Power for your VFD Drive is R / T plus Ground / Earth, there are no other connections if you followed what he said you would have a big problem
Both the Input Power and the Spindle Ground / Earth wire need to be connected to Terminal #9 on the VFD Drive
If you don't understand this wiring, you should get an electrician to help
Re: Spindle not grounded - problem with motor - is it related ?
Hello mactec54,
I measured with multimeter and there is no continuity between terminal 9 and screws, or between screws. They are just holding this peace of
electronic together. Electricians I know, frankly, they are just always guessing.
According my last posted connection schema picture VFD3, is it OK like that ?
1 Attachment(s)
Re: Spindle not grounded - problem with motor - is it related ?
Quote:
Originally Posted by
Arche
Hello mactec54,
I measured with multimeter and there is no continuity between terminal 9 and screws, or between screws. They are just holding this peace of
electronic together. Electricians I know, frankly, they are just always guessing.
According my last posted connection schema picture VFD3, is it OK like that ?
The VFD Drive must be Grounded so your schema picture is not quite right wire as my attached photo R =Hot / live T=Neutral and Ground / Earth to the #9 Terminal
Ok then the #9 Ground screw is what you have to use.
no electrician should be guessing confused:
Here is how you should be wiring your VFD Drive, for others that view this not all VFD Drives are wired the same
