# Machine Wiring Help



## jbolt (Apr 13, 2014)

I am in the middle of a CNC conversion of a R45 clone mill. The mill came with power z-axis and a power table feed. I have moved the machine controls to another enclosure and have removed the motor contactors and switches for the z and table motors since I will no longer be using them. When I moved the controls and wiring I left most everything connected. Upon reconnecting the power I cannot get the motor contactor to energize. I'm pretty much out of my realm on chasing this down. I have 220vac to the contactor and transformer input. On the transformer output I get 13.9vac to terminal 31 and 6.2vac on terminal 30. If I understand the label correctly I think I should be getting 24vac at 30 & 31? Everything worked fine prior to disconnecting and reconnecting. Below are pictures of the original installation and the new enclosure installation. any help would be appreciated.

Jay


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## rdhem2 (Apr 13, 2014)

Before I could even start I would need an original wiring diagram.  My first thought is you opened a circuit for the "Z" axis that told the other ones it was fine.  You usually can not just remove wiring for one thing without affecting something else.  

Good luck, this one could be fun!


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## John Hasler (Apr 13, 2014)

jbolt said:


> I am in the middle of a CNC conversion of a R45 clone mill. The mill came with power z-axis and a power table feed. I have moved the machine controls to another enclosure and have removed the motor contactors and switches for the z and table motors since I will no longer be using them. When I moved the controls and wiring I left most everything connected. Upon reconnecting the power I cannot get the motor contactor to energize. I'm pretty much out of my realm on chasing this down. I have 220vac to the contactor and transformer input. On the transformer output I get 13.9vac to terminal 31 and 6.2vac on terminal 30. If I understand the label correctly I think I should be getting 24vac at 30 & 31? Everything worked fine prior to disconnecting and reconnecting. Below are pictures of the original installation and the new enclosure installation. any help would be appreciated.



You should have 24VAC between 30 & 31.  Unless the winding is grounded (it probably isn't) what you read from either terminal to ground is meaningless.

I can't tell anything useful from the pictures.  Sorry.


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## jbolt (Apr 13, 2014)

Here is the wiring schematic from the manual.


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## JimDawson (Apr 13, 2014)

Based on the voltages read from 30 and 31 is seems that you are measuring to ground.  You should find 24VAC across 30 and 31 and not referenced to ground.

I'll look at the schematic  and see if I can see anything.

Best of luck.

EDIT:

From the schematic that Jbolt posted, it looks like one side of the 24VAC should be grounded, this would be normal.  The other side should go to wire 1, then through the breaker, and exits the breaker as wire 3.  Follow the schematic through with your volt meter and see at what point you lose power.


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## jbolt (Apr 13, 2014)

JimDawson said:


> Based on the voltages read from 30 and 31 is seems that you are measuring to ground.  You should find 24VAC across 30 and 31 and not referenced to ground.
> 
> I'll look at the schematic  and see if I can see anything.
> 
> Best of luck.



Okay I get 27vac across 30 and 31.

Jay


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## John Hasler (Apr 13, 2014)

jbolt said:


> Okay I get 27vac across 30 and 31.
> 
> Jay



That's close enough. Have you checked the fuse?


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## jbolt (Apr 13, 2014)

John Hasler said:


> That's close enough. Have you checked the fuse?



Fuse is good.


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## chip_slinger (Apr 14, 2014)

Are both estops disengaged?



jbolt said:


> Fuse is good.


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## jbolt (Apr 14, 2014)

chip_slinger said:


> Are both estops disengaged?



Both? There is only one e-stop.


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## chip_slinger (Apr 14, 2014)

SB1 and SB3 are shown as normally closed estops. Can you take a picture straight on of the button wiring and terminals? And of the button themselves from the front?



jbolt said:


> Both? There is only one e-stop.


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## jbolt (Apr 14, 2014)

chip_slinger said:


> SB1 and SB3 are shown as normally closed estops. Can you take a picture straight on of the button wiring and terminals? And of the button themselves from the front?



SB1 is the e-stop (1st photo right), SB2 is the green start button (1st photo middle), SB3 is the red stop button (1st photo left)


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## chip_slinger (Apr 14, 2014)

I can trace through SB2 and it all looks right, but it's hard to see the wiring on SB3. Coming off of SB3 on the lower left terminals you should have two wires; one will go to the green light and the other will go to the coil terminal on the contactor (lowest two terminals, near the colored plug showing the coil voltage of 24VAC). The other coil terminal should go to ground. Can you trace that part of the circuit and see if it is correct? It also looks like there is a wire going to one of the upper terminals on SB3?



jbolt said:


> SB1 is the e-stop (1st photo right), SB2 is the green start button (1st photo middle), SB3 is the red stop button (1st photo left)


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## JimDawson (Apr 14, 2014)

It looks like one side of the 24VAC should be grounded, this would be normal. The other side should go to wire 1, then through the breaker, and exits the breaker as wire 3. Follow the schematic through with your volt meter and see at what point you lose power.

With one voltmeter probe on the common terminal of the transformer, 30 or 31, I can't tell from the pictures, the wire may be labeled 2.  With the green button pressed, you should have 24VAC on wire 9, and at terminal A1 of KM1.  Terminal A2 on KM1 should be directly connected to the common terminal of the transformer.

If you don't have 24VAC on wire 9 then check at wire 5.


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## jbolt (Apr 14, 2014)

chip_slinger said:


> I can trace through SB2 and it all looks right, but it's hard to see the wiring on SB3. Coming off of SB3 on the lower left terminals you should have two wires; one will go to the green light and the other will go to the coil terminal on the contactor (lowest two terminals, near the colored plug showing the coil voltage of 24VAC). The other coil terminal should go to ground. Can you trace that part of the circuit and see if it is correct? It also looks like there is a wire going to one of the upper terminals on SB3?



There are two red wires off the left side of SB3, one to the green light the other to the lower left bottom terminal on the contactor KM1. On the lower right upper terminal of KM1 there are two blue wires, one goes the the green light and the other goes to terminal 30 of the transformer.  

Hope that makes sense.

Jay


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## JimDawson (Apr 14, 2014)

jbolt said:


> There are two red wires off the left side of SB3, one to the green light the other to the lower left bottom terminal on the contactor KM1. On the lower right upper terminal of KM1 there are two blue wires, one goes the the green light and the other goes to terminal 30 of the transformer.
> 
> Hope that makes sense.
> 
> Jay




The blue wire is the 24VAC common.  wire 009 should go to the lower left bottom terminal on KM1, this terminal should be labeled A1 or A2


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## jbolt (Apr 14, 2014)

Thanks for everyone's help so far. I have to call it a night. Tomorrow I will make a sketch of the wiring and see if that helps clear things up.

Jay


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## jbolt (Apr 14, 2014)

JimDawson said:


> The blue wire is the 24VAC common.  wire 009 should go to the lower left bottom terminal on KM1, this terminal should be labeled A1 or A2



Wire 009 goes to A1. The blue wire goes to A2. With the green button pressed I get 24vac on wire 009 at A1.

Jay


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## JimDawson (Apr 14, 2014)

jbolt said:


> Wire 009 goes to A1. The blue wire goes to A2. With the green button pressed I get 24vac on wire 009 at A1.
> 
> Jay



OK, that's great.

Is the blue wire connected to the transformer?

Does the green light come on when you push the green button? 

With the green button pushed, do you have 24VAC between A1 and A2 on KM1?

If all of the above are true, then the contactor armature is probably jammed.  This is not an uncommon problem on Chinese contactors.  With power disconnected from the machine.  Loosen the contact block mounting screws a bit, and wiggle it a bit while testing the armature freedom by pushing the little black button on the contactor face.  Re-tighten the screws when thing are aligned properly.


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## jbolt (Apr 14, 2014)

I wiil check that out tonight. I'm beginning to better understand how the switch circuit works. I'm suspecting it may be the 24vac common connection at A2. I replaced this wire with a longer lead and the spade connectors are a little wide so I may not have it seated properly.  I need to pick ip some longer test leads to better reach the coil terminals. 

Jay


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## jbolt (Apr 14, 2014)

Okay I found it. Turned out to be the 24vac connection at terminal 30 on the transformer not being seated correctly. You cant see the terminal pocket without a mirror so it wasn't getting clamped even though it felt tight. Everything now works as it should. 

Thanks for everyones help. In a way i'm glad this happened as I now have a better understanding of how the motor control and switching works and how to troubleshoot.

Thanks again. 

Jay


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## chip_slinger (Apr 14, 2014)

Glad you got it all sorted out. 



jbolt said:


> Okay I found it. Turned out to be the 24vac connection at terminal 30 on the transformer not being seated correctly. You cant see the terminal pocket without a mirror so it wasn't getting clamped even though it felt tight. Everything now works as it should.
> 
> Thanks for everyones help. In a way i'm glad this happened as I now have a better understanding of how the motor control and switching works and how to troubleshoot.
> 
> ...


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## jbolt (Apr 15, 2014)

I have another question. I have (2) extra contactors so I was thinking I could use these to power up the stepper motor power supplies. I have (2) 115amp 110vac lines to power the steppers, coolant pump and PS for the breakout board. The contactors are rated at 20A. What would be the best way to wire these to the same switch circuit?

Jay


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## JimDawson (Apr 15, 2014)

jbolt said:


> I have another question. I have (2) extra contactors so I was thinking I could use these to power up the stepper motor power supplies. I have (2) 115amp 110vac lines to power the steppers, coolant pump and PS for the breakout board. The contactors are rated at 20A. What would be the best way to wire these to the same switch circuit?
> 
> Jay




Would you lay out all of the components (switches, relays, step drives, etc.) that you have to work with on a table and take a picture of them.  I need to see exactly what you have to help you make everything work together.

In general, you want to have a Control Power Relay that powers up the control voltage to run the rest of the system.  This relay can also power up the the step motor power supply(s).  Normally I use only one step motor power supply to power up all of the step motor drives.  This really depends on what hardware you have.


Below is a picture of a control panel I built to run a 4 axis router.  The heavy power stuff on the right is to run the 10HP spindle VFD and the 5HP vacuum pump.  There is a fused disconnect on top of the box that powers up the whole system.  In the center, the black and blue things are the 70VDC power supply for the step drives.  The control circuitry is all on the left.  The step drives are left, near center.  This is to give an idea of what needs to go into the system to have full, and safe control over the machine.  The switches for the controls are in another box.  Normally I would have used a bigger enclosure for the build, but this is what I had to work with, it's a bit crowded.


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## jbolt (Apr 15, 2014)

Jom, i cannot layout all my component as they are mostly installed in enclosures. Each stepper, xyz&a have their own PS and driver. Im splitting the load between two 15A circuits. I was thinking since I have the extra relays I could use them to power up the whole system with one start button plus it would all be on the same estop as well. 

To start/stop three relays with one switch corcuit would the coils be wired in parallel and the holding circuit wired in series?

Jay


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## JimDawson (Apr 15, 2014)

jbolt said:


> Jom, i cannot layout all my component as they are mostly installed in enclosures. Each stepper, xyz&a have their own PS and driver. Im splitting the load between two 15A circuits. I was thinking since I have the extra relays I could use them to power up the whole system with one start button plus it would all be on the same estop as well.
> 
> To start/stop three relays with one switch corcuit would the coils be wired in parallel and the holding circuit wired in series?
> 
> Jay



Please be very careful feeding from 2 separate 120 circuits, they could be connected to opposite sides of the breaker panel and thus would have 240 VAC between them.  You can check this by putting a volt meter between the 2 hot legs on the plugs (the small lug of the plug if it is wired correctly).  If they are the same phase, the reading on the meter should be near zero, if not you will have around 240V.  Things can get ugly in a hurry if you are connected to opposite phases and don't have proper isolation.

Yes, you can power up everything in the way you described.  It looks like you have terminals 43 and 44 available on KM1 to power up the other 2 relays.  This will make KM1 the control power relay, thus when you hit the E-stop everything will power down.  

Connect 24VAC to terminal 43 and connect 44 to A1 on the other 2 relays, connect A2 on the relays to the 24VAC common.  You could add a couple of switches between 44 and A1 on the 2 relays, this would allow you to turn off the devices connected to those relays if you don't need them for what you are doing at the time.


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## jbolt (Apr 15, 2014)

Thanks Jim. As as contractor for 30 years I am quite familiar with residential wiring. Electronics not as much but i try to be careful. 

Jay


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## John Hasler (Apr 15, 2014)

jbolt said:


> Im splitting the load between two 15A circuits.
> 
> Jay



If you do that handle-tie the two breakers.  Best would be to use a 15A two pole breaker.


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## JimDawson (Apr 15, 2014)

jbolt said:


> Thanks Jim. As as contractor for 30 years I am quite familiar with residential wiring. Electronics not as much but i try to be careful.
> 
> Jay




You're welcome.  Sounds like you have it under control.  You never know what the skill level is of the person on the other end of the thread.  Glad I could be of some help.  If you get stuck, you can always shoot me an email or a PM if I don't respond here.


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