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Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 12:03 pm
by mael
Hey guys.
I need your help. I have a 2.2kw spindle so it should be a 10amp 3phase motor. There should be about 3.33 amps per phase. Adding 30% more for safety margins gives me about 4.33amps per phase right? So using a AWG 20 wire should be more than enough right?
I also read that it is best to use wires that have shielding, however, good wires are hard to come by from where I am.
What i did on my previous build was wrap the entire length of the wire with aluminum tape (making sure that there was conductivity from both ends of the tape for grounding). But maybe I was being stupid and there wouldve been a better solution, like maybe audio cables or tv cables. What do you think?

Also, what is the best wire to use for the stepper motor? I have a 4amp per phase stepper (nema 34 8.5nm motors). What I found available here are those shielded wires but there are quite small. Im not sure if they can handle the amps. What is the minimum wire cross sectional area size should i use for this?

Thanks

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 2:36 pm
by cbb1962
I have a related question: I am connecting an integrated servo. It will have two sets of connections; Power and Control, (step, direction, enable and Alarm.) I will use 16 gauge for power, I was wondering if anyone had ever used stranded and shielded CAT 6a for control wiring? It claims: "Stranded cable for maximum flexibility." A friend of mine that is an EE and has built hundreds of panels suggested it.

Thanks!

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 3:17 pm
by martyscncgarage
mael wrote: Tue Feb 06, 2018 12:03 pm Hey guys.
I need your help. I have a 2.2kw spindle so it should be a 10amp 3phase motor. There should be about 3.33 amps per phase. Adding 30% more for safety margins gives me about 4.33amps per phase right? So using a AWG 20 wire should be more than enough right?
I also read that it is best to use wires that have shielding, however, good wires are hard to come by from where I am.
What i did on my previous build was wrap the entire length of the wire with aluminum tape (making sure that there was conductivity from both ends of the tape for grounding). But maybe I was being stupid and there wouldve been a better solution, like maybe audio cables or tv cables. What do you think?

Also, what is the best wire to use for the stepper motor? I have a 4amp per phase stepper (nema 34 8.5nm motors). What I found available here are those shielded wires but there are quite small. Im not sure if they can handle the amps. What is the minimum wire cross sectional area size should i use for this?

Thanks
Personally on an AC motor, I have not used shielded cable. I use 14/3 cord with a ground, or you may use aluminum flexible conduit or liquid tight conduit, with 3 #14 gauge wires and a ground.

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 3:21 pm
by martyscncgarage
cbb1962 wrote: Tue Feb 06, 2018 2:36 pm I have a related question: I am connecting an integrated servo. It will have two sets of connections; Power and Control, (step, direction, enable and Alarm.) I will use 16 gauge for power, I was wondering if anyone had ever used stranded and shielded CAT 6a for control wiring? It claims: "Stranded cable for maximum flexibility." A friend of mine that is an EE and has built hundreds of panels suggested it.

Thanks!
This is my .02...
For data signal wires I always try to use twisted pair shielded cable. Yes, I have used Cat6A stranded, shielded 23AWG cable for encoders and have had no problems to date. Read STRANDED wire, because of Axis movement.

I'm sure someone will chime in if this isn't good practice.....

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 6:09 pm
by mikes
mael wrote: Tue Feb 06, 2018 12:03 pm Hey guys.
I need your help. I have a 2.2kw spindle so it should be a 10amp 3phase motor. There should be about 3.33 amps per phase. Adding 30% more for safety margins gives me about 4.33amps per phase right? So using a AWG 20 wire should be more than enough right?
I also read that it is best to use wires that have shielding, however, good wires are hard to come by from where I am.
What i did on my previous build was wrap the entire length of the wire with aluminum tape (making sure that there was conductivity from both ends of the tape for grounding). But maybe I was being stupid and there wouldve been a better solution, like maybe audio cables or tv cables. What do you think?

Also, what is the best wire to use for the stepper motor? I have a 4amp per phase stepper (nema 34 8.5nm motors). What I found available here are those shielded wires but there are quite small. Im not sure if they can handle the amps. What is the minimum wire cross sectional area size should i use for this?

Thanks
What length do you need? I just got 100ft of some Belden VFD power cable 16/4 shielded and do not need it all. PM me if you are interested.

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 8:23 pm
by Reedfirst
mikes wrote: Tue Feb 06, 2018 6:09 pm
mael wrote: Tue Feb 06, 2018 12:03 pm Hey guys.
I need your help. I have a 2.2kw spindle so it should be a 10amp 3phase motor. There should be about 3.33 amps per phase. Adding 30% more for safety margins gives me about 4.33amps per phase right? So using a AWG 20 wire should be more than enough right?
I also read that it is best to use wires that have shielding, however, good wires are hard to come by from where I am.
What i did on my previous build was wrap the entire length of the wire with aluminum tape (making sure that there was conductivity from both ends of the tape for grounding). But maybe I was being stupid and there wouldve been a better solution, like maybe audio cables or tv cables. What do you think?

Also, what is the best wire to use for the stepper motor? I have a 4amp per phase stepper (nema 34 8.5nm motors). What I found available here are those shielded wires but there are quite small. Im not sure if they can handle the amps. What is the minimum wire cross sectional area size should i use for this?

Thanks
What length do you need? I just got 100ft of some Belden VFD power cable 16/4 shielded and do not need it all. PM me if you are interested.

I'm pretty sure you don't divide up the amperage by phase. I believe a 10 am 3 phase motor draws 10 amp per phase. Check the NEC code book to be sure. I assume no liability.....

Does 20awg really seem like the right size for 2.2kw? Almost 3hp......

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 8:33 pm
by cbb1962
Martyscncgarage wrote:
This is my .02...
For data signal wires I always try to use twisted pair shielded cable. Yes, I have used Cat6A stranded, shielded 23AWG cable for encoders and have had no problems to date. Read STRANDED wire, because of Axis movement.
Thank you, Sir! You are a gentleman and a scholar.

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 8:39 pm
by martyscncgarage
Reedfirst wrote: Tue Feb 06, 2018 8:23 pm
mikes wrote: Tue Feb 06, 2018 6:09 pm
mael wrote: Tue Feb 06, 2018 12:03 pm Hey guys.
I need your help. I have a 2.2kw spindle so it should be a 10amp 3phase motor. There should be about 3.33 amps per phase. Adding 30% more for safety margins gives me about 4.33amps per phase right? So using a AWG 20 wire should be more than enough right?
I also read that it is best to use wires that have shielding, however, good wires are hard to come by from where I am.
What i did on my previous build was wrap the entire length of the wire with aluminum tape (making sure that there was conductivity from both ends of the tape for grounding). But maybe I was being stupid and there wouldve been a better solution, like maybe audio cables or tv cables. What do you think?

Also, what is the best wire to use for the stepper motor? I have a 4amp per phase stepper (nema 34 8.5nm motors). What I found available here are those shielded wires but there are quite small. Im not sure if they can handle the amps. What is the minimum wire cross sectional area size should i use for this?

Thanks
What length do you need? I just got 100ft of some Belden VFD power cable 16/4 shielded and do not need it all. PM me if you are interested.

I'm pretty sure you don't divide up the amperage by phase. I believe a 10 am 3 phase motor draws 10 amp per phase. Check the NEC code book to be sure. I assume no liability.....

Does 20awg really seem like the right size for 2.2kw? Almost 3hp......
I would use no less than 14 awg. On 15a frnr fuses

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 9:18 pm
by cncman172
You can use 16 AWG wire fora 2.2 KW spindle. Do yourself a huge favor and use Beldon or other brand that has a braided shield. AC spindles and their VFD generate a huge amount of EMI that can cause interference issues with Acorn or other controls, very common issue. The control cable can be Ethernet cable that is shielded but wire size for analog output to VFD is sensitive so double wires for analog ground and analog output or you will experience motor variation if the cable is longer than five feet

Russ

Re: Question for acceptable wiring choice

Posted: Tue Feb 06, 2018 11:35 pm
by mael
cncman172 wrote: Tue Feb 06, 2018 9:18 pm You can use 16 AWG wire fora 2.2 KW spindle. Do yourself a huge favor and use Beldon or other brand that has a braided shield. AC spindles and their VFD generate a huge amount of EMI that can cause interference issues with Acorn or other controls, very common issue. The control cable can be Ethernet cable that is shielded but wire size for analog output to VFD is sensitive so double wires for analog ground and analog output or you will experience motor variation if the cable is longer than five feet

Russ
Thanks for this. By double you mean using an entire cat6 shielded cable on the + and another on the -? or half of wires in the cable?
using a cat6 wire for the Acorn to motor driver also is preferred right?