[mountaindew]

Follow up!
I talked to tech support and they did not see a problem with changing the power cord to a 4 wire with a dedicated ground.
I will be more comfortable with it having a dedicated ground. Minor issue that will take very little time to customize.
In my opinion when mixing 2 of my favorite things high power and liquids there could be a potential problem.

Lots of fun, setting up mill and using the machine wizards and lots of scrap wood I have from the crate.
Learning and enjoying every minute so far.


md

ps: I'm new to cnc machines but not new to tools and equipment, and I can say this machine has a very acceptable level of quality for the price.
I un-crated, set and assembled it with options alone and with no problems at all. Cleaning parts takes a little time but with care and workman like manor it went together tight.

[MichaelHenry]

It's been a few years since I wired up my mill, but 220 VAC single-phase machines usually have 3 wires - 2 hot and one ground. Did your mill have some other arrangement?

It sounds like you the 4th wire you want would be neutral, rather than ground.

[mountaindew]

It's been a few years since I wired up my mill, but 220 VAC single-phase machines usually have 3 wires - 2 hot and one ground. Did your mill have some other arrangement?

It sounds like you the 4th wire you want would be neutral, rather than ground.

The machine is wired with 2 hot legs and a green ground per their drawings and design. Most modern 240v appliances now have 2 hot legs, 1 neutral and 1 ground dedicated. The reason I do not fully understand but it has to do with potential hence the pun in previous post.

I also found a tech bulletin that was issued with the machine documents that details a need for good machine grounding, not that it detailed how to do it.
And Tech support said connecting to the existing ground bus and to any dedicated 4th wire ground my home has would be a very good idea.

fun fun fun
md

[mountaindew]

And for fun I will post my first pic of my first part milled using the mach wizards and couple hours experience


Remember your first part
Attachment 214612

[SCzEngrgGroup]

A 4-wire connection to a 220V machine has no benefit. In the US, houses are wired with 220V "split phase", which is two 110V "legs" that are 180 degrees out of phase. Any 220V appliance will use the two "hot legs" and a ground. The neutral wire is needed ONLY if that appliance ALSO uses 110V. As an example, some kitchen appliances, particularly stoves and ovens, will use a 4-wire connection so they have 220V for the heating elements, and 110V for the lights and perhaps electronics. In much of the rest of the world, houses are provided with 220V single-phase, so the three connections are "hot", neutral, and ground, and there is NO 110V usage.

If, as I would assume, the Tormach is provided wired for a 3-wire cord, those three wires will be a ground, and the two "hot" legs in the US, or the one "hot" leg and a neutral in most of the rest of the world, and there is absolutely nothing to be gained by adding a 4th wire - there will be nothing to (correctly) connect that neutral wire to, and tying it to the system ground actually creates a safety hazard.

Regards,
Ray L.

[mountaindew]

A 4-wire connection to a 220V machine has no benefit. In the US, houses are wired with 220V "split phase", which is two 110V "legs" that are 180 degrees out of phase. Any 220V appliance will use the two "hot legs" and a ground. The neutral wire is needed ONLY if that appliance ALSO uses 110V. As an example, some kitchen appliances, particularly stoves and ovens, will use a 4-wire connection so they have 220V for the heating elements, and 110V for the lights and perhaps electronics. In much of the rest of the world, houses are provided with 220V single-phase, so the three connections are "hot", neutral, and ground, and there is NO 110V usage.

If, as I would assume, the Tormach is provided wired for a 3-wire cord, those three wires will be a ground, and the two "hot" legs in the US, or the one "hot" leg and a neutral in most of the rest of the world, and there is absolutely nothing to be gained by adding a 4th wire - there will be nothing to (correctly) connect that neutral wire to, and tying it to the system ground actually creates a safety hazard.

Regards,
Ray L.

I agree 100% as I understand it.
I don't know enough about it to tell if it is good, bad, better, worse.
More research and review of their tech white paper might help. otherwise the machine works just fine as is.

As you stated only appliances that use both 220v and 110v require this and this tool has both 220v and 110v correct?
md

[tbaker2500]

Ray is right. And on the PCNC1100, any 110v wiring is for auxiliary ports, and uses a separate 110v cord.

[mountaindew]

Ray is right. And on the PCNC1100, any 110v wiring is for auxiliary ports, and uses a separate 110v cord.

That's true it is a separate connection.

This is a quote from tormach sb0010 Service bulletin under Electrical connections pcnc1100

"The primary electrical connection for the machine has brown, blue and green wires(black, black, green wires on older machines) The black wires (brown and blue on some machines) are connected to 230 vac hot wires, normally black in household wiring. The green is ground and should be connected to a green household wiring. Some 230 vac outlets are 4 wires with black, black, white, green. White is the neutral conductor and SHOULD NOT BE USED TO GROUND THE MACHINE, even though it may test out with a voltmeter to be the same as ground. Always Check your machine frame to true earth ground with a continuity tester to make certain that you have and effective ground connection. Read section 2 of your manual for additional information. Please see the operators manual regarding the use of GFI circuits."

Im not a master electrician so I have no complete understanding of this. I do like to follow directions.
And they bolded those letters no me

What is correct is still not clear to me.
Ray what problem did you think I could have with a 4th wire ground?


Any help would be appreciated.
Lane,

[SCzEngrgGroup]

What is correct is still not clear to me.
Ray what problem did you think I could have with a 4th wire ground?

What is correct is to wire the machine EXACTLY as Tormach recommends, rather than trying to "improve" it to solve some perceived short-coming.

The problem you could have is creating an unsafe condition by wiring the neutral to the machine frame, exactly as Tormach instructs you NOT to do. If your intent is to simply eliminate the (apparently) separate 110V cord by combining the 110V and 220V supplies into a single 4-wire cable, that can be done safely, but will probably be a step backwards in terms of system reliability, as you'll be making the 110V part of the system more susceptible to noise generated in the 220V part of the system.

Bottom line: You'll get the best result if you wire it exactly like Tormach recommends, and don't try "improve" it. I'm sure the Tormach engineers had good reason for wiring it as they did, and they certainly have a much better understanding of the electrical environment inside the machine than you do. So, don't second-guess them when you obviously don't have a good understanding of how good, reliable, safe AC systems should be configured.

Regards,
Ray L.

[mountaindew]

Im not being clear I guess.
My home has 2 black, 1 white and 1 green wired to oven, cooktop, air conditioner and dryer.

I want to follow EXACTLY what tormach recommends.
And I guess in my case its to not worry about the 4th lug in the plug or the wire box.

Thanks for the help!
lane

[shred]

The reason not to tie the neutral to ground is that only gets to happen one place in your house; at the breaker box. The idea is that if the neutral wire breaks the appliance quits working rather than sending all your neutral return current through the ground which is a safety connection only.

You could run the neutral out to the Tormach, but it would just be sitting there capped off doing nothing since Tormach doesn't use it. Easier to just leave it in the wall.

[kstrauss]

Consider what might happen in an appliance that requires both 220 volt and 110 volts for operation if you were to connect the frame to the neutral and somehow the neutral lead became disconnected. If you turn on the appliance the frame becomes electrically hot; there will be 110 volts between the appliance and a proper ground (water pipe or whatever). The single point of failure can be lethal! With a separate safety ground, if the neutral breaks, the appliance just stops working rather than killing the user.

As others have mentioned, the Tormach does not get 110 and 220 volt power from the same connection so the above comments are not relevant.

[nitewatchman]

You must think of the Ground as a drain that will carry away any leak to the machine frame. The only reason for the neutral is to provide 110VAC by tapping one of the 220VAC legs on the Split Phase circuit. Outside on the pole there is a transformer that takes the high incoming voltage and steps it down to 220VAC using its secondary winding. The neutral is a third conductor that is connected to the center of the secondary winding and divides the voltage into two separate 110VAC circuits (half the windings = half the voltage). This then comes into your home through your main panel. At this point there should be a bonded ground. This assures that the potential voltage in the neutral (the return) and the ground (the safety drain) is the same. Otherwise there could be current flow between the Neutral and Ground at the device in the event of a problem. This is the ONLY place where the Neutral and Ground should be connected.

A common error made by well intentioned electros is to also bond the neutral buss to the ground buss in Sub-Fed Panels. This places the ground wire and neutral wire in parallel making the ground a current carrying conductor, defeats the purpose of the drain and in the event of a defective or high resistance neutral could energize the ground or frame of the device with "shocking" consequence.

So with the winding road explanation, the Tormach does not need or want the neutral since there is no 110VAC derived from it although nothing would prevent that from being done since it happens a few feet up the wire anyway. So for the 220VAC Clip the neutral in the plug (suggest leaving the receptacle intact since it could do other things or provide a dedicated receptacle) and DONOT even consider attaching or bonding the neutral to the machine.

There is also a problem with multiple grounding rods or points setting "ground loops" but that is another long and winding road.

nitewatchman

[mountaindew]

Electrical issue looks to be solved, just want to cover all the bases.
And now I have a much better understand of what is going on and where I was confused.
The help you get on here is great.
Thanks again.



And for fun I Will show my first finished project to go with first cnc mill picture, first fun part picture,
Simple tool holder !
Attachment 214976

Thanks again for the help.
I know I will have years of newbe questions.
Lane

[tbaker2500]

Nice Job!

[mountaindew]

Nice Job!

Thanks!

[cobrakai]

Awesome!

I remember my first cut - I did the whole PCNC test piece outlined in the manual. Then I broke a few tools, sprayed coolant all over the ground, and forgot to turn on the air causing the ATC to get misaligned. Oh what a learning curve this is. I wish I had as much space as you.

If you haven't already, look into GWizard. It's really made the process smoother for me.

[L1z4rd]

Lo

Sent from my GT-I9300 using Tapatalk

[mountaindew]

Awesome!

I remember my first cut - I did the whole PCNC test piece outlined in the manual. Then I broke a few tools, sprayed coolant all over the ground, and forgot to turn on the air causing the ATC to get misaligned. Oh what a learning curve this is. I wish I had as much space as you.

If you haven't already, look into GWizard. It's really made the process smoother for me.

Hi cobra,
Thanks for comment
I downloaded gwiz for a trial a week or so ago.
So much to learn all at one time its hard to decide what book to pick up or what program to use.
I hope to have a chance to use it before trial is up. I should have waited on download I think.

I hit the stop button on the machine now and then! Without that who knows what damage the mill would have done.

I did locate the machine by the door for full walk around access to work on it and maintain it.
That has been a very good decision so far. Makes upgrades and changes far less of a challenge.
I have major range of motion issues from arthritis, so if I want to do something I need lots of room.
I had the power drawbar upgrade a week before the mill arrived.
And I installed it before the machine even had power, for the very same reason.
My hands and fingers cant take or do much these days.
Also the reason for the cnc mill, use a keyboard to fab now.

Thanks for comments
I will post some new pictures of my workspace and how quick it filled up with stuff.
Enjoy the day
lane

[cobrakai]

The PDB is so awesome. Mine came with it, but I couldn't imagine having to manually tighten the drawbar every time. You will be glad you got it.

I have read so much but found that it takes tons of practice and breaking some stuff to figure things out.