1 or 2 dedicated 120VAC circuits for my CNC?

RELAYS
Yes, you've got it correct with #8 being DC+ and #7 is DC-
You'll find that there are a few different relay contact numbering schemes used worldwide.  The symbols I used don't really follow a numbering scheme because I'd need 3 or 4 different symbols for each relay type in my wiring diagram library to cover all the numbering schemes.

But if you look closely at the picture on the relay (and I think you did) you can see the pairs of NO/NC contacts along with the COM, plus the coil connections at the bottom.  The coil diagram looks a little odd because they've drawn a flyback diode as well.

CONTACTOR
The Eaton is rated for 15.5A regardless of voltage, so go with that one.

tommylight wrote:

Never used them, but from the above spec i really do not trust Eaton, at all.
Notice how the Fuji rated current drops with the rise in voltage, Eaton does not.
Since you are using a single phase, you can always parallel relay contacts for more current.
 

DOH!

Why not Eaton?  I've haven't used a ton of their stuff, but I've got two VFD's and some other components doing OK.

spumco wrote:

 As you've probably discovered already, everyone has their own opinions about what to do. 
 

Q.E.D.

The coil diagram looks a little odd because they've drawn a flyback diode as well.

Apparently this particular relay includes...

• LED indicator for monitoring operating status and diode surge suppression for limiting voltage spikes

Not sure if that is good or bad in my situation? I assume it should work fine?

It's good in every situation.  LED is optional but nice, diode is required in many cases to protec whatever is triggering it (i.e. Mesa).

Notice how the Fuji rated current drops with the rise in voltage, Eaton does not.

Yes I noticed that and was curious why? So is your take on it that they are not posting accurate numbers? I see this all the time with Chinese stuff but I was under the impression that Eaton was a pretty good company.

Since we are on this subject can you guys give me your opinion on which companies are the better ones to look for in the electronics industry? Here are some of the brands I see all the time, at least in the relay/contactor category. If you have others that you would recommend that would be great. 

• Dayton
• Schneider
• Eaton
• Fuji
• Allen Bradley
• GE
• Siemens
• Sprecher + Schuh
• WEG
• Omron

Since you are using a single phase, you can always parallel relay contacts for more current.

That is interesting. So does this double the current, or is there a calculation to determine what it would be?

Thanks

My opinion - subject to change if Tommy tells me I'm all wrong...

All the companies listed are fine.  Some are significantly more expensive when new than others.  And there are plenty of other 'top-tier' or nearly top-tier component OEMs.  I'm sure there are dozens I've never heard of, much less used or seen.

You want another rabbit-hole homework assignment?  Go to HGR Surplus's site, and search for "enclosure" or "control" or similar.  They've got tons of used industrial electrical & electronics stuff, and if you zoom in on the photos you can start to get an idea of what people use when money is no object.

Look at the CNC machines and other automation equipment and check out the close-ups of the control cabinets.  Ignore the drives & VFD's - look at the relays, contactors, power supplies, and other 'commodity' components.

Same thing for motion hardware.  Hi-win linear rails appear to be the cat's meow in the hobby/printer world compared to no-name ebay stuff... but you won't find them in frequently in industrial equipment.  THK, Bosch-Rexroth, IKO, Thomson Linear, and others never found on a 3D printer.

Keep in mind that the brands you come across are regional.  Lots of Allen-Bradley over here, Siemens, AB, & others in Europe.  Mitsubishi Electric for Japanese equipment.  It varies, and some equipment manufacturers stick with suppliers they know even if they could save money with a perfectly good substitute.

Sray69 wrote:

 

• Since you are using a single phase, you can always parallel relay contacts for more current.
  That is interesting. So does this double the current, or is there a calculation to determine what it would be?
  
  Thanks

That one's beyond me.  I don't know if I've ever seen a rating for individual contacts or how the rating is determined.  Is a "20A" contactor good for 20A per contact, or 20A shared between all three (or 4 or 2)?

Good question.