Replies

1. 
   WayneL5 | Nov 21, 2004 05:56am | #1

   What does the nameplate on the motor say it runs on?

2. 
   TKanzler | Nov 21, 2004 06:24am | #2

   As WAYNEL5 said, check the motor nameplate.  It's the ultimate authority.  It kind of sounds like the previous owner had it plugged into a dryer receptacle, since a 3-phase plug would most likely be labelled x/y/z/g.  4-blade dryer plugs have a neutral and two hots, plug ground (n/x/y/g or w/x/y/g). 

   There's a good chance it's a single-phase machine.  Or it is three-phase and someone used the wrong plug and receptacle.  You can look on this chart to see what plug is on the saw now, though in the end it's the motor nameplate that tells all.

   http://www.leviton.com/sections/techsupp/nema.htm

   Be seeing you...

1. 
   KesslerCraftsman | Nov 21, 2004 06:11pm | #3

   Thanks to all....  I'll take off the motor cover and see what the machine says.  lp

1. 
   KesslerCraftsman | Nov 22, 2004 07:37pm | #4

   Hi All,

   Don't you just hate when you get bad advice on Knots?  And "bad" doesn't mean incorrect or inaccurate advice...it means hearing advice that you didn't want to hear.

   I pulled the motor cover off and see a little "ph" designation with "3" next to it.  I think that means I've purchased a 3-phase machine.

   Now the issue involves confirming that and then deciding between replacing the motor OR purchasing a rotary phase converter.

   I'll post this as a separate thread, but anyone have experience in deciding between the two?

   In terms of price, I'm looking at Phase converters in the $300-$400 range.  Seems like 3 HP motors run between $500 - $600..for Baldor or Leeson motors.  Cost-wise, all other things being equal, the Phase converter seems like the "right" decision.

   However, if I replaced the motor, I could also be assured of having a new motor, no compatibility issues (if there are any) AND I could upgrade to a 5 HP in lieu of the 3HP.

   Are there issues with phase converters that I should consider?  Noise?  Long-term damage to the motor?  Electricity costs?  Any loss of power?  I see phase converters that are advertised as "not kits....ready to go, in one piece"...how important is this?  I'd like to make this a quick thing vs. mucking around for 2 months..if that makes sense.

   If I bought another motor, could I use the same magnetic switch?

   Any advice based on real experience would be much appreciated... 

   Larry Pile

1. 
   TomMGTC | Nov 22, 2004 09:48pm | #5

   I use a 5hp rotary phase converter that I bought here http://www.rotomaster.com/ over three years ago. Works great and really opens up the options for used machinery.Tom

   Douglasville, GA

2. 
   kevarc | Nov 22, 2004 11:16pm | #6

   Have you thought about contacting the Powermatic first? Verify from them that it is 3 phase befoe spending time and money on something you may not need? I do not understand why people post on forums befoer they contact the maker. It would make sense to do so. You probably would have the RIGHT answer faster.Kevin ArceneauxVisit the Lone Wolf Activities for MS Trainsimulator at http://www.3dtrains.com

3. 
   TKanzler | Nov 23, 2004 12:40am | #9

   "I pulled the motor cover off and see a little "ph" designation with "3" next to it.  I think that means I've purchased a 3-phase machine."

   There are only two choices for the "ph" box, 1 or 3.  Just make sure you're not reading the "hp" box upside down.

   Another way to tell (if belt and suspenders makes you more comfortable) is by the voltage(s) on the motor nameplate.  The typical small three-phase motor nameplate will show either 230/460V, or sometimes 208-230/460V.  Single-phase motors are usually 115/230V, or just 230V for larger ones (like 2 hp and up).  You can also look at the wiring diagram on the nameplate or on/inside the j-box cover.  It will show 3 conductors connected to the motor leads, plus a ground.  Of course, inside the j-box there will also be 6 leads connected to each other and/or the 3 line conductors, plus ground.

   As far as PM knowing what motor that saw had when it was delivered (from it's serial number, I presume), even if they could look it up, motors can be changed, and the older the machine, the more likely it has been.  The only reliable way to know is to look at the motor nameplate.

   For a replacement, Plaza Machinery has a 3 hp Baldor for about $320, and there are other sources besides PM.  I don't know if any C-face motor of the same frame size fits, or if there is anything special about the frame or shaft.Be seeing you...

4. 
   Drose | Nov 23, 2004 03:28am | #11

   I have been down this road.  I looked for and found a lot of info and arrived at this decision.  I spent 320 on the new baldor motor.  Yor current magnetic switch will work.  Go to powermatic dot com and download the owners manual.  It has a new wiring schematic that will probably confuse you for a bit, but it's not horribly difficult.  I think I got my wiring schematic from the guys I bought the motor from.  No problems there.  The motor is stock for that saw and installls easily.

   Dustin

5. 
   migraine | Nov 23, 2004 04:44am | #12

   One of the things to keep in mind is  that a 3hp/3ph motor is smaller than a 3hp/1ph.  Another is that you may /probably wind up have to replace the magnetic stater and some other electrical components also.  This will increase the end cost.  From talking to Phase-A-Matic, you loss about 10% power on a rotory converter, and 30% on a static converter. 

   One thing to keep in mind is that on most 3ph machines, the magnetic switch is run on single phase and the converted leg (the 3rd leg of 3 phase) CAN NOT be used to run the magnetic switch

   I run most of my machines on a 3ph converter(some for 10+ years now) and I rarely have had any problems.  And what problems I did have, were solved by a phone call to Phase-A-Matic.  I have never had to replace a motor that was burned up on a rotory converter.  The only motor that was ever burned up was on a power feeder of mine that I loaned to a friend and he ran it on a static converter.  Some machines should never be run on a static converter.  I found out the hard way and $500 later.  That was to rewind the motor, not replace it

   I don't know of any quick connect sytems out there, but you I would recommend you have a seperate circuit panel for your three phase and you should also use a fused disconnect between your regular single phase panel and your new 3 phase panel/rotory converter.  If you have a little experience with wiring, a rotory setup could take from a few hours to a day to setup, depending on the materials available/knowledge.

   Before you invest in a 3 or 5 hp converter, make sure you know what would your max need be later on.  On a rotory system, you can run 3 times the hp of the stated rotory motor, but, no motor can exceed the max of the rotory motor itself. Roughly speaking, you can run 3 machines that are 3 hp(or 4/5 machines @3hp/2hp/2hp/1hp/1hp) each all at the same time on a 3hp rotory converter.  If my largest moror was 3 hp, I would purchase a 4 or 5 hp rotory converter.  Static converters should be sized individually for each machine.  Meaning 3 machines with different hp, you would need 3 different static converters

   This is what I have been taught over the years.  If any of this is incorrect, someone please tell me

2. 
   HammerHarry | Nov 22, 2004 11:48pm | #7

   In that case, "N" is probably "Z" viewed 90degrees off....

    

    

1. 
   TKanzler | Nov 23, 2004 01:13am | #10

   "In that case, "N" is probably "Z" viewed 90degrees off...."

   <slaps forehead> Doh!

   Be seeing you...

   Edited 11/22/2004 5:14 pm ET by Tom Kanzler

3. 
   Vikingvood | Nov 23, 2004 12:04am | #8

   You can allways build your own phase converter, Thats what I use for all 3 phase Equipment,  Taunton sells a book called Fine Woodwoking on wood working machines & it has the plans in it for building your own from a used 3 phase motor                      http://www.taunton.com/store/pages/070037.asp  I built my own using a 10hp motor & a large relay & some motor start capacitors to start it & it has worked great for the last 10 years.