Replies

1. 
   WayneL5 | Jan 24, 2004 08:37am | #1

   The lamp will pop like a flashbulb.

   230 and 250 volt lamps are available.  250 volt lamps will last much longer with lower light output than 230 volt lamps, but either will work just fine.  You can even get left handed threads if you want.

   Have you checked inside the pothead (that is, the wiring compartment of the motor)?  Usually the motor manufacturer puts a label inside if the wiring diagram is not stamped on the outside.

1. 
   wrudiger | Jan 24, 2004 09:12am | #2

   Thanks for the info on the bulb - had a feeling that was the case. Glad to hear there is a 230V alternative.

   There are no wiring diagrams inside the housing.  These guys are giving Taiwan a bad name! I just rewired the Delta (Taiwan) DC and a) there was a wiring diagram inside the housing, b) it matched the manual and c) only had 4 wires...

2. 
   JohnWW | Jan 26, 2004 06:39pm | #3

   You can leave the light wired for 110 volts by connecting the light circuit between one of the hot leads and the neutral on the incoming power to the drill press.  To do this you will need to use a four wire cord into the drill press, two hot leads, a neutral, and a ground.  The neutral won't be needed for wiring the motor.

   John W.

    

3. 
   TKanzler | Jan 27, 2004 02:58am | #4

   It should presently be connected {Line A + 1 + 3 + 8}, {Line B + 2 + 4 + 5}, though 5 and 8 may be swapped (for opposite rotation)

   For 240V operation, it should be {Line A + 1}}, {Line B + 4 + 5}, and {2 + 3 + 8}, though once again, 5 and 8 may be swapped.

   5 and 8 are the start winding leads.  If you have a multimeter, you can check continuity and DC resistance across 1 and 2, and also across 3 and 4.  They should measure the same, as they are the leads for the two windings.  Across 5 and 8, you should measure a fairly high resistance, which will slowly increase as the capacitor takes a charge from the ohmmeter.

   In the 120V configuration, you're putting the three windings in parallel with Line A and Line B at each end.  For 240V, the two main windings 1-2 and 3-4, are in series, but with the start winding in parallel with 3-4.

   Hope that helps.

   Be seeing you...

1. 
   wrudiger | Jan 30, 2004 09:46am | #5

   Tom,

   Thanks for the detailed reply.  Feel like a dummy - although the instructions only cover 4-wire motors, inside the back cover is the 6-wire diagram. Duh!

   For the light I ran the neutral on the light circuit to ground (since the ground within the tool is actually connected to the common at the plug) and it all works great.

   Wayne

1. 
   TKanzler | Jan 30, 2004 06:11pm | #6

   The connection diagram in your manual is for a non-reversible motor; that's why it has only 4 leads.  The start winding is permanently connected in parallel with one of the run windings.  By reversing the leads of the start winding, you're reversing the magnetic polarity of the start winding relative to the magnetic polarity of the run windings, which reverses the direction the rotor is pushed/pulled during the start.  If you had no start winding, you'd have to give the motor a little push in one direction or the other; it will run equally well in either.

   But the wiring you've done for the light is a no-no.  The grounding system is not supposed to carry current, other than to clear a ground-fault.  If you lose the ground (like a poor connection between the ground pin on the plug and the receptacle, or a damaged cord, or a conductor pulled out of the plug, or any of a load of other possible reasons), you'll have 120V on the frame of the tool, with no GFCI protection, while you're standing on a concrete floor (same as dirt, for all practical purposes).  To do it right, you need a 4-conductor cord (B/R/W/G) with 3-pole grounding plug and receptacle.  You'll also need to wire the (3-pole  plus ground) receptacle with 3 current carrying conductors and a ground, like 12/3/G non-metalic cable (NM-B, or Romex), or the equivalent in conduit. Then you'll have a neutral all the way back to the service equipment (main panel, most likely) to carry the bulb, and the ground can do what it's supposed to: nothing, until it's needed to trip the breaker and clear a fault.

   Look at the 14-15P/R and 14-20P/R plugs and receptacles on the following links.  There are also locking versions.  http://www.networkcable.com/pages/components/nema_nonlocking.html

   Be seeing you...

   Edited 1/30/2004 10:15:37 AM ET by Tom Kanzler

   Edited 1/30/2004 10:22:08 AM ET by Tom Kanzler

1. 
   wrudiger | Jan 31, 2004 07:20pm | #7

   Thank you for that clarification!  I do have 12/3+G to the box; I will replace the recepticle/plug and rewire the line to the motor and light to make it safe.

   Now that I think about it I'm confused.  Since there is only a 3-wire cord as supplied by Jet and shown in manual, when reqired for 220V  black and white become the two current-carrying wires and the green becomes the common.  And thus there is per the Mfg spec no true ground within the machine.  Am I missing something here?

   I really appreciate your efforts to keep me from doing something stupid!

1. 
   JohnWW | Jan 31, 2004 09:03pm | #8

   Single phase 230 volt doesn't need a common or neutral line to create a circuit.  The two hot leads are 180 degrees out of phase with each other.  The current flows between the two hot leads only, in one lead and out the other, the current flow reversing at 60 cycles per second.  Unless there is a problem, the ground doesn't carry any current. 

   I think that Jet was remiss in not explaining in their manual that the machine would need to be rewired with a four conductor  power cord to run the motor on 230 volt while keeping a 120 volt circuit for the light. 

   John W.

2. 
   TKanzler | Feb 02, 2004 08:02pm | #9

   I agree with JohnW that Jet was remiss in not clearly requiring a flexible cord upgrade to 4-conductor cord.  Flexible cord, by the way, has all conductors insulated, so for 3 current carrying and one ground, you need 14/4 (or whatever gauge).  For flexible cords with 3 current carrying conductors, the ampacity is the same as it is for building wire.  Your saw probably has a 14 gauge cord (15 A with 3 ccd's and 18A with 2 ccd's), which would be more than enough when rewired for 240V (you'll have only half the original motor current, plus one little bulb on one leg). 

   But if 14 gauge SJ cord is too thick for the strain relief at the tool, consider 16 gauge (10A rated with 3 current carrying conductors, 13A with 2).  Voltage drop and subsequent motor performance degradation with a light gauge cord is rarely a problem when wired for 240V, unless the run is extremely long; that's probably the biggest single reason for switching to the higher voltage.

   As far as cord outside diameter goes, SO cord has 600V insulation, and is almost twice as thick as SJ, which has 300V insulation.  Those are the two types sold in the big boxes.  And if you're going to change the cord on the saw, now's the perfect time to add some length, if you've found the stock cord to be a bit short for your needs.

   One last comment.  Green, green with one or more yellow stripes, and bare are always grounds, and only carry current in the event of a ground-fault, and even then, only long enough to trip the breaker and clear the fault (thereby eliminating the hazard), although it will be a very large amount of current for a very short time (possibly thousands of amps).Be seeing you...