# drum switch and single phase motor



## icore3user (Feb 23, 2013)

My Index model 55 x feed motor is shot. I was thinking of picking up a Harbor Freight 1/2 hp reverseable motor and wiring it to the drum switch that controlled the now dead 1/4 hp 3 phase 220v motor. 
Based on the wiring diagram for the motor from Harbor Freight, the connections should be like this.
 The neutral position is not shown since there is no continuity on the contacts. Does it look right?
 It looks right to me. I'll just grab the 2 incoming hots and by pass the 3rd coming from the static converter, to refeed the lower drum switch,
	

		
			
		

		
	



	

		
			
		

		
	
 the main motor ( 3 phase 220v ) and it's 2 speed forward / reverse drum switch will remain untouched. This should fix my x feed drive issue.


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## Halligan142 (Feb 24, 2013)

That's not going to work.  You have L2 hooked into T 3,4,and 5 which are supposed to be isolated together, not with a power leg.  Also T4 is hooked into two terminals at the same time by the pictures you posted Here's what you want  
	

		
			
		

		
	



	

		
			
		

		
	
  You will only be breaking one hot leg to the motor so you will constantly have 115V to the motor but it will not turn.  Just be aware of that.


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## wa5cab (Feb 24, 2013)

I don't think so. Or if I correctly figured out what the three drawings are of, no. You don't ID the three drawings, but if the upper drawing shows how HF says the motor must be wired for CW and CCW and the L's, P and T's are motor terminals, and the lower two drawings (without the L's, P and T's) show how the switch switches (a standard U/E configuration switch), that won't work. 

The assumed motor diagram shows three terminals not connected to either side of the line in CCW and three not connected to the line in CW. Two of them (T2 and T3) are NEVER to be connected to Line. 

If my assumptions above are correct, then here is how you need to connect it. Connect L1 and P1 as shown (lower left and lower right switch terminals). Connect L2 and T4 to the upper left terminal. Connect T8 to the center left terminal. Connect T5 to the upper right terminal. And connect T2 and T3 to the center right terminal. This will, of course, always leave 115VAC on the motor. But with this type of switch, there is no way around that.

DISCLAIMER - Conclusions in Paragraph 3 assume that all of my assumptions in Paragraph 1 are correct.

EDIT - And Halligan's solution, written while I was writing mine, will also work.

Robert D.


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## wa5cab (Feb 24, 2013)

I also meant to ask why you don't just replace the motor with another 1/4HP 3-phase machine?  I assume you know that starting surge current in single-phase motors is higher than in 3-phase.  And then you've doubled that again by decided to up the motor size to 1/2HP.  The starting surge is also affected by the load the motor is starting against.  You might better check the current and motor HP rating of your switch.  I don't recognize it so can't say what its rating might be.  

Robert D.


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## icore3user (Feb 25, 2013)

Robert,

The reason I was thinking of going the HF 1/2 single phase solution was due to availability and cost. I found 3 phase 1/4 hp nema 56 motors, but for 413.oo plus tax / shipping. Next size up in 3 phase was 1/2hp, and the price dropped to 236.oo plus tax/ shipping. for some reason 1/4 hp 3 phase motors are harder to find in nema 56, i can find them in 56c, but that mount will not work sort of making a new mount for it.  But tonight after some more searching I found a Leeson 1/4 hp 3 phase nema 56 motor for 137.00 ( part #100027 ) , plus shipping. That seems reasonable. I downloaded the cut sheet and the spec sheet and it will be a pretty good match, and fit. I prefer the 3 phase replacement to single.

The load against the motor is rather low ( probably why there is 1/4 hp motor in the first place ), as the pulley at the motor is only 1 1/4" and driving a 6" pulley at the other end, which turns a low gear into a multi speed gear box. I could turn the 6 inch pulley by hand rather easily. This turns the x feed via a u joint and drive shaft ( very much like a car ). Later models (  Super 55 ) had the drive motors on the knee and not on the inside of the pedestal base unit.

The drum switch is a old Cutler Hammer forward / reverse drum switch, no part number on the switch, no specs on it. Since it was built in 1955 or so, I'll take it is probably good for at least 15 amps min ( judging by the contacts on the switch ), everything I have looked on this mill seems beefy, so I would not doubt the same applies to the upper hi / lo speed forward / reverse drum switch and the lower forward / reverse drum switch

I thank both you and Halligan for the replies. I re drew the drawing ( with both methods of wiring ) and saved it to my computer for future reference.


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## wa5cab (Feb 26, 2013)

OK.  You're welcome.  I understand that it also must fit mechanically.  A good percentage of the ones on eBay tonight are in fact 56C, which would as you say require some sort of adaptor mount.

Robert


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