Drum switch moved

It seems my Drum switch might be going out. It takes a couple of tries to sometimes get it to turn on.
I see some on Ebay for over $100. That seems to be a bit pricey for me.
I believe $50 or less to be a fair deal.
Where is there a replacement switch like it to be found?
 
Excluding eBay, the cheapest one that I've found that might work is $65 from Grainger. It is Dayton brand, so obviously Chinese. Approximately the same thing in a Square-D brand is about $175. So if you see a US branded one on eBay for only $100, it qualifies as cheap. Nothing costs what it used to.
 
I'll take it apart this weekend and see if it's repairable first.
For that kind of "green", I can buy quit a few of the cheap ones.
Just needs to be 15A for a 1/2 HP motor 115VAC.
 
Yes, I would likely buy the Dayton myself. If you do go to buy one of them, be sure that you take the switching diagram of the one that you have and get one that matches. Although I've no idea whether any of the Dayton switches fall into this category, I know that there are drum switches made that will reverse a permag DC or a 3-Phase motor but cannot be wired to reverse a single phase AC or shunt wound DC motor.
 
Two other comments on the switch mounting and bumping the switch. First, with a single phase motor, quickly switching it from FWD to REV will probably not hurt anything as long as it is done quickly. The start winding circuit is disconnected by the centrifugal switch and if the drum switch is properly wired (so that you are switching the phase of the start winding, not the run winding), all that happens is that you momentarily interrupt the current to the run winding. Second, if you mount the switch right up under the pan and with the lever pointing toward the tailstock, I think that you will reduce the chance of bumping it with your knee. And if you do bump it while it is running, the bump will be trying to put it into the position that it is already in anyway.
 
Call Matt at Lost Creek Machine. He has a variety of switches on the shelve that are not on the website. He might have what you need for a reasonable price.
 
I was using the lathe and it stopped right in the middle of parting off a piece of 4140. Smoke came out of the switch and I flipped the master switch off ASAP.
Took the drum switch apart and now I see what the problem was. :(
I'll check with a couple of Electrical supply shops tomorrow in town and see what they have and prices.
Until I get one I won't be doing anything on the lathe.

upload_2015-4-29_23-21-26.png

upload_2015-4-29_23-21-44.png

upload_2015-4-29_23-22-11.png
 
upload_2015-5-7_22-38-52.png upload_2015-5-7_22-39-2.png upload_2015-5-7_22-38-25.png upload_2015-5-7_22-37-55.png upload_2015-5-7_22-38-37.png I got a new Drum Switch. But I am having problems wiring it.
If anyone can look at these pics and tell me what wires go where, I would appreciate it.

I have 4 wires to the motor. Yellow - Red - Brown - Black
When I check continuity, the Yellow and Brown are the only ones with continuity.
It seems that some of the connectors on the switch are connected to one another by the metal strips on the sides.
That is what is confusing. No matter how I try to wire it, it keeps tripping the breaker.

upload_2015-5-7_22-38-52.png upload_2015-5-7_22-39-2.png upload_2015-5-7_22-38-25.png upload_2015-5-7_22-37-55.png upload_2015-5-7_22-38-37.png
 
Mike,

First, there is no standard color code for wires in motors. You need to post a photo of the motor showing its hookup diagram. However, assuming (you haven't said what type motor you have other than implying that it was a 1/2 HP) that the motor is for 110 to 120 VAC, single phase, probably the yellow and brown leads go to the run winding and the red and black go to the start winding. The start winding, if this is a capacitor start single phase motor (today the most common type, but not the only type), the run winding will show continuity with an ohmmeter but the start winding will not because there is a capacitor in series with it.

Second, based only on the drawing photo headed "Wiring diagram and switch actions:", this isn't a safe switch to use for a single phase motor as one side of the AC line will always be connected to the motor. Not too bad if that side is the Neutral. But in house wiring and with plug in power cords, you can never be sure which is Neutral and which is Hot. As shown on the "Wiring diagram", this switch was made to run and reverse a 3-phase 3-wire motor (Neutral not used).

However, there appear to be unused connections, at least as shown in the one wiring diagram. So do this. There appear to be a total of 10 places where you can connect a wire. Partially disregard the numbers shown in the casting. Call the five terminals on the left side of the switch 2, 4, 6, 8, 10 from top to bottom as shown in the photos of the switch. Call the 5 terminals on the right 1, 3, 5, 7, 9. Note that this moves 5 up in the diagram in the casting and changes what was 5 to 7. Plus it adds 8, 9 and 10. Take the ohmmeter and check which other terminals 2, 4, 6, 8 and 10 connect to with the switch in FWD and with it in REV. From the photos and the Wiring diagram, part of the chart you need to draw will I think look like this:

With switch in FWD
2 to 1
4 to 10, 3 and 5
6 to 8, 7 and 9
8 to 6, 7 and 9
10 to 4, 3 and 5

With switch in REV
2 to 1
4 to 10, 7 and 9
6 to 8, 3 and 5
8 to 6, 3 and 5
10 to 4, 7 and 9

If all numbers are correct, I think you could make it run your motor temporarily by connecting the Neutral in the line cord to 4 and the brown motor wire to 10. Connect the Hot wire in the line cord to 2 and 6. Connect the yellow motor wire to 1, the red to 3 and the black to 7 (5 in the casting photo). If it runs backwards, swap the red and black. But the Neutral is not switched.
 
You must log in or register to reply here.
Back
Top