Powermatic on/off switch

Re: Powermatic on/off switch

Dave Paine

I think a picture of the multimeter and the switch will help others to assist.

What are you wanting to check? That the switch breaks the contacts?

Without a picture, I do not know if the contacts go from side to side or top to bottom.

If wanting to confirm the switch is making/breaking the connection, you would use the Resistance setting and have one of the probes on e.g., input and the other probe on the output. When the switch makes contact the multimeter should beep and read 0 ohm. When the contact is broken the multimeter should show open circuit or infinite ohms.

Re: Powermatic on/off switch

Dennis in Southern Oregon

Ken, first UNPLUG the lathe. Second, check your multimeter as follows: Set the control to measure resistance. That position should be marked as "ohms" or a Greek omega ( looks l like a fat upside-down "U" with feet). With the probes held together, the meter should read zero and when they are separated, the meter should read a very high number.

I have not seen a powermatic switch, but if you are using 240V power, both hot leads will be controlled by the switch. Most likely there will be a pair of terminals on one end of the switch that connect to incoming power (call them A and B) and a pair of terminals on the other end that connect to the load (call them a and b). (a should be directly across from A; likewise b and B)

Now, with the power switch in the off position, place one probe on A and the other on a. You should read a very high resistance. Ditto with probes on B and b. Now turn the power switch to the ON position and repeat these operations. The resistance should read very close to zero. You might want to snap the switch a few times and repeat this test in case you have an intermittent switch.

Re: PM Switch links

Doc Green

See the article below for pictures and details on how to check the switch.

http://www.docgreenwoodturner.com/pmcontrol2.html

This article shows how to replace the switch. Note that you do not have to replace the entire assembly.

You don't have to disassemble the unit to the extent shown in the article.

http://www.docgreenwoodturner.com/pm3520switch.html

Good Luck, ~Doc

Re: Powermatic on/off switch

Doc Green

Dennis, the Start/Stop switch on the Powermatic switches only a low-voltage control signal, not the 220 V main power. The voltage involved is only about 16 VDC.

~Doc

Re: Powermatic on/off switch

Dennis in Southern Oregon

Interesting. Does this mean that there is no switch at the AC input?

Re: Powermatic on/off switch

Doc Green

You are correct: there is no switch for the line current. When you plug the thing in, the display will light up and power is applied to the inverter.

I have heard many local discussions as to whether it is best to leave it on all the time, or plug and unplug it every time you use it. No general agreement is to be found in that regard, however.

I know several people (I'm one of them.) who have installed a switch in the line so that power could be removed without having to deal with the plug. It's not a big deal to do. Get a double-pole, single-throw switch and run a hot wire through each side of the switch.

Such a switch can be purchased at any big box store. It fits behind an ordinary switch plate like an ordinary light switch.