Power Switch

dusty · Post by **dusty** » Sat Jul 07, 2007 7:35 pm

I am unable to cross that identification data to any other part number. In fact, the McGill data sheets don't even list that number.

I suspect that it is a number created by McGill for Shopsmith and cannot be purchased by anyone except Shopsmith. The numbers for the SS motors are that way, also.

The switch is DPST (double pole, single throw). It is double pole because it has two sets of contacts that are switched. It is single throw because there is only one position that is "on".

In other words, it switches both the hot side and the neutral side of the SS motor.

The white wires (Neutral) connect to one pole and the black (Hi Line) and blue (Hi Load) wires connect to the other pole.

http://www.kpsec.freeuk.com/components/switch.htm

My curiousity has cost me, however. I removed the switch, which was working fine, so that I could read the part numbers on mine. There were none. My switch was manufactured by Leviton.

It now needs to be replaced. The plastic tabs that secure the switch were brittle and when I pressed on them (to remove the switch) three of them broke off. I'm not out of service but I have to order a new switch. The old one is now held in place by silastic.

billmayo · Post by **billmayo** » Sun Jul 08, 2007 11:45 am

Shopsmith has switched to using only a single pole on the power switches used on the Mark V. See the following instruction:
MARK V Motor Replacement (19KB) at http://www.shopsmith.com/ownersite/productmanuals.htm
I have been using 20 Amp SPST switches as replacements for some time now. When using the DPST switches, if one side shorts or opens, you can temporary switch the black/blue wire to the other set of contacts until a replacement is available. I only use insulated quick connect terminals on all the wires. A white to white wire jumper (connector) was included with the switches I ordered from Shopsmith.

Bill Mayo

dusty wrote:I am unable to cross that identification data to any other part number. In fact, the McGill data sheets don't even list that number.

I suspect that it is a number created by McGill for Shopsmith and cannot be purchased by anyone except Shopsmith. The numbers for the SS motors are that way, also.

The switch is DPST (double pole, single throw). It is double pole because it has two sets of contacts that are switched. It is single throw because there is only one position that is "on".

In other words, it switches both the hot side and the neutral side of the SS motor.

The white wires (Neutral) connect to one pole and the black (Hi Line) and blue (Hi Load) wires connect to the other pole.

http://www.kpsec.freeuk.com/components/switch.htm

My curiousity has cost me, however. I removed the switch, which was working fine, so that I could read the part numbers on mine. There were none. My switch was manufactured by Leviton.

It now needs to be replaced. The plastic tabs that secure the switch were brittle and when I pressed on them (to remove the switch) three of them broke off. I'm not out of service but I have to order a new switch. The old one is now held in place by silastic.

jtomwoods · Post by **jtomwoods** » Sun Jul 08, 2007 2:00 pm

Gentlemen,

I did contact SS yesterday, and they are sending me a replacement switch at no cost (of course, they are now on backorder).

I am sorry Dusty experienced damage to his switch. On the other hand, I appreciate his desire to gather data for problem solving. I am grateful for all the help.

I may look into other switches as well. At $25.00 a pop, I've spent the equivalent of some new tools just to have functioning power switches

dusty · Post by **dusty** » Sun Jul 08, 2007 2:47 pm

Think nothing of it, Tom. I am quite use to getting myself into trouble. It costs me something nearly everytime. My wife says I do it on purpose.

I am disappointed that I was unable to identify an alternate source. Though we have learned enough to be able to replace the switch with something that works but it just wouldn't look right without something very nearly an exact match to original.

A 20 amp switch of nearly any sort would work if you're inclined that way; I am not.

I'll add to the backorder list as soon as I am sure there is nothing else "I need". I just may wait awhile for a big sale.

robg · Post by **robg** » Mon Jul 09, 2007 8:16 pm

I would be interested in hearing about what is causing the problem if you ever find out. It certainly sounds odd.

dusty · Post by **dusty** » Mon Jul 09, 2007 9:06 pm

It is very doubtful that we will ever know. Without a component failure analysis on a representative sampling of the failed items, all theories are pure conjecture.

I suspect that there was a run of switches that either were built with contaminated materials, or the contacts did not make proper connection. Either condition could result in a build up of heat due to excessive arcing at opening or closure of the contacts. Over time you get premature failure.

charlese · Post by **charlese** » Mon Jul 09, 2007 9:42 pm

jtomwoods wrote:I just had my third failure of a headstock power switch in the last 8-9 months. Has anyone had similar problems? They are essentially sealed, so I am at a loss as to what I can do to prevent them from failing.

Also, I noticed Grizzly Tools has a switch that looks identical to the one on my SS for only $3.95. Has anyone tried it?

No one has mentioned this yet (I think). J. Tom, have you checked your shop power source? Is it 117 to 120 volts? Are you using an extension cord?

jtomwoods · Post by **jtomwoods** » Tue Jul 10, 2007 8:09 am

I thought about the power source too. I had it installed about two years ago to be dedicated to the SS. I do use it with other tools (planer, for example) but not at the same time as the SS.

When I talked with customer service over the weekend, they indicated that there were some issues with the switches whereby dust can get in them. The switches seem to me to be sealed for the most part, but I guess dust has a way to find itself into nooks and crannies.

dusty · Post by **dusty** » Tue Jul 10, 2007 9:05 am

Let's just think about this for a minute.

Some of us have had a SS for many, many years and have never had a power switch failure.

Still others (at least one) have experienced three of more switch failures in less than a year or two.

Unless you have an awfully 'dusty' shop, I seriously doubt that dust is the root cause of your failures.

If SS does, I certainly hope they have a plan for eliminating that point of vulnerability. Most all SS operate in a 'dusty' environment.

jtomwoods · Post by **jtomwoods** » Tue Jul 10, 2007 9:40 am

I agree that our shops can get "dusty". I do housekeeping every day. In fact, my wife feels I should do more housekeeping in other areas of our home.

I am perplexed to say the least.

SS said they did revise the switch, and I may have used the "old" ones. Yet, my father in law has a 30 year old SS and has never replaced a switch. So, the saga continues.