Splitting Hot Leads to both sides of Toggle Switch

[BuffaloBill]

In my wanderings through the postings I recall someone suggesting you could improve the longevity of the Toggle Switch (Mine is the bat style original) by runniung the Neutral directly to the Motor and split the Hot lead inot two and run them in parallel through the toggle switch.

This seems like a good idea to me but in the thread I read this a discussion of that particular idea didn't develop (The main topic was about something slightly diffrent).

So I'm left wondering if I should do that as part of my current rebuild.

If any of you have a more experienced perspective on this I'd appreciate your input.

Cheers,

Cody

[dusty]

In my wanderings through the postings I recall someone suggesting you could improve the longevity of the Toggle Switch (Mine is the bat style original) by runniung the Neutral directly to the Motor and split the Hot lead inot two and run them in parallel through the toggle switch.

This seems like a good idea to me but in the thread I read this a discussion of that particular idea didn't develop (The main topic was about something slightly diffrent).

So I'm left wondering if I should do that as part of my current rebuild.

If any of you have a more experienced perspective on this I'd appreciate your input.

Cheers,

Cody

I'm not sure that I understand what you mean by splitting the hot leads and running them in parallel through the switch.

If you are using a DBST switch, you have essentially two switches operating at the same time. One switch is switching the hot lead (black wire) while the other switch is switching the neutral lead (white wire).

You can connect the neutral wires (white wires) direct using no switch for the neutral side. In this manner, one side of the switch is an unused spare while the other is doing the work. If you have the right size switch, this poses no more electrical stress on the switch at all.

When the switch does finally fail, utilize the other side of the DBST switch.

You have in effect doubled the life expectancy of the switch.

[BuffaloBill]

This is the one I was referring to:
https://forum.shopsmith.com/viewtopic.php?p=27355&postcount=17
Cody

[dusty]

This is the one I was referring to:
https://forum.shopsmith.com/viewtopic.php?p=27355&postcount=17
Cody

It seems that you accurately repeated what the other poster had said. However, I have not changed my position.

Maybe this Sawdust Session will help us both. Please do not overlook the information that is posted on The Blackboard. Just hover on numbers 1,2 and 3.

That which is depicted at #3 is what I advocate.

[BuffaloBill]

It'd be good to hear from anybody who may have tried it.

In most wear issues I'm familiar with wear rate does not increase linearly with load and wear rate usually increases with accumulated wear.

As an example diustributing the load across two bearings will tend to last longer than loading one bearing completely and then replacing it with the second bearing.

Would this logic not also apply to toggle switches. If half the amps are going through the switch I'd expect more than twice the lifespan.

Cheers,

Cody

[dusty]

It'd be good to hear from anybody who may have tried it.

In most wear issues I'm familiar with wear rate does not increase linearly with load and wear rate usually increases with accumulated wear.

As an example diustributing the load across two bearings will tend to last longer than loading one bearing completely and then replacing it with the second bearing.

Would this logic not also apply to toggle switches. If half the amps are going through the switch I'd expect more than twice the lifespan.

Cheers,

Cody

The theory sounds good. Less current would result in less arcing when the switch contacts open/close. Having two paths (through the switching contacts) would result in half the current (thus less arc).

So maybe.

But not in my machine.

If you do this and report results, I'll be here to read them.

[JPG]

Switching a single load with a two pole switch will not double its life, nor split the current in a meaningful manner.

With the two poles wired in parallel, the pole making first will experience the start up current surge while the pole making second will experience less.

When turning off, the pole opening last will experience the turn off arc and the pole opening first will experience nothing.

Since the poles do not switch simultaneously, the parallel connection becomes a luck of the draw as far as on/off induced wear is concerned.

The description above is applicable except the first/last sequence/wear is reversed when wired to switch both sides of the incoming power source.

Net gain = 0.

Now using only one pole will enable using the second when the first fails, but only if the failed pole does not prevent the second from operating properly.


IMHO not worth the effort except as a temporary 'fix'.

[garys]

It probably isn't worth the effort. The switch on my Shopsmith has been hammered on and off many times a day since the unit was built in 1982. When the switch dies, I figure it has earned a new one.

[billmayo]

15 Amp toggle and rocker switches can fail on the Shopsmith. The 3/4 motor has an initailize current flow of around 20 Amps and the 1 1/8 HP motor draws arounf 24 Amps at startup. The switch will arc then turned off which can result in burnt points over time. I have be using motor grade 20 amp rated toggle and rocker switches for nearly 10 years with no failures every reported with the HD 20 amp switches. Thes swirches uses a larger contact point to handle more current.
http://www.delcity.net/store/Heavy!duty ... 789066.a_1 DPST 7300001 $5.41 is an excellant power toggle swith.

[billmayo]

This is the one I was referring to:
https://forum.shopsmith.com/viewtopic.php?p=27355&postcount=17
Cody

By removing the netural wire from the switch to hook directly to the motor, You can parallel the load across both sides of the switch. I have used this capability for larger motors that draws 30 Amps to operate by splitting the 30 Amo into 2 parallel circuits handling 15 Amp each. This will not meet any electrical code switch requirements when splitting the amp power into 2 identificual branchs to cut the amps in half. ,