Unisaw #36-812 Switch Problem

craftbeerguy

Craft Beer Guy
User
Afternoon,

My Unisaw switch has an issue with turning on and off, often requiring a few pushes for either operation.

I'd first ask if anyone else has experienced this problem with this model? Compressed air blowout didn't solve anything.

I managed to dig up the original "Replacement Parts" document. The main components as I see it are a "Switch" (basically a cover with buttons) and an "Overload" part. Quite a difference in price between the two. There is also a Switch Overload Kit running over $300 which likely includes the first two.

There are several replacement part options. The originals are showing obsolete through 3rd party vendors along with their corresponding new part number. There are no Delta Service Centers that I'm aware of. Is there a way to diagnose this?

Thanks in advance
 

bob vaughan

Bob Vaughan
Senior User
The Unisaw has had lots of 'switch' options and types since it first came out in 1939. Some answers will be correct for some starters and not others. In the later years Delta started putting Taiwan/Chinese-made switches on the Unisaw. Those proved to be the most troublesome particularly on motors over 1-1/2 HP. Below are some photos of an Asian-made switch that came from a newer Unisaw. Observe the size of the burned contacts. They were running a 3 HP single phase motor. The big square contact set at the bottom is from a USA-made NEMA size 1 starter that should have been used on a motor that size.


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bob vaughan

Bob Vaughan
Senior User
Did some further switch research. Turns out that the above photos are correct for your type switch according to Delta's parts illustration. I tried to source a new starter once to repair the one shown. No luck. I had to silver solder on new contact points but I got it working again.
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craftbeerguy

Craft Beer Guy
User
Bob/Gene, Thanks a bunch for the research and help! A real eye opener looking at the burnt contacts. The ...........0199 part # on the pic is what I have on the on the saw. I did notice the stop button was a bit sticky and after freeing it up, it's currently behaving. Mine is a 1ph 3hp.
 

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bob vaughan

Bob Vaughan
Senior User
When that switch does go, probably an Asian-made replacement would be suitable for the short term. That switch (technically a magnetic motor starter) has three sets of contacts in case it needs to be wired to a three phase circuit. This means you've got an extra unused set of contacts in there that can be swapped out for a set that's too burned up to use.


For the long term, a good USA-made switch like the ones that used to come on that saw would be nice.


Below, a USA-made 1980s low voltage control mag starter being retrofitted to a 1950s Unisaw.

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Dee2

Board of Directors, Vice President
Gene
Staff member
Corporate Member
Not what I would have. Best for your continued success with the switch.
 

chris_goris

Chris
Senior User
Bob/Gene, Thanks a bunch for the research and help! A real eye opener looking at the burnt contacts. The ...........0199 part # on the pic is what I have on the on the saw. I did notice the stop button was a bit sticky and after freeing it up, it's currently behaving. Mine is a 1ph 3hp.
Go to Grizzly and look for any 3Hp piece of equipment they sell. Then look at their replacement parts, now heres where it gets tricky. They will carry the "same" part (specifications wise) with different part numbers for different machines. For instance a 3HP tablesaw may use a different switch than a 3HP jointer, but either switch will work. Now the underlying thing to look at is the specs from your current switch Vs what they offer. You should be able to find one for about $80. complete. Its not rocket science.
 

Roy G

Roy
Senior User
You might try OWWM.org and see if you could find a used switch. They are always selling parts for various machines. You might request the exact switch if you want your machine completely original.

Roy G
 

craftbeerguy

Craft Beer Guy
User
I received a reply from Delta. Their recommendation is A26314S which runs about $229. I like Chris' $80 idea much better. Thanks again everyone for your input and I hope this thread helps others.
 

Houjam s c

New User
Jim
When that switch does go, probably an Asian-made replacement would be suitable for the short term. That switch (technically a magnetic motor starter) has three sets of contacts in case it needs to be wired to a three phase circuit. This means you've got an extra unused set of contacts in there that can be swapped out for a set that's too burned up to use.


For the long term, a good USA-made switch like the ones that used to come on that saw would be nice.


Below, a USA-made 1980s low voltage control mag starter being retrofitted to a 1950s Unisaw.

View attachment 188158
Hello Bob, I'm a new user in South Carolina. I've been following the thread on these switches, and after a bit of a saga I think it's the contacts on my switch assembly that are faulty. Part of the saga was finding (after inspecting the motor and replacing the start and run capacitors) that the dedicated breaker was defective. It was only about a year old. I would love to have a look at the contacts but cannot figure out how to get to them.
The cat. number is 36 815
 

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Dee2

Board of Directors, Vice President
Gene
Staff member
Corporate Member
I only have a cover plate with the buttons circa 1960's-70's
 

HMH

Heath Hendrick
Senior User
I replaced the mag switch on my early 90’s Unisaw earlier this year after moving in, and getting everything dialed back in. Not personally a huge fan of the lesser-quality imports, and found these guys - highly recommended, and not terribly priced - maybe $110 or so if I recall, (3HP). Solid components, and US made, (or assembled at least).
 

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bob vaughan

Bob Vaughan
Senior User
The problem I see with those tiny contact starters is that the contacts become a constriction point, On startup, a motor draws three to five times the rated motor amperage. This constriction leads to burned out capacitors from current starvation during that crucial motor startup time. On shut down, those contacts arc as they disconnect. The heavy current draw causes the tiny contacts to erode faster than larger contacts would. A starter with under sized contacts is a built in device for machine failure. The user gets tired of the constant motor hassle and buys another machine with a tiny contact starter.

Thirty or more years ago industrial grade machines came with industrial rated starters. Later, the European-made IEC type starters became popular. They were less expensive and did a pretty good job. Even later, the Asian-made low priced, low quality IEC starter copies started flooding the market and that's what we mostly have today in home workshop grade machines.

There's always the school of thought that one can replace lots of starters and capacitors for the price of one good NEMA size 1 magnetic starter rig.
 

Houjam s c

New User
Jim
I think the failing breaker probably exacerbated the contact burn out. If there are unused contacts in the starter assembly I would like to go that route for now. Problem is I don't know how to disassemble the assembly. I can find 1 screw; removing it loosens the assembly but it doesn't come out of the mounting box. I don't want to force it.
 

Houjam s c

New User
Jim
I replaced the mag switch on my early 90’s Unisaw earlier this year after moving in, and getting everything dialed back in. Not personally a huge fan of the lesser-quality imports, and found these guys - highly recommended, and not terribly priced - maybe $110 or so if I recall, (3HP). Solid components, and US made, (or assembled at least).
Good tip. Elimia is easy to work with and reasonably priced. Got the new mag switch fo about $115, including priority shipping. Two days from Alabama to South Carolina. The Unisaw lives again.
 

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Charles Lent

Charley
Corporate Member
More often than not, dirty contacts in the Stop button are the problem with Unisaws not starting properly. The normally closed contacts of the stop button will either prevent starting when the start button is pushed, or the saw will only start and then continue to run if you hold the start button in. Before tearing into it significantly, use some fine emory cloth to clean the contacts of the Stop button.

Charley
 

HMH

Heath Hendrick
Senior User
Jim - excellent! Glad you’re back in business and it was able to work out for you.
 

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