[woodnthings]

When I was getting the bloody heck shocked out of me by my dust collector, I researched it on You Tube where I found a simple bare wire connecting the separator to the motor eliminated the shock, no "qualified electrician" was ever needed for static shock.
The OP can try the same thing and see what the results are.
Nothing to lose that trying that either way.

I am using a shopvac based dust collector (the dust cyclone w/ 5 gallon bucket) connected to the table saw via ... PVC pipes! This could be it!

 

[Biotec]

@Karthik

also when testing from the cord and through to the motor it will only test correctly testing
With the motor switch being held in constantly as it is a magnetic latch switch. Which means when it loses power it automatically opens and disconnects to prevent the soft and restarting unexpectedly when being plugged in and or with a power Interruption of any sort.

I said or indicated how long you've had this saw is this a new acquisition or you've had it for a long time and this just a sudden new problem?

Did not say what part of the country you're in and therefore not knowing if you have extreme low humidity problems occurring helping with the shocks I eat static electricity.
These are problems I've seen people complain about more so during the dry winter then during the summer.

Have you tested your saw with no dust collection no connection other than the two power with saw blade all the way down do you notice a static electrical charge? A small shock?

Have you completely clean the saw of all dust especially around in around the motor area and the wiring pathways?

The original saw version of the DeWalt dwe 7491 came out about 20 years ago. On the tag in the upper right corner on the face will be the model number and a date code it could be like this 2021-37-49 means made in the 37th week of 2021 in a chinese plant. 41 USA, 49 and 69 Mexico two different plants, 47, China, 59 Czech Republic and many others

The reason I bring up the date of manufacture is due to there was a spell of wire being made over in the Far East made out of soybean oil and is known to cause bugs and critters and just flat-out wire breakdown over time.

note I added a picture to post #20.

 

[Rebelwork]

Electrician time… we are 42 posts into this. By now with multiple people making multiple posts , if it’s not already figured out, it’s time to make the call..

 

[woodnthings]

With the motor switch being held in constantly as it is a magnetic latch switch.

Are you suggesting this "el cheapo" saw has a magnetic type switch?
That type of switch would cost 1/2 as much as the saw!

 

[FrankC]

Are you suggesting this "el cheapo" saw has a magnetic type switch?
That type of switch would cost 1/2 as much as the saw!

Maybe not bet the farm on that, have seen references to it having one.

 

[Biotec]

@woodnthings

You should know by our interactions that I use in manufacturers labeling for parts whether they match the industry standard names or not. You I have had these discussions multiple times.

The part is labeled as (N603746 Table Saw On-Off Magnetic Switch DeWalt Table Saw, Fits Model DWE7485 DWE7491Rs)

It sells for on Amazon for approximately $16 a few more knock-offs for Less somewhat more on others.

there several types, TYPE of table saw example DWE 7491RS Type 10
also from the manual page 11
Motor Overload and Power Loss Reset Switch If power is interrupted by a circuit breaker trip, or power is lost, the saw contains a power loss reset switch feature that will automatically reset to OFF position.

This is not a magnetic starter assembly or in any shape or form it is just magnetically held in by power so we push the start button it will continue to stay running until you push the stop button or when loss of power occurs as described above a true magnetic switch assembly starter use this overload and thermal protection this does not.

I have a DeWalt dwe7485 type 3. It requires you to push the start button and hold for approximately 2 seconds for it to stay latched then get it switched on.

the wording has changed some manual for this saw is from 2023

Switching On and Off (Fig. A, L)
The on/off assembly 8 of your saw bench offers
multiple advantages:
• No-volt release function: should the power be shut off for
any reason, the switch has to be deliberately reactivated.
• To switch the machine on, press the green start button 40 .
• To switch the machine off, press the red stop button 41

I bought this switch for the router table in Jan 2022.

It is also a type of magnetic switch that automatically shuts down on loss of power to it.
So is intended to prevent unexpected power starts when being plugged in.
...

It is about $30 on Amazon. Comes pre-wired with a male and female cord.

So there are many low-cost magnetic safety switch buttons available on the market.
They are not starters, they are not safety switches in the regard of overcurrent.

Just a two pole start stop button nothing fancy about it.

The intent is for all the line power to end at the switch both the neutral and the hot lead also labeled as black and white.
Line side labeled as (LW) for line neutral and (LB) line black. Note there is no green or ground wire on this type saw
The other side is labeled as (MB) motor black and (MW) motor White
There are two other wires that are attached labeled red and green and follow up to the motor which I do not know where they go as I cannot find a exact reference to what they're used for.....

 

[Biotec]

Using the saw that I have is a Dewalt DWE7485 Type 3 as an example.

When checking all six wires there are no reference to the metal top motor frame all the bare metal.
Indicates that there is no resistance in Meg Ohms.
Another meter I use is a Kline insulation tester

This also showed no line resistance between the black lead Whiteley redley Greenlee to chassis bare metal surfaces. This is a meter the average person who does not do electrical work would have mostly because of cost and it's a specialized application. On average about $160.

The fluke series 23 MI used for testing was over $200 when I bought it over 30 years ago used ones are still selling for over $100 currently. This is also a meter that the average person would not have.
It's replacement is now $300.

There are four wires coming from the motor to the motor switch red and green black and white
Power cord only consists of two wires black and white.

with green button pressed and held With a saw unplugged resistance between the two plug ends is 1.2 to 1.5 ohms of resistance. this is basically the resistance of the motor. Also when turning the blade turn the motor resistance jumped up and down between 1.2 and jumped up to 75 ohms that is the brushes the side of the motor making contact between multiple fields.

This was checked with using a fluke 23 series meter..
this the switch is the saw

It came with and using it as the example.

L is line wire black wire pin 13
N is neutral wire White on pin 34
pin 14 white motor
pin 33 black motor
pin 21 green to motor
pin 22 red to motor.

Pins 21 and 22 are normally closed and therefore red and green are closed circuit. When you push the button to start it opens it stays open until stop is called for.
There is no fixed value for stopping a saw blade here in the United States European Union requires it to be 10 seconds or less and most companies strive for 6 seconds. On power down. Not emergency stop.
So by disconnecting the road or green wire on my saw when powering down it takes much longer to stop versus when the red and green wires are hooked up to the switch as designed. Did not time it nor was I interested in doing so.
This was also done to help the original poster @Karthik and for others who have a similar saw and switch has to be replaced.

 

[Steve Neul]

Basically it comes down to the fact that it is nearly impossible to diagnose the problem without a qualified electrician there in person.

I think he could have told if it was static electricity or actual power by putting a volt meter to the body of the saw. It would have started very small and gone to nothing.

 

[Biotec]

in post #38 I described how to do it if I were doing the work myself.

 

[FrankC]

To the OP, please do not take offence, this is a reply in general and not specific to this thread.

Many times when someone comes here to ask for advice about an electrical problem it is because they have no idea how to proceed, in some cases it is better to advise to get professional help for their own safety.
This is particularly valid when the person offering the advice on how to proceed is not qualified to do so.