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Giles
02-24-2009, 06:12 PM
I have an old, probably 1970s, Dewalt 740 radial arm saw. My on-off switch went bad and I was surprised to find out it is a double poll switch. This switch is not available, so I plan to use a double poll switch for replacement. This is 110v application.
Out of curisoty, why are both the neutral and the hot broken in this application?

jadnashua
02-24-2009, 06:16 PM
Most of the motors used on those tools can be rewired to run on 220vac, so you'd then HAVE to break both leads to remove all power. This is done by moving jumpers in the motor assembly, then replacing the plug or power cord.

Giles
02-24-2009, 07:30 PM
Most of the motors used on those tools can be rewired to run on 220vac, so you'd then HAVE to break both leads to remove all power. This is done by moving jumpers in the motor assembly, then replacing the plug or power cord.

Thanks---I now understand and that makes sense.

Giles
02-26-2009, 11:28 AM
Most of the motors used on those tools can be rewired to run on 220vac, so you'd then HAVE to break both leads to remove all power. This is done by moving jumpers in the motor assembly, then replacing the plug or power cord.

Upon investigaton for replacing the factory switch with a double poll switch, it was discovered that extensive modification will be necessary for a neat application. A single poll switch would be much simpler. It makes sense to me that a single poll switch could serve the purpose of breaking the hot and I could connect the two neutrals. I know this would not work for 220v.
Would this be advisable?

jadnashua
02-26-2009, 12:16 PM
You'd lose the UL certification. If someone tried to change it to 220vac operation, they could be injured. If it generated a fire or injury, your insurance may not pay. Proceed at your own risk.

Giles
02-26-2009, 01:08 PM
Thanks, I will use the double poll

hj
03-01-2009, 02:17 PM
Check the motor plate to see if it is a 120/240 motor. If not then the reason for a two pole switch would be acedemic.