Sioux Bench Grinder Switch ?

[fatboy99]

Our 10" bench grinder at work wont turn off so i removed the switch to check out and it's bad. The present switch has the power and neutral running thrue it (both switched off and on) my coworker say's they cant be wired that way because the motor wont be grounded i showed him the ground wire attached to the motor case and the base so i pulled the switch out of the other grinder in the shop it's wired the same way. His brother is an electrical engineer and say's having it wired that way could cause electrouction if there is a problem with the motor! Has any one else heard of this both grinder's are 110 volt. I didnt get mdl #'s of them i can if needed there older heavy duty model's
Thank's in advance

 

[rsanter]

BS
its a double pole single throw switch
lots of power tool are wired that way

bob

 

[Charles (in GA)]

BS +1 , as long as the green ground is attached to the motor frame and not interrupted by the switch, its ok. Interrupting both the neutral and hot is fine, won't hurt a thing.

Charles

 

[mrb]

BS^12

This is very common, and is actually safer since power will still be disconnected if polarity on the attachment plug (or receptacle) is reversed. Its ok to switch the neutral as long as its disconnected simultaneously with the hot(s).

i love how people who come up with this stuff always have a "brother whos an electrical engineer" (installed a car stereo once)

 

[tfi racing]

An electrical engineer that has had a bench grinder apart?
Don't make me laugh...

 

[Costner]

BS to the nth degree. For the exact reason mrb cited, that is actually a great way to do it. If someone would ever connect it to a receptacle that was wired backwards or if they ever replaced the cord or if they ever used one of those three to two prong adapters while plugging it into a receptacle upside down... the switch will kill both the hot and neutral lines regardless of polarity.

Just to put the electrical engineer thing in perspective, I know one who couldn't figure out how to wire a up/down/stop control on an overhead door. Four years (or more) of schooling can only do so much.

 

[fatboy99]

This guy work's for a company that's makes machines to build electric motor part's he spend's lot's of time in China showing them how to steal our job's !

I knrew it was BS but you cant tell these two ANYTHING they know it all !!!

MRB I figured they wired them that way because these grinder's were built long before the plug's were made to only be pluged in 1 way.

 

[Torque1st]

MRB I figured they wired them that way because these grinder's were built ling before the plug's were made to only be pluged in 1 way.

More likely they just use the same switch for 220V models.

 

[Charles (in GA)]

More likely they just use the same switch for 220V models.

I didn't, but was going to suggest that on motors that can be converted to 240v by swapping jumpers in the motor (like my 1 hp Craftsman compressor from the 1970's) that the double pole switch would be a necessity. (my compressor did not come with a switch, I added a dp motor rated switch to it several years ago).

Charles