Woodturning (rec.crafts.woodturning) To discuss tools, techniques, styles, materials, shows and competitions, education and educational materials related to woodturning. All skill levels are welcome, from art turners to production turners, beginners to masters.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 29
Default wireing problem

I just purchased a 3/4 HP vacuum pump and would like to hard wire it up to
220V power. The shock came when the big box stores don't sell double pole
single throw (DPST) switches and Grainger's motor starters start over $100.
I can always leave it at 120V, but there must be a better way! Anyone know
where I can get a 220V switch for $15? Now I am a chemist, not an
electrician. I assume that I need a double pole switch. Is that correct?

Second question: All of the rigs I have seen for vacuum chucks are, shall
we say, not quick change insulations. To change to a spur drive and the
knock out associated with that drive requires dismantling the vacuum
apparatus. My lathe is a PM 3520. Does anyone have a quick change plan
that could be adapted to this lathe?


  #2   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 203
Default wireing problem


"Paul Gilbert" wrote: (clip) I assume that I need a double pole switch.
Is that correct?
^^^^^^^^^^^^^^^^^^^^^
Correct. I have a printing press with two motors--each is controlled by a
single throw, double pole switch. That suggests to me that these switches
must be available as parts for various kinds of shop and industrial
equipment. You could even use a knife switch of the type used in your meter
box.


  #3   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 1
Default wireing problem

In article ,
"Paul Gilbert" wrote:

I just purchased a 3/4 HP vacuum pump and would like to hard wire it up to
220V power. The shock came when the big box stores don't sell double pole
single throw (DPST) switches and Grainger's motor starters start over $100.
I can always leave it at 120V, but there must be a better way! Anyone know
where I can get a 220V switch for $15? Now I am a chemist, not an
electrician. I assume that I need a double pole switch. Is that correct?

Second question: All of the rigs I have seen for vacuum chucks are, shall
we say, not quick change insulations. To change to a spur drive and the
knock out associated with that drive requires dismantling the vacuum
apparatus. My lathe is a PM 3520. Does anyone have a quick change plan
that could be adapted to this lathe?


Check an electrical supply store. Or online, or maybe Radio Shack
  #4   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 64
Default wireing problem

In article ,
Dan wrote:

In article ,
"Paul Gilbert" wrote:

I just purchased a 3/4 HP vacuum pump and would like to hard wire it up to
220V power. The shock came when the big box stores don't sell double pole
single throw (DPST) switches and Grainger's motor starters start over $100.
I can always leave it at 120V, but there must be a better way! Anyone know
where I can get a 220V switch for $15? Now I am a chemist, not an
electrician. I assume that I need a double pole switch. Is that correct?


DPST 250V returns plenty of options (google search)

Not the cheapest, but with good motor ratings well above what you want to run
(safety factor)

http://www.pressureparts.com/Pressure-Part-337205.aspx

Cheaper by far, and adequate for your horsepower rating (beware of link wrap):

http://www.newark.com/arcolectric-sw...pst/dp/92B3802

DPDT 250V adds a few more - you can ignore the second throw.

250 tends to be the rated voltage, rather than 220, so that may help your
search.

--
Cats, coffee, chocolate...vices to live by
  #5   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 6,375
Default wireing problem

In article , "Paul Gilbert" wrote:
I just purchased a 3/4 HP vacuum pump and would like to hard wire it up to
220V power. The shock came when the big box stores don't sell double pole
single throw (DPST) switches


Yes, they do. You're just not looking in the right place. Really.

I can always leave it at 120V, but there must be a better way! Anyone know
where I can get a 220V switch for $15?


Lowe's, Home Depot, Menards, Ace Hardware, Tru-Value Hardware, Do-It-Best
Hardware... you get the idea, I'm sure.

Example:
http://www.lowes.
com/lowes/lkn?action=productDetail&productId=70625-334-1245-1V-SP-L

Now I am a chemist, not an
electrician. I assume that I need a double pole switch. Is that correct?


That is correct.


  #6   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 943
Default wireing problem


"Doug Miller" wrote in message
news
In article , "Paul Gilbert"
wrote:
I just purchased a 3/4 HP vacuum pump and would like to hard wire it up to
220V power. The shock came when the big box stores don't sell double pole
single throw (DPST) switches


Yes, they do. You're just not looking in the right place. Really.

I can always leave it at 120V, but there must be a better way! Anyone
know
where I can get a 220V switch for $15?


Lowe's, Home Depot, Menards, Ace Hardware, Tru-Value Hardware, Do-It-Best
Hardware... you get the idea, I'm sure.

Example:
http://www.lowes.
com/lowes/lkn?action=productDetail&productId=70625-334-1245-1V-SP-L

Now I am a chemist, not an
electrician. I assume that I need a double pole switch. Is that correct?


That is correct.


actually, a single pole switch will work, but one side will stay live all
the time so a double pole single throw switch is preferred - widely
available - get a motor rated switch and do NOT go to radio shack for it.

for vac info, DL the article from my web page - it will give you some hints


  #7   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 203
Default wireing problem


"Bill Noble" wrote: (clip) do NOT go to radio shack for it.
^^^^^^^^^^^^^^^^^
There is a good chance that the clerk at Radio Shack won't know what it is.

One good reason, besides safety, not to use a single pole switch, even
though it will turn the motor on and off, is that a double pole switch is
much better at suppressing arcing. This is an issue on inductive loads like
motors.


  #8   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 6,375
Default wireing problem

In article , "Bill Noble" wrote:

actually, a single pole switch will work,


"Work" in the sense that it will stop the device from operating. But not
safely...

but one side will stay live all the time


... for exactly that reason.

so a double pole single throw switch is preferred


If by "preferred" you mean "required for safe operation" then I will not
disagree with you.
  #9   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 943
Default wireing problem

note that the "one side live all the time" is pretty much unique to the USA,
whose standard 220 is really based on a grounded center tap neutral - most
other countries have a 220 that has a neutral leg and the hot leg is 220
above it, and the neutral is nominally at ground. So, in some other
country - say the UK, a single pole switch on the hot lead would eliminate
any "live" voltage past the switch.


"Doug Miller" wrote in message
...
In article , "Bill Noble"
wrote:

actually, a single pole switch will work,


"Work" in the sense that it will stop the device from operating. But not
safely...

but one side will stay live all the time


.. for exactly that reason.

so a double pole single throw switch is preferred


If by "preferred" you mean "required for safe operation" then I will not
disagree with you.



  #10   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 203
Default wireing problem


"Bill Noble" wrote in message
...
note that the "one side live all the time" is pretty much unique to the
USA, whose standard 220 is really based on a grounded center tap neutral -
most other countries have a 220 that has a neutral leg and the hot leg is
220 above it, and the neutral is nominally at ground. So, in some other
country - say the UK, a single pole switch on the hot lead would eliminate
any "live" voltage past the switch.

^^^^^^^^^^^^^^^^^^^^
And your point is? Since this is the only place in the world where a two
pole switch is needed, it must be only a technicality. This is the only
place in the world where you can be electrocuted by a technicality.




  #11   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 943
Default wireing problem


"Bill Noble" wrote in message
...
note that the "one side live all the time" is pretty much unique to the
USA, whose standard 220 is really based on a grounded center tap neutral -
most other countries have a 220 that has a neutral leg and the hot leg is
220 above it, and the neutral is nominally at ground. So, in some other
country - say the UK, a single pole switch on the hot lead would eliminate
any "live" voltage past the switch.


"Doug Miller" wrote in message
...
In article , "Bill Noble"
wrote:

actually, a single pole switch will work,


"Work" in the sense that it will stop the device from operating. But not
safely...

but one side will stay live all the time


.. for exactly that reason.

so a double pole single throw switch is preferred


If by "preferred" you mean "required for safe operation" then I will not
disagree with you.




aaah, no, my point was that in my experience that there are other countries
in the world, and that sometimes residents of those other countries might
read this news group, and that it is only common courtesy to suggest how a
discussion that is unique to the peculiar way the USA does things might
differ if it were applied to their situation. Because of our lawyer rich
society, I have offered no opinion on the safety or legality of any switch
configuration, I have merely offered specific information on the way that
power is supplied world wide and how a motor might possibly be controlled by
a device capable of interupting said power. Any application to actual
electricity is at the risk of whomever elects to be in the presence of said
electricity. Many countries have recommended configurations for such
devices. Some countries even have laws and regulations governing the
employment and application of such devices. It would be incumbent upon the
user to establish saftey, legality, permitting, and to comply with all
local, national, international, galactic, and intergalactic regulations that
might possibly apply to their situation and to make said determination after
proper consultaion with those fully authorized and empowered to supply said
determination.

I hope that the above elucidates my position with respect to possible
confgurations of power supplies and the means that one could in theory use
to supply or interrupt them.


  #12   Report Post  
Posted to rec.crafts.woodturning
external usenet poster
 
Posts: 6,375
Default wireing problem

In article , "Bill Noble" wrote:
note that the "one side live all the time" is pretty much unique to the USA,


I'm sure that's news to thousands of electricians in Canada and Mexico.

whose standard 220 is really based on a grounded center tap neutral - most
other countries have a 220 that has a neutral leg and the hot leg is 220
above it, and the neutral is nominally at ground. So, in some other
country - say the UK, a single pole switch on the hot lead would eliminate
any "live" voltage past the switch.


True, but irrelevant. If the OP had been located in the UK, he would not have
been looking for a DP switch to disconnect a 240V load. The fact that he *was*
shows that he's located somewhere in North America.
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
basic wireing [email protected] Home Repair 5 March 11th 08 12:12 PM
Colours of 1950s wireing. Dave Fawthrop UK diy 28 December 19th 06 12:47 AM
Aluminum Wireing Born2 Home Repair 15 September 6th 06 06:41 PM
Potterton EP3002 wireing diagram Simon Coupland UK diy 3 September 4th 06 10:54 PM
Wireing a duct fan into a basic US 110V outlet [email protected] Home Repair 5 January 14th 06 01:57 AM


All times are GMT +1. The time now is 06:52 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"