Potter & Brumfield Magnetic Switch?

[John]

I bought a table saw that I want to change to 240v.

As nearly as I can figure, the power cord goes to a Square D pull out switch
(FP222R). From there it goes to a large Reitech momentary contact switch
(EZO-MS), and then to a Potter&Brumfield device of some sort, and then to
the motor. Unfortunately the part number is rubbed off the P&B device, but
it is a coil with some contacts on it, so I presume it is a magnetic switch.
I can make out 120v, so I am guessing it only good for 120v.

A picture of it is at http://www.frontiernet.net/~toller/switch.htm

Is this guess likely correct? How would I go about changing to one capable
of handling 240v?
If someone is familiar with Potter & Brumfield switches, I would be grateful
for your help.

 

[George M. Kazaka]

Most Mag switches run on 110/120 volts even if you are using 240.
Even my 3 phase equipment that has mag starters are only on a 110 leg.
There should be a wiring diagram inside the cover, to tell you how to wire
it,

 

[John]

You're going to need some adult supervision on this. As in other messages,
the coil has to be 120V if the tool was running on 120V before. You have to
be sure you are switching both hot leads and that the coil runs from one hot
to neutral.

I don't think you need a fourth wire, but code may ask for it. It's up to
you. Mine are all on 3 wire plugs.

I think talking you through this is more trouble than it's worth, unless you
find and can understand the schematic. Someone knowledgeable can do it in
five minutes. Don't you have any electrically oriented friends??

I have identified the part as a PM-17AY-120. The manufacturer suggests
replacing it with a PM-17AY-240 for $90. That is a little out of my budget.

I haven't managed a schematic on it, but this is a catalog page on it.
http://www.sourceresearch.com/potter/pdf/pm_dsw.pdf

Any chance of making this work? Any way to get the schematic?

Thanks.

 

[John]

Read the coil data chart. It says to use a 2700 to 3300 5w resistor in series
with the coil. (for 220v operation) Is there an echo in here ;-)

From the other comments you have received about following the connection
instructions from the manufacturer of the saw that resistor may already be
there somewhere.

I read it that way the first time also, but I am pretty sure the resistor is
to change 120vdc to 220vdc. I would like to be wrong about this, but that's
how it looks to me. I expect a resistor is less than $90!
Do you think they mean 120vac to 220vac??!