MOTOR CAPACITOR RATINGS

Multi speed PSC motors. . .

The auxiliary winding is connected across the high speed tap of the main winding. That way, if a lower speed is selected, the volage applied to the auxiliary is also dropped by the proportion of the lower speed tap to the high speed.

I don't want to try to draw any more pictures using punctuation. Did any one get more than the first diagram in the previous post in any logical form? When I go back to read it now, it doesn't line up.

Dave D.

Dave,

I have numerous 3-lead PSC motors that are reversible, so the statement about requiring 4 leads to be reversible, isn't accurate.

For an example, look at some Oriental Motor PSC wiring diagrams. BTW, the OM PSC motors are capable of being run at continuously variable speeds, by using the OM speed control modules.

Some manufacturers utilize a method of changing the value of the capacitance to provide different speeds, as in low-med-high, by using a dual capacitor of 2uF and 4uF (to be able to connect a capacitor value of 2, 4 or 6uF).

WB metalwork> Hey Bill,

You have a 2 phase motor of the first type with two identical windings 90 deg apart. It is optimised for easy reversing and good starting torque ("good" means a bit better than lousy!). The penalty is that it needs a large value run capacitor.

Looking at it drawn with the windings connected to form a Vee, with the capacitor bridging the top open ends of the Vee. Supply to Vee base and LH top gives forward rotation. LH Vee is the main winding, RH Vee is the capacitor phase.

Moving supply high from LH Vee to RH Vee gives mirror image operation. The motor reverses. The RH Vee is now the main winding and the LH Vee is the capacitor phase.

Jim

According to Dave D. via CraftKB.com :

There are certain rules which increase the chances of it being readable:

1) Use a fixed-pitch font (such as Courier), not a proportional pitch font (such as Times Roman or Helvetica or whatever your system offers).

This is because differing systems have different ideas of how much the spacing of different letters varies -- and some systems make it very difficult to use proportional spaced fonts in a newsreader anyway. Remember -- not everyone uses the same computer here.

2) *Never* use tabs -- always use enough space characters to make it fit. This is because different programs (editors, pagers, and newsreaders) may have the tabs set differently. The most common is every eight characters on a fixed-space font. A proportional space font may well be trying for a specific distance (in that font) instead. 3) Make sure that your lines are shorter than 72 characters, so they are less likely to be folded at the end of the lines. This can happen in your own editor creating things, in the news server posting your article, in the receiving news server, or in the newsreader program being used at the recipient's end.

While you are about it -- make sure that each line is ended with a hard return. If your program folded the line for you as you typed in, it *may* be sending it out with each paragraph as a single long line, and the chances of it being mangled more on other systems is greater.

4) Always remember to remind others to switch to a fixed pitch font (with Courier being a good suggestion as it is almost alway available on systems with multiple fonts), or *their* variable pitch setting will distort things anyway.

And yes -- it was mangled when I saw it, and I *always* use a fixed pitch font for newsreading rather than switch back and forth, which is a pain on my system.

Be aware that anyone who quotes your ASCII graphics will probably distort it -- sometimes beyond recognition. :-)

Enjoy, DoN.