Small motor wiring of the drive capacitor

[DAPPH]

oOOERR MUMMY .
Been trying to sort out a wrecked wet wheel water bath gringd stone. Someone has been at it with a bloody gert big soldering iron & melted lots of insulation ..it was dead when I got it . So replaced the power cord with a more sutraable one and slipped a 5 amp fuse inthe plug . Purchased a new 4uF motor drive capacitor to replace the 30 yr old alu can one as suspect that it was the initial cause of the problem ,
Popped it in the protected socket switched it on ...It lives .
Only problem is it was running back wards , yes it is the original makers Swedish 175 watt motor .

I 've had a couple of strokes and four lots of covid , my memory is not as good as it used to be .
Question
If I take the S2 switched capacitor wire out of S" and put it in S1 switched should it run forward

I don't fully follow this ( BELOW ) diagram instructions

 

[Pete.]

Yes it should run the other way. It won't hurt to try anyway.

 

[eddie49]

Post #7 of this thread refers to reversing a cap-start induction motor:

capacitor wiring on brooks motor and elliott progress 2gs.

Hello , im not an electrician by a long way but normally get by without any nasty shocks (always get someone else to switch it on ha ha ).. butme and my mate have got a problem with hos Elliott Progress no2 Paillar Drill .. he got it without a motor, but had a good motor in his garage that we...

www.mig-welding.co.uk

 

[DAPPH]

Well I put the new no polarity 4UF cap on the live side and nothing happened swapped it over yea it lives . Put water in the hopper , set it going , was about to grind a 1 "wood chisel when I realised " OH ******** it , it's running backwards agaqin. Wahhaaa!
. Just for fun I stripped the thing down to the last nut & bolt etc , windings looked nice & clean with no obvious damage but I surmise that part of the main windings has shorted before the secondary winding joint and is why I get some reasonable looking ohms readings .
Be interesting as a roundtuit project to see if I can either locate a similar working motor or discover how to redo the windings and bake it in an oven

 

[eddie49]

Your hand-drawn diagram shows the Run and Start windings in series, but in fact they should be in parallel - as shown in the printed diagram. To reverse direction by changing the polarity of the Start winding w.r.t. the Run winding, you have to swap both ends of the start circuit. The start circuit is a series circuit, consisting of the Start winding, the start capacitor, and the centrifugal switch ( if present ).

 

[DAPPH]

I 'll do a colour drawing tomorrow Eddie ...there is no centrifugal switch. I think the capacitor just does enough phase shift to get the induction motor moving . I cannot change the both ends of the capacitor wiring into the windings just one free end is available to move between live and neutral or are you suggesting something different ?

 

[eddie49]

I do understand that there is only one end of the capacitor wiring available, but the other end of the Start winding should not be in series with the run winding.
A single-phase cap-start induction motor can be powered on with only the Run winding in the circuit, no Start winding and no capacitor. It will just hum, but can be spun-up manually, in either direction. Known as "pulling on the belt".