Need Help!- Wiring Slo-Syn 240V 1 Phase Motors

[PerPlexed]

Hi All,

I have just acquired several Slo-Syn SS92 240V 1 Phase Synchronous motors and am a little perplexed to wiring them up. First off, they have a built in terminal block with 7 pins labeled A-H, left to right from the back.

I am using these in an automated wood mortiser/tenoner which I'm building. This is not CNC, it's automated with microswitches, etc... I'm looking to set the switches in the machine is such a way that they can be adjusted for various widths, heights and depths. One will fire the next, will fire the next in a continuous pattern until the operator overrides the cutting action.

These switches need to fire the CW and CCW directions of the motors as required. A 120V 1 Phase would be a simple wire job but I'm not too sure what to do with the 7 pins on the terminal block. I feel one pin is Chassis ground? and I feel the other 6 are actually 2 separate circuits for CW and CCW directionals? Of these circuits, one would be common, one L1 and one L2?

Danaher's (Superior Electric distributor) web site has a wiring diagram for a newer version of this motor, the KS092. It shows 2 lines coming in. One common (the motor's white wire anyway) attached to leg 2 of the motor. The other AC line attaches to a switch to control CW and CCW motion by either directing the voltage to leg 1 or leg 3 via red and black wires respectively. There is then a capacitor and a resistor (customer supplied) in parallel with these two wires. This looks like a 120V, 1 phase wire up to me. Maybe I just don't understand something here.

Am I going down the right road or am I all washed up? How do I wire these motors?

Thanks in advance for any help.
PerPlexed in WV

[Al_The_Man]

Did you measure the continuity on the connector to find out if they are all connected.
You have AC synchronous stepper motors, and you need the capacitor to run them, the capacitor/resistor is in series with one winding.
On 60hz they will run at 72rpm usually.
Al.

[PerPlexed]

Hi Al,

Thanks for the reply. No I haven't checked continuity. What should I be looking for and what do the results mean?

Thank you
PerPlexed in WV

[Al_The_Man]

They often have the multi pin connector as used in the DC stepper motor version, on the AC version they are not always all used.
Look for a two readings with a centre tap or two distinct windings.
Al.

[PerPlexed]

Hi AL,

I took one of these motors apart, effectively ruining it of course. But, I found that three of the pins were connected and the others are not. Inside I found 8 separated stator windings and the rotor of course is a permanent magnet rotor. One pin on the terminal block energizes all eight windings. The second pin energizes four (obviously 90 degrees from one another) and the third energizes the other four windings.

With what little info I could gather, it appears pin one would be connected to L1. L2 would then need to be split into two lines and the phase shifting components of a resistor and capacitor will be connect between these two lines in parallel.

To run this motor in a CW motion, the line on the resistor side of the L2 would be energized, CCW the capacitor side if L2 would be energized. Keep in mind this is a parallel installation of the phase shifting components. By the way, the instructions I have located indicate a 2000ohm, 25W resistor and a .75mf, 370VAC capacitor are to be used. I have located and ordered these items with the capacitor being a motor start capacitor.

My questions NOW is: Can I set up four of these motors in a parallel configuration by splitting L2, installing the phase shifting components and running the split L2 lines into separate buses in which I pick up the each motor's split L2s and then running these lines through their appropriate switches, etc...???

Normally, only one motor will be running at a time but I have thoughts of overlapping their operations to produce rounded tenons and matching mortises. If there is more than one motor operating off the phase shifted buses, will this cause any issues? Or, will each motor require its own resistor/capacitor phase shifting componentry? For the life of me, I don't see any reason why I cannot run these all off one phase shifted bus.

Please advise your thoughts.
Thank you
PerPlexed

[Al_The_Man]

Setting up the 90deg phase shift via resistor/capacitor requires 'tuning' these components to the matching inductance of the split phase winding, if you start adding inductance (windings) in parallel, it will affect the phase angle of the split phase and current and performance will vary.
The bottom line is you need one set of components for each.
BTW, the capacitor should be a Motor-run style, not motor start, as these are not made for 100% duty cycle.
Al.

[PerPlexed]

Hi Al,

Thank you for the reply. I double checked the manufacturer's installation requirements and doubly confirmed the Slo-Syn SS92 motors require a 2000 ohm resistor and a .75mf 370VAC capacitor so all is good there.

My new question> I wish to set up lamps (pilot lights) on this system to indicate when a microswitch fires. I'm doing this to set the machine up for precise measurements prior to actually cutting wood. I wish to pick up off the phase shifted L2 lines at the microswitches and run them into the 120V neutral for simplicity of set up. My question is, will the resistance of the parallel run lamps alter the phase shift of the L2 lines? I intend to set the lamps, operating switches and microswitches downstream from the phase shifting componentry.

Thank you,
PerPlexed

[Al_The_Man]

What size lamps are you thinking of using? pilot lights are usually very low wattage, one other alternative is Neon lamp indicators, these place no load whatsoever on the circuit.
If incandescent, as long as they are low wattage indicators, it should not affect it.
Al.