When you engage the contactor, the third blade (we'll call it "power") is engaged and the short between common and control is disengaged. Thus if your device is a simple motor like the snowblower you connect the motor to power and common and ignore control.
If you have a mower deck you could do this too, however the problem is the mower blades will spin for a long time after you cut the power (as they spin down). This is bad. Thus the mower is wired so one pole from each motor is wired to common, and the other is wired to both power *and* control. Thus when the contactor is on, the motors get power and control does nothing. When you turn the contactor off, the motors are basically shorted (being connected now to common and control which as descrbed above are shorted) and the blades come to a quick stop.
Chris ThompsonG DFO-MPO GC CA wrote:
Hi I am trying to figure out the CKT for the PTO socket on My B-145. Somebody please explain it to me. I think my problem is figuring out why there are three blades on the socket and how the PTO start switch latches contactor. Is the PTO only live when something is attached?Very confused Geof Thompson------------------------------------------------------------------------ _______________________________________________ Elec-trak mailing list Elec-trak cosmos phy tufts edu https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak