Motor questions

Looking for the vast motor knowledge advice from the forum. I know it is not PLC related but I have always found this forum as the best place for information for anything that has a wire anywhere near it.

My dad came upon from God knows where a single phase motor with a vacuum pump on it. The motor has 5 leads going into a pin and sleave plug labeled T1 - T5. T1-T3 are on one cable going into the plug, T4-T5 are on another cable going into the same plug. From what I could guess T4-T5 might be a vacuum switch of some sort. What I am confused of is why there are 3 other wires on a single phase motor designed for a vaccum pump. The motor is not dual voltage. I have attached name plates for the motor and the pump.

The second motor apparently came out of a golf cart. I have never seen anything like this, the nameplate simply says 12VDC. It has two terminals on it labeled A1 and F1. I can only assume this is a serious wound motor?

Neither of these motors are for mission critical applications, my father is an elderly retired electrician and machinist and is just curious about them, and after looking at them so am I. I thought I knew my motors but these were two things I have never seen before.

Any insight would be appreciated.

The DC motor is surely a series wound motor with the F2-A2 connection probably made up inside the motor. The only problem is that, with this connection scheme, there would be no way to reverse the motor since you reverse both the field and the armature when you reverse the polarity on the A1 and F1 connection. I'm not sure about this. Seems like there should be a third lead unless, of course, the cart doesn't have reverse.

As to the Gast single phase motor, likely it is a split phase single voltage motor with two leads for the start circuit and two leads for the run circuit. The remaining lead is probably ground. But then, the leads would not be labeled that way. My engineering hand book doesn't help on this either. I guess I don't know!

I have never seen anything like this, the nameplate simply says 12VDC. It has two terminals on it labeled A1 and F1. I can only assume this is a serious wound motor?

Click to expand...

Yes, it is a very serious motor with a series-wound contstrution. The hidden terminal is probably the A2,F2 Common, or frame "negative ground" point.

I would say that the dc motor is actually a shunt motor. The armature and field windings are split for the purpose of speed control. A common earth return for both field and armature as Lancie says. Don't know how they achieve reversal of direction though.

Lancie1 said:

Yes, it is a very serious motor with a series-wound contstrution. The hidden terminal is probably the A2,F2 Common, or frame "negative ground" point.

Click to expand...

Lol thanks, sometimes I type faster than I can think. I was sure that was what it was but that didn't make any sense to me in a golf cart as obviously you need reverse. Maybe the old golf carts had some sort of mechanical reversing mechanism.

Ahah!! There's the third connection just as Lancie proposes. F2 and A2 are connected to the frame and reverse is accomplished by reversing the polarity of either the field or the armature but not both. And, yes, it would be a shunt field, not a series (or serious) field. A serious subject tho, don't you think?

If you go to the Gast web site you may find the motor diagram.

Took me a minute to wrap my head around what Lancie said. I get it know, thanks to both of you.

The AC motor connections make sense if you have mistaken T3
for T8. There should not be a T2, I would do a continuity
check between it and ground. If it's a 3 prong plug, T1 & T8
should connect to the L1 plug pin, and T4 & T5 should connect to
the L2 plug pin, ---the third wire to the ground pin of the
plug.

Reverse = L1 > T1&T5 L2 > T4&T8

The DC motor must be SHUNT connected, and non reversible.
If it were a drive motor for a golf cart, it was mechanically
reversed.