Any chance of a circuit of what you have wired ?  - photo of a back of a (large ! ) envelope sketch of the 3 or 6 motor windings  and associated contacts would be fine, and also the make or model of the motor. And, ideally, a photo of the winding ends inside the motor wiring box.

Unless the high low is more of a torque setting than a speed (and on a pool pump torque changing may be what you need) then Star-delta is not the right sort of motor, S-D does not change the speed as such.

For true dual speed the  only kind of motor is  a specially wound one that can be altered to behave in two ways, to change say between say 2 and 4 poles per revolution,  (or 4 and 8) and that involves rather more winding ends in the box  than a normal one.

A normal star-delta always energises the poles at the same rate, it just changes the voltages reaching those windings from 230 during spin up to 400V during run, a true dual speed is something else as the no of poles per rotation is also changed.. A vari-pole motor is not Star-delta, though it looks casually like it and the fast slow switching has much in common.

Even before VFDs were available those were unusual and mainly turned up only in washing machines and at lower powers than this. Nowadays a simple 3 winding motor and  a VFD is more common.

Rare, but it still may be.
The clue is that there are twice as many ends of windings in the box (12 ends not 6 but still 6 terminals) so that pairs of poles may be energized together in the slow speed as one double width pseudo pole and 
slewed between phases in the fast mode. This wiring illustration may explain better. Note there are two approaches, one gives a more or less constant torque at both speeds, and the other a more or less constant power  (high torque at low speed), as when the poles are excited as pairs, they may be // or series. If it is not just  S-D then closer than normal attention to the maker's data may be needed.

Mike.

Any chance of a circuit of what you have wired ?  - photo of a back of a (large ! ) envelope sketch of the 3 or 6 motor windings  and associated contacts would be fine, and also the make or model of the motor. And, ideally, a photo of the winding ends inside the motor wiring box.

Unless the high low is more of a torque setting than a speed (and on a pool pump torque changing may be what you need) then Star-delta is not the right sort of motor, S-D does not change the speed as such.

For true dual speed the  only kind of motor is  a specially wound one that can be altered to behave in two ways, to change say between say 2 and 4 poles per revolution,  (or 4 and 8) and that involves rather more winding ends in the box  than a normal one.

A normal star-delta always energises the poles at the same rate, it just changes the voltages reaching those windings from 230 during spin up to 400V during run, a true dual speed is something else as the no of poles per rotation is also changed.. A vari-pole motor is not Star-delta, though it looks casually like it and the fast slow switching has much in common.

Even before VFDs were available those were unusual and mainly turned up only in washing machines and at lower powers than this. Nowadays a simple 3 winding motor and  a VFD is more common.

Rare, but it still may be.
The clue is that there are twice as many ends of windings in the box (12 ends not 6 but still 6 terminals) so that pairs of poles may be energized together in the slow speed as one double width pseudo pole and 
slewed between phases in the fast mode. This wiring illustration may explain better. Note there are two approaches, one gives a more or less constant torque at both speeds, and the other a more or less constant power  (high torque at low speed), as when the poles are excited as pairs, they may be // or series. If it is not just  S-D then closer than normal attention to the maker's data may be needed.

Mike.