T90si Pump Polarity

No.username

Hey folks, im changing out a pump in a triton t90si and when picking the pump up the person in the stores that gave it to me said "brown cable to the front and blue to the back" but on the old pump that i want to take out it is the opposite!! Has anyone changed one out lately that can remember the polarity? The terminals are not marked, but there is a thermo fuse in series with the winding that i was told to put the neutral to! I know the fuse would still break the circuit in the event of over heating but i would have thought it would it should be in series with the live cable!!

Hopefully someone can help me out, thanks!

No.username

Actually, does it even matter? Its not going to go in the wrong direction because both the winding AND stator will Both be mixed up!! Am i correct in saying it will only go in reverse if one or the other is swapped? Its being a while since phase 4 and i dont work on single phase motors at all! Thanks

sparcocars

I'm open to correction on this one but i think the motors in those showers are universal motors with brushes. If the polarity is wrong then the motor will go in reverse. The motor your thinking of in the last post is a single phase induction motor where you just change the polarity on the start or run windings to reverse the motor.

I'd say just connect up the wires to the same terminals as the old one regardless of colour and if its going in reverse then just swap them around.

Bruthal

sparcocars wrote: »

I'm open to correction on this one but i think the motors in those showers are universal motors with brushes. If the polarity is wrong then the motor will go in reverse. The motor your thinking of in the last post is a single phase induction motor where you just change the polarity on the start or run windings to reverse the motor.

No the universal motor is not polarity dependent. If you think about it, with a current reversing 100 times a second, with just 2 wires (single phase), there is no reference.

Just for reference, to reverse them, the connection to the actual brushes has to be reversed, so that the rotor windings are being reversed compared to the stator windings.

Even if they are supplied from DC, reversing the polarity they will still run the same way. Only DC motors with permanent magnets will reverse with DC supplies being reversed.

Bruthal

No.username wrote: »

Actually, does it even matter? Its not going to go in the wrong direction because both the winding AND stator will Both be mixed up!! Am i correct in saying it will only go in reverse if one or the other is swapped? Its being a while since phase 4 and i dont work on single phase motors at all! Thanks

Yes, thats about it. When the current reverses in the rotor, it reverses in the stator at the same instant, so the poles are still the same compared to each other, so reversing the supply to the motor makes no difference.

The commutator still reverses the rotor windings as the rotor rotates, just like in a DC motor.

Reversing the connections to the brushes reverses the rotor with reference to the stator, and this is how they can be reversed, and is how it would be done in a washing machine for example, bringing 4 wires out from the brushes, to enable reverse switching.

Bruthal

No.username wrote: »

Hey folks, im changing out a pump in a triton t90si and when picking the pump up the person in the stores that gave it to me said "brown cable to the front and blue to the back" but on the old pump that i want to take out it is the opposite!! Has anyone changed one out lately that can remember the polarity? The terminals are not marked, but there is a thermo fuse in series with the winding that i was told to put the neutral to! I know the fuse would still break the circuit in the event of over heating but i would have thought it would it should be in series with the live cable!!

Hopefully someone can help me out, thanks!

Connect either way, and it will work fine.

sparcocars

robbie7730 wrote: »

sparcocars wrote: »

I'm open to correction on this one but i think the motors in those showers are universal motors with brushes. If the polarity is wrong then the motor will go in reverse. The motor your thinking of in the last post is a single phase induction motor where you just change the polarity on the start or run windings to reverse the motor.

No the universal motor is not polarity dependent. If you think about it, with a current reversing 100 times a second, with just 2 wires (single phase), there is no reference.

Just for reference, to reverse them, the connection to the actual brushes has to be reversed, so that the rotor windings are being reversed compared to the stator windings.

Even if they are supplied from DC, reversing the polarity they will still run the same way. Only DC motors with permanent magnets will reverse with DC supplies being reversed.

Ah yes i know what you mean robbie. I'm still an apprentice myself so still learning. Thanks

ft9

sparcocars wrote: »

Ah yes i know what you mean robbie. I'm still an apprentice myself so still learning. Thanks

You will still be learning when your qualified.

When you know it all its time to give up.

Bruthal

ft9 wrote: »

You will still be learning when your qualified.

When you know it all its time to give up.

Indeed, i see myself as a 25th year apprentice. It never really ends during the active years.

No.username

Thanks Robbie, you're right it wasnt polarity sensitive i tried it both ways and it worked. Im just surprised you still remember that sh1t twenty-odd years later and I can barely remember it 2 years later

Thanks again.