2 speed star delta motors

[paul wild]

Hi guys,
would anyone have any info on 2 speed star delta motors
the one I'm looking at has a selector switch on control panel for low speed this brings in one contactor
when you rotate the switch from low speed through off position to high speed position it drops out the low speed contactor as the switch goes to the off position and brings in the other 2 contactors when selecting high speed
I'm just wanting to find out more about this set up
cheers
Paul

 

[Pete999]

Think you may need to rethink Paul, there is no such thing as a Star Delta motor, not had much to do with speed control regarding squirrel cage machines, try googeling Brooks control gear they may have something that you could use

 

[paul wild]

Sorry should have said star delta stater set up to run motor in 2 speeds via selector switch ?

 

[Pete999]

That's OK mate wasn't trying to sound clever, you wouldn't want speed control when starting the machine in the star configuration, the only speed control I've seen is the wound rotor set up, after the machine has swapped to delta, but that was a long time ago, sorry can't help mate maybe some of the other guys can, good luck.

 

[paul wild]

Thanks for the reply
many thanks

 

[Marvo]

I'm a bit cvonfused by your question, are you talking about a Dahlander motor?

 

[Darkwood]

Try looking up consequent pole speed control... you can have various options here depending on requirements.

Constant Torque - Torque the same high and low
Constant Horse power - HP same both high and low
Variable torque - these have a torque proportional to to the speed

The latter im familiar with on some of the Russian lathes i do maintenance for.

I believe that the pics kindly shown by Marvo are of this type Variable Torque option.

 

[paul wild]

Sorry for being so vague on this one guys,
here is what I have
one motor 6 wires
2 supply's one supply's contactor for low speed and the other does high speed
the contractor on load speed works independent of the other 2 which work on high speed
their is a timer also in the circuit
so to clarify one supply and contactor for low speed
another supply and 2 contactors and timer for high speed
the problem I have is that the motor keeps going out on overload on high speed
and recently also has been taking out the MCB on high speed
hope this info helps what kind of set I have here
cheers
Paul

 

[paul wild]

Should also say guys
on load speed unit draws 9.1 amps per phase
on high speed unit draws 21 amps per phase
cheers
paul

 

[Darkwood]

give all plate details kw etc your info means nothing ... what is the motor doing - duty wise ... what machine is it in ... is this a recent problem ... is it driving gearing with clutch control ... the list of questions is endless give us as much as poss about what it does and the history of it .

 

[Marvo]

here is what I have one motor 6 wires

Are there any kind of labels or identification on the wires from the motor? If so can you say how they're labeled?

 

[paul wild]

Here are some data plate photos and the motor connections if this helps
the motor is on a air handling unit
Motor drives a belt and runs free
has been causing trouble for about last 8 months going out on over load
cheers
paul

 

[Darkwood]

This is not the setup you described ... it a star/starstar 2 speed motor ... im ratarsed at mo will look tomorrow but not uncommon... its easy to prove the motor usually an external reason will be your issue ...

but is a variable torque motor ...ie..soeed option proportional to torque ... usually on the controls of machine it will express the 2 ratings it can deliver ..

 

[Marvo]

Yep it's definitely a true 2-speed motor and with the low speed being half of the high speed there's a good chance both windings are in Dahlander arrangement. To be sure you'd need to contact the company with the model number and they'd tell you over the phone.

VEM are good motors, I've come across a few of them. Here's what I have on them.

View attachment VEM Motor specs.pdf

 

[paul wild]

Thanks for all your input guys