Delta - Wye Switch for 2 speed motor
My Economaster lathe ( Made in Brazil ), has a 2 speed Brooks (Made in Canada). Unfortunatly the switch is long gone, and I would like to repace it.
It is 220v 3PH 5/3 hp 1760/860 Rpm. It is wired for high speed right now. so -PLan A is to find a switch, Plan B is a VFD.
Hopefully Plan A can be more cost effective.
You could always pick up 3 contactors off ebay and set up a Star-Delta switch over that way.
A VFD is a better choice, not only because of wide range speed control, but because it will likely be cheaper unless you find a surplus switch somewhere.
I think Delta-Wye switching is commonly used in the UK and perhaps elsewhere to change the operating voltage of motors. It is also used to reduce starting current of large motors. I do not think it is used to change the number of poles to effect speed changes but it may just be a terminology thing and the same type of switch may be used for speed changing.
Probably an application for a mutiple pole rotary switch. Does it also reverse? Have you asked this question at a motor rebuild place?
The 1600 version of the Colchester Bantam used a two speed too. Maybe there's a Clausing version that did 1600.
I haven't even got my new-to-me Bantam - not two speed - going in reverse yet. I'm running it with a static converter, and the wiring is on-going.
I've kept a look out for two speed motors and switches for a few months now, but I haven't seen anything.
But now I've just googles "Delta-Wye" and it seems it's what we call Delta-Star. That changes the voltage the motor will take, but not the speed - that's pole dependent - just as Don said.
I don't know what the pole switching switches are called. From the Bantam manual, there's a rotary switch called the ESX 1311 PC that seems to be the two-speed switching part.
Last edited by rohart; 02-06-2011 at 09:25 PM.
yes, there is a delta-star (wye) speed change......
It is a delta with center taps.... delta is the low speed, the polarities of the two windings in each arm are such as to be opposed and create extra poles.
For high speed, the connection is to the center taps, and the apexes of the delta are connected for "double" star. That reverses some polarities, which causes the previously reversed windings to add with the others in phase to form fewer bigger poles.
Last edited by J Tiers; 02-06-2011 at 10:02 PM.
That is very interesting and something I had not heard of. There are a lot of motor connection schemes in addition to the common well known ones. Thanks for the info.
Originally Posted by J Tiers