Double delta 230v motor questions.

I have a motor that gets wired double delta for 220 3ph and delta for 440v 3ph. I’ve re wired from 440 to 220 according to the motor plate Along with the control transformer but the motor will not spin up to speed. Thought maybe my RPC could be the issue so for the heck of it I hooked up a vfd directly and it still won’ get up to rpms and rotates slowly and hums loudly same as on the rpc. Lathe was previously hooked up to 480v when inspected. Now I’ve searched far and near to find info on double delta and am not finding much. Motor is 5hp in a Mori Seiki MS850. Now if I take the belts off the motor will spool up no problem. My RPC is made by Kustom Built 5hp and output rating is 15amp 220v. The Mori motor is rated at 13.8 amps at 220v. I do not have any problems with my Milwaukee 2h ,5hp I believe, and 15” Colchester 7-1/2hp although both those have clutches. Now my 24” Invicta shaper 4hp won’t spin up and hums and has a clutch, but works fine with vfd. Now I’ve seen reference for eye start delta run but barely anything for delta delta.

Now secondly is there any issue using a double delta 220v motor for putting together a RPC or is it more advantageous Using the more readily available wye 220v motor. I happen to have another 2 delta motor already.
Thanks Z

Better pic

Measure the resistance L1-L2, L2-L3, L3-L1. They should all be close to even, and probably around a couple of ohms.

Check you have, for certain, every wire in the right group. You haven't shown us the inside of the terminal block?

Maybe I should have led with this as it is all I’ve really found for double delta information.


Double Delta
This method accomplishes the equivalent of reduced voltage starting by changing a delta connected winding from parallel groups to series groups during the start. It is frequently termed "double delta part winding" because it utilizes a standard part winding starter and has characteristics that are similar to the part winding starting. The advantage of double delta is that all of the winding is connected during the start cycle, and the rate of heating is not so severe. This method should be used if possible when the specification is for a double delta winding.

Double Delta Starting

START: L CLOSED, R OPEN
RUN: L & R CLOSED

Double Delta Starting
Staring Characteristics:
Starting current is 60-75% of normal, depending on the specific winding connection.
Starting torque is very low (may not even turn the shaft).
Applications:
Where power system has automatic voltage recovery and normal inrush would cause unacceptable voltage dip. Should not stay on start connection more than 2 to 3 seconds.
Double Delta

The drawings do not load when copy and pasted but the link works properly.
Given this info what actually does the switching between the start and run windings?
Do the double delta motors need a more pure power source?
Rpc had all new caps when I got it but only had run caps between 1-3 so I added run caps between 2-3. Spent plenty of time doing the cap shuffle to get things close. I am putting together another rpc with a 10hp 220v wye connection motor as this current rpc isn’t sufficient for my MG 10ee.
If the double delta is as temperamental as a prom date I can swap it out.

At the moment I’m recovering from hernia surgery so crawling around to check things out will be limited. With the down time I figured I’d inquire.

Z

Here’s info on 9 lead dual voltage double delta.




Phase: 3
Typical Voltage: Dual 230/460
Winding: Double Delta
Special Feature:
Part winding start, low voltage 9 leads
Note: Normally this is a standard double Delta dual voltage motor used for part-winding start on low voltage.

SPECIAL INFORMATION REGARDING PART WINDING STARTING
This motor is not designed to fully accelerate when started with the part winding start connection shown on the motor connection diagram. In order to avoid damaging the motor when it is started with the part winding start connection, set timers so that the motor starter switches the motor connection from start to run within two seconds from the time that the motor is initially energized. The motor is not expected to fully accelerate before the motor connection is switched to run, but the momentary operation on the start connection should allow time for automatic voltage regulators on the power system to compensate for voltage dip resulting from the high current draw of the motor during acceleration. Thus, voltage dip in the power system will be minimized through proper use of the part winding start connection. Once the motor has been switched over to the run connection, it will finish accelerating up to full speed.
During the time that the motor is operated on the part winding start connection, it is expected that the motor may be noisier than when operated on the run connection and it is also expected that the line amp unbalance between phases may be approximately 100% to 150%. This is due to the adverse effect of harmonics that result from the unbalanced magnetic circuit on the part winding start connection.
For further information regarding characteristics of polyphase induction motors when operated on a part winding start connection, refer to NEMA Publication MG 1-1998 Part 14.3

In both cases of the six lead and 9 lead motor schematics I would assume, dangerous word, that I would need some sort of external switching to get this motor to run properly on 220v. Since it was originally wired for 480v and has just your standard reversing switching relay it’s only going to work for 480v And not 220v. So I’d have to either add additional relays for the start run circuit or swap out to a wye 220v motor.
Am I on the right track or just spewing out nonsense?
Thanks Z

So, what you're looking at is a form of reduced voltage starting, similar to a star/delta start but at 50% voltage instead of 57%.

That means it'll draw a lot less current (I think 25%, each winding seeing 50% of normal and series vs parallel), but also develop a lot less torque (25% of starting torque, as starting torque is proportional to winding current squared). This is good if you have too weak a power supply (like an RPC), or you're worried about snapping shafts/belts with a high inertia load. It's bad if your load needs a lot of breakaway torque.

You would need a second contactor and a timer.

If you're using a VFD, you want to just connect it for 240V and let the VFD handle starting. If you have issues with that, your issues are likely inside the motor or machine.

Can you measure the resistance of each winding, and the current and voltage on each leg while trying to start?

I had checked resistance between legs and got 1.2, 1.2, 1.1 ohms. I probably won’t check voltage and amps as I need to hook things back up and probably won’t get back to it for a while as I’m going to be moving. The vfd I used to check it out is a Toshiba 10hp 3ph input that I ran off of 220v single phase but had similar results where the motor didn’t want to spin up. As I use this Vfd for testing purposes I also put it on my K&T 2h and 24” Invicta shaper to make sure I didn’t have any issues with it
Thanks for the input Z