Chineese 2 speed 3 phase band saw CY275A.

[Relic]

Have a headache with a CY275A 2 speed band saw..
Has older circuit board J73V2.
Problem is ,4 wires have come off switches on rear of control panel before being dumped in my lap to sort.
All wires are off CN1 on lower connector strip.
Working from left, 3rd,5th,10th and 12th connections.
Fast/slow,stop side of start and left side of e-stop have broken wire ends visable in terminals.
Anyone able to help?
Would be appreciated.

 

[Agroshield]

Wiring schematic in here:

https://images.machineryhouse.com.au/products/B061/PDF/B061%20-%20Instruction%20Manual.pdf

 

[Relic]

Thanks.
Have seen this info.
Board in hand is J73V2.
Different layout of relays and switch wiring.

 

[Relic]

Of note.
Only have board and switch panel to work with.
Owner reluctant to transport whole unit.
Chinese motor label lists 2 speeds at 1.1kw but only one current draw size.
Owner wants overload protection fitted.
Drowning in 2 speed 3 phase problems at moment.

 

[Relic]

Have contacted a couple of suppliers of these units.
Still waiting to hear back.
1-8-24.

 

[Relic]

Progress has been made.
Found a through board joint open.
Examined with my cheap microscope that pairs to my phone.
Small round hole had lost its solder when motor failed.
This means only 2 phases to motor.
Yup, that's why motor cooked.
Put a link in to repair.
Removed 415v to 24v transformer for power supply. .
Soldered wires to diode bridge.
Connected wires to a suitable power supply observing polarity. .
Now could switch between fast and slow speeds.
3 phase unit.
No 3 phase connected to test switching of relays.
Much to my surprise, I couldn't find a star link for high speed on any of the terminals with multimeter on ohms..
Usually control means slow is delta and fast is star/star.
Usually slow means power in one set of 3 leads.
Other 3 leads open.
Fast means the 3 slow leads are connected together (star).
Power is on the other 3 leads.
Windings are connected in double star.
Think delta with center taps which are connected together.
2 of 2 pole relays for each speed on existing board.
Every 3 phase 2 speed encountered so far has 3 of 3 pole relays or contacters.
Considerable time spent trying to understand what's going on.
Gave up and decided to connect recently rewound motor to board.
Refitted transformer.
Connected motor and 415v power supply.
Had a tachometer on shaft when test run.
To my surprise the bloody thing works.
Definitely 2 speeds present.
It appears at this stage, the Chinese know more about electric motor theory than I do.
Cannot wait to get my hands on whole unit to see how it works under load.

 

[Geoffm]

Would have thought a cheap Ali VFD would have been the easiest solution.