Help Wiring a 30 HP Toshiba AC Motor - Ian Needs Assistance

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SUMMARY

The discussion focuses on wiring a 30 HP Toshiba AC motor with dual voltage capabilities (230V and 460V). The user, Ian, seeks assistance in identifying wire numbers after some have been cut and removed. The correct wiring configuration for low voltage involves connecting wires 4, 8, 10, and 2 to supply 1; wires 9, 5, 11, and 3 to supply 2; and wires 6, 7, 12, and 1 to supply 3. A continuity check using an electronic multimeter is recommended to identify the remaining wire numbers based on known connections.

PREREQUISITES
  • Understanding of AC motor wiring configurations
  • Familiarity with Toshiba motor specifications
  • Knowledge of using an electronic multimeter for resistance measurements
  • Basic electrical safety practices when working with high voltage
NEXT STEPS
  • Research how to perform continuity checks on AC motor wiring
  • Learn about proper overload relay sizing for AC motors
  • Study methods for balancing current in three-phase systems
  • Explore troubleshooting techniques for dual voltage AC motors
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Electricians, maintenance technicians, and anyone involved in the repair or installation of industrial AC motors, particularly those working with Toshiba models.

AMGR
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I hope someone can help me.
I have an old 30 HP motor that I need to get working...if possible.
It is a 12 wire Toshiba, dual voltage. 230V 460V.
To wire for the low voltage the nameplate says:
connect wires 4,8,10 and 2 to supply 1.
Wires 9,5,11 and 3 to supply 2 and
Wires 6,7,12 and 1 to supply 3.

Someone has cut the wires and removed some of the numbers. The only identifyible numbers are 4,9,6,8,5 and 7.
Wires 1,2,3,10,11 and 12 have no numbers.

I have an electronic multimeter with resistance measurements.
Is there any way I can check resistances between what I know and what I need to know to identify the remaining wire numbers?

FYI: for high voltage hook-up the wires are paired:
6 and 9.
4 and 7.
8 and 5.
10,2 and L1.
11,3 and L2 and
12,1 and L3.

I appreciate any help.
Ian.
 
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Your 12 leads are for 6 identical coils paired up as
1 , 4
2 , 5
3 , 6
7 ,10
8 , 11
9 , 12
as long as you have 1 side of each coil you can do a simple continuity check to determine the other side and corresponding number. It seems you are in luck.
You have 4 , 5 , 6 , 7 , 8 , 9
if you disconnect all wires from each other, you should check for continuity to the case, If you have none, you can proceed to pair 4 to 1 , 5 to 2, 6 to 3, 7 to 10, 8 to 11, and 9 to 12.

If it were me,once you have them all numbered I would hook it up to a starter and properly size the OLs. If it appears to run fine then I would check for balanced current in each leg.
If they are reasonably balanced you should be ok.
 
Thanks for reply, will go and check what you say right now.
I am normally not that lucky, maybe I should buy a lottery ticket tonight!
 

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