How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask ProGrade Your Own Question
ProGrade, Certified Electrical Contractor
Category: Electrical
Satisfied Customers: 541
Experience:  28+ years exp. - installation, troubleshooting, & repair of commercial, & residential electrical systems.
Type Your Electrical Question Here...
ProGrade is online now
A new question is answered every 9 seconds

I have a 20 hp hyundai dual voltage 240/480 3 phase motor im

Customer Question

I have a 20 hp hyundai dual voltage 240/480 3 phase motor im wiring up. It has 2 different diagrams for the wiring on it---it has a low voltage "start" configuration--a low voltage "run " configuration...and the same for high voltage. i am wiring for low voltage, but not sure which configuration to use--the " start" or the "run" I have wired many 3 phase motors just not sure on this one with 4 possible configurations?
JA: Sometimes electrical issues that that you think will be really complicated end up being easy to fix. The Electrician I'm going to connect you with knows all the tricks and shortcuts.
Customer: oh--its sismple--just need to know which diagram to use
JA: Do you plan on doing the work yourself?
Customer: yes
JA: Anything else we should know to help you best?
Customer: no
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Electrician about your situation and then connect you two.
Submitted: 1 year ago.
Category: Electrical
Customer: replied 1 year ago.
Customer: replied 1 year ago.
I attached the diagram that I have with the motor--just need to know which one to use for low voltage
Expert:  ProGrade replied 1 year ago.


Welcome to
Do you have a motor starter?

In most areas, reduced voltage starting is required for all motors 5 HP or larger, 7.5 HP in some areas. If this method were not used, voltage drops large enough to be noticed and cause problems would occur.
A star-delta starter has the wiring diagram for the connections.
Another, more expensive option is a VFD (variable frequency drive).

Contemporary star-delta starters are generally automatic. You used to be able to find manual starters of this type. You would pull the handle until the motor was up to speed, sometimes indicated with lights on the starter, sometimes by the sound of the motor, then push the handle to the run position.

Let me know if you have any other questions or need help selecting a starter.


Customer: replied 1 year ago.
you didn't answer my question at all--I already figured it out as I needed an answer 24 hours ago and was supposed to have an answer within minutes or a day.
Expert:  ProGrade replied 1 year ago.
Hey, you are the man, your words are so kind & gracious. I hope you have a great day! Hope all of the best with your project. Do unto others....
Expert:  ProGrade replied 1 year ago.
let me know if you have any questions. I will be glad to provide further assistance if you have a or decide to get a starter. Thanks