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Inactive
Inactive, Master Electrician
Category: Electrical
Satisfied Customers: 4772
Experience:  Electrical Contractor
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How do you get 277 volts from a 480 volt line

Customer Question

How do you get 277 volts from a 480 volt line?
Submitted: 6 years ago.
Category: Electrical
Expert:  Inactive replied 6 years ago.

The Electrical Doctor :

Thank you for asking your question on Just Answer Electrical. You are corresponding with Joseph - "The Electrical Doctor", your personal online electrical consultant.

The Electrical Doctor :

You're question is very important to me, and I will do everything I can to answer your question as thoroughly as possible. Please remember at the conclusion of our time, that you press the "ACCEPT" button as this is the only way I get paid for my time, experience and expertiece.

The Electrical Doctor :

Remember that you can ask as many questions as needed in order for you to fully understand the information given. Dont forget to leave feedback, bonuses are always welcome and appreciated.

The Electrical Doctor :

Please give me a moment to respond to your post:

The Electrical Doctor :

Are you currently working on a project that requires 277v? Also, do you currently have a 480v panel your working from?

Customer :

We supply electronic ballasts for lighting in greenhouses. We are in Canada and here the standard voltage we supply is 347 Volts.

Customer :

For a

Customer :

For a US customer, who currently has 480 volt service, he is asking for lights for his 480 service.Our supplier has said that 277 volts will work and that the electrician should know this.

Customer :

I want to make sure nothing and no one gets fried in the process.

Customer :

So the project is for 277 Volt lights using a service that is at 480 volts coming into the facility.

The Electrical Doctor :

The only way for the customer to get 277 is if he runs one hot and one neutral from the 480v service. In a 480v service, measuring each leg to eachother will give you 480, but if you measure each leg to neutral, you will get 277.

Customer :

OK...so how does a non electrician explain that in terms that an electrician understands....

Customer :

What i guess I am asking is shouldn't this electrician know this?

The Electrical Doctor :

In reality, he should just know this just like I did.

The Electrical Doctor :

Yes

Customer :

Is there a standard manual reference or guide that illustrates this in a text or on a web site that I can refer him to?

The Electrical Doctor :

When telling the customer or the electrician your specs all you need to say is that the ballasts or fixtures run on 277v and they should know the rest from there.

Customer :

That will be my last question and I will hit the accept button if you can provide such a link.....

The Electrical Doctor :

Are you wanting a diagram of how to wire your fixture to a 480v service?

Customer :

Either a diagram or a reference to a diagram.....if that is possible....

The Electrical Doctor :

I can make you a diagram - that is no problem. If you would like me to do that I will. Do you want me to use one of your fixtures to illustrate this? If so I will need a link to your website.

Customer :

www.newlux.com

Customer : [email protected] for the details if they come by email and I am now hitting Accept
Inactive and other Electrical Specialists are ready to help you
Expert:  Inactive replied 6 years ago.
Which light fixture would you like me to use to illustrate the wiring diagram?
Customer: replied 6 years ago.
Any fixture at all would do, the vertical ballast fixture is the actual one being evaluated....
graphic
Expert:  Inactive replied 6 years ago.
Ok, I am currently working on a diagram for the vertical ballast fixture now. I should have it done in about 20 minutes. When I am finished with it, I will post it here for you to see.
Expert:  Inactive replied 6 years ago.
Here is the diagram I made for you. Look it over and if you have any questions, please be sure to let me know.

http://dl.dropbox.com/u/11829262/Just%20Answer/Customer%20Custom%20Diagram/277v%20panel%20wiring%20for%20ballast%20fixture.jpg
Inactive and other Electrical Specialists are ready to help you
Expert:  Inactive replied 6 years ago.
Sorry, I need to update the picture I gave you. I put the wrong color wirinng on it. Please give me a moment to update it.
Expert:  Inactive replied 6 years ago.
Ok it has been updated:

Thank you for "Accepting" my answer and allowing me the opportunity to help you with your electrical question. If you ever need anything further, please dont hesitate to ask. Please remember to BookMark my profile for your next electrical question.


Monday, March 21, 2011 7:09:42 PM
Customer: replied 6 years ago.
Hello Again: re the same matter:
Since you have changed the colors of the wiring, this has added some confusion.
The wiring at the light fixture is white, green and black. This is an approved UL fixture,
277 Volt taking a 750 watt greenhouse bulb.

Which colors go to which colors....?
Expert:  Inactive replied 6 years ago.
Ok that was my fault. You will have brown white and green on the supply side. Then the black / white and green on the load which is your light. So here is how you wire this up:

Brown to black
White to white
Green to green

I can update the picture for you tonight when I get home if you like. Just let me know.
Customer: replied 6 years ago.
Please...when you get to it....no rush...

Expert:  Inactive replied 6 years ago.
No problem.... .
Expert:  Inactive replied 6 years ago.
Ok I have updated your diagram. Click on the link I gave you above and you will have it. Look it over and if you have any questions, please be sure to let me know.
Expert:  Inactive replied 6 years ago.
.
Customer: replied 6 years ago.
Thanks...I consider this all closed now....Is there anything else I need to do to close this as complete>..??
Expert:  Inactive replied 6 years ago.
I will take care of that for you. If you need anything further - please be sure to let me know.
Customer: replied 6 years ago.
Hello again:
I am faced with the same question and a new wrinkle.....
Our 277 Volt lights are to be connected to a power source (480) which is areferred to as a Delta setup with only 3 wires...???
I have no rpoblem in paying an addtional fee as previously paid to get an answer or at elast clarification on this.....
Expert:  Inactive replied 6 years ago.
Ok in this case your not going to be able to do this without the use of a small step down transformer. This would of course be an additonal charge to your customer because they would be responsible for purchasing this themselves, and having it installed in order to do this.

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