×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

New motor blowing fuses
2

New motor blowing fuses

New motor blowing fuses

(OP)
I recently bought a 2hp. 110/220 V. motor made by Kohlbach in Brasil.  The motor has 7 wires.  the wire up info plate states the following.  Wires 1&5. go together and are hooked to one side of 220V.  Wire 4 goes to the other side of 220V.  wich leaves wires 3,6 and 2 which are tied together, lastly wire 7 is left.  I WAS TOLD, wire 7 goes to ground and 3,6&2 are just bound together with a Marrett insulator.  I have followed all instructions to the letter, However when I turn the motor on it always blows a fuse on one side of the 220.V. line I have 20Amp. time delay fuses and still it blows. The strange thing is the motor runs after it has blown the fuse so therefore must only be running on 110 V.  I am baffled and would appreciate any help.  Thanks.

RE: New motor blowing fuses

Hello Brycol

I would check to see if wire 7 is internally connected to the windings. If this is the case, then I would definietly not connect it to ground!
It is possible that this wire is internally connected to the windings and you are creating another circuit path via earth. This would not be a problem if the motor was the only appliance connected to a floating system, but if there is an earth elsewhere on the system, you could have a return path.

Best regards,

Mark Empson
http://www.lmphotonics.com

RE: New motor blowing fuses

I too have encounterd situations where the directions are somehow wrong. Take the motor apart and trace out how all of the wires are connected.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources