×
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

Switched Power Cord for 120VAC motor?

Switched Power Cord for 120VAC motor?

Switched Power Cord for 120VAC motor?

(OP)
We have a fan we're building that uses a 3/4HP 120V motor.  I'm trying to source a grounding power cord that I can use with an inline switch, but haven't had much luck. I'm wondering if my lack of success is due to something in the NEC that may advise against it.  

Any thoughts?  Thanks in advance guys,
~M

RE: Switched Power Cord for 120VAC motor?

I can't remember seeing anything factory made. There used to be inline switches available for field installation in cords. I doubt that you will find one that is horsepower rated and you may have dificulty finding one that will accomodate #14 cable. (#14 would be the minimum size under Canadian code.)
You may have to go to a toggle switch in an "FS" box with cable glands in the threaded hubs.
respectfully

RE: Switched Power Cord for 120VAC motor?

There are plenty of extension cords with molded-in switches but nobody rates them for HP loads, so you are going to be on your own. The largest one I found with Google was 10A, but that is undoubtedly a resistive load rating. Inductive loads such as motors have starting surges and more arcing when you open the switch, so you need some serious derating to be safe. I wouldn't use that 10A switch on anything bigger than 5A inductive, which at 120V equates to about 1/2HP max, maybe 1/3HP conservatively.

Build your own. Get a good cast box with threaded hubs top and bottom, some good "CGB" style cord grips and a HP rated toggle switch with an cast cover to protect it. Any decent electrical distributor can hook you up.

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