×
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

Square D PH MCCB Instantaneous Trip

Square D PH MCCB Instantaneous Trip

Square D PH MCCB Instantaneous Trip

(OP)
Hello,

I have a Square D PH MCCB (1200A)and can not locate what the instantaneous trip value is. Typically on most breakers it would be a dial(s) located on the front of the breaker. There is nothing on the front. The manual discusses installing trip columns (rating plugs) and the TCC shows a range of instantaneous trip.
Does anyone have any experience with this breaker and can point me to where the instantaneous trip setting is located? Is it behind the plate that is removed to install trip columns?

Thank you in advance for reading/replying.

RE: Square D PH MCCB Instantaneous Trip

It's quite possible the instantaneous is fixed at some value between 8 X and 15 X the nominal current rating . It's readily accessible on the front of the breakers, if adjustable.

Bob

RE: Square D PH MCCB Instantaneous Trip

Is it definitely a breaker and not a moulded case switch, i.e. an MCCB without a tripping unit?

RE: Square D PH MCCB Instantaneous Trip

(OP)
Yes it is an MCCB SQD PHF2036, 2000A frame with 1200A trip. This is the main breaker for a 480V service.

RE: Square D PH MCCB Instantaneous Trip

Typically these CBs have a inst. dial setting behind the cover and below the plug ratings that slides from left to right between LO and HI settings. I am not sure about this specific CB and it's hard to make out from the picture, but what is showing below the center pole trip plug on the frame of the CB that would be sitting behind the cover?

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". – Nikola Tesla

RE: Square D PH MCCB Instantaneous Trip

I just found an old picture. It should be below the center pole trip plug as I suspected. Take a look at the attached photo.

"Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature". – Nikola Tesla

RE: Square D PH MCCB Instantaneous Trip

(OP)
Perfect! I knew someone on this site would have an answer! Many thanks as I am unable to go to the job site and see for myself!

RE: Square D PH MCCB Instantaneous Trip

(OP)
VTer, just noticed your name. Just curious if you are in Vermont? I am.

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