×
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

Single phase test for switchgear

Single phase test for switchgear

Single phase test for switchgear

(OP)
I have a question about the single phase test according to ANSI 37.55- 5.9.1.2 chapiter. My test will be make for 50kA short current, 2 sec. and for 130kA peak current, 10 cycles (60Hz).I like to know how to do this test? What about the electrical connection and ground bus size.My ground bus is a cooper cable gauge 4.0 bolted to a cooper plate (2"x 1/4"). The cooper plate is bolted to switchgear floor.
 What will be temperature rise of cooper and what is mechanical stress?

Thanks for your help.

RE: Single phase test for switchgear

What is the purpose of this test?  I don't have that ANSI std handy but it sounds more like a factory test.
Are you trying verify integrity after installation?  A ductor test of the bolted connections andt then a megger test of the assembly should accomplish that.

wbd

RE: Single phase test for switchgear

(OP)
Thanks wbd,
The purpose of this test is to check mecanical stress of the ground bus and switchgear assembly.It is a ANSI conformance test (type test) for  metal-clad switchgear.A megger test of the assembly does not accomplish that. The current for this test must be rated short-time current for switchgear assembly,in my case it is 50kA.I don't know where I should be make short-circuits in the switchgear. Is there someone in the forum who already is done this type of test? Thanks,


RE: Single phase test for switchgear

I have not done such a test. UL usual did these tests for us on overload relays. Granted they were not quite as high of currents but close. I guess they would use a step down transformer with large gauge wire to source that kind of current for short durations. The trick is to get one with large gauge wire so it does not evaporate when that kind of current goes through it. I don't even know where to look for such an animal, just taking a guess as to how they do it. Good luck. Oh by the way 'cooper' is spelled 'copper'.

RE: Single phase test for switchgear


Minor aside...  One way to conduct short-interval high-current testing is with a massively braced motor-generator set with requisite flywheel.  www.bussmann.com/services/gubany/ Now that’s my idea of superior blood-and-guts entertainment.
  
I think Ferraz may have a roughly similar arrangement in Europe.  [Italy?]
  

RE: Single phase test for switchgear

Rent a Circuit Breaker tester you should be able to find one with that cap.,

Electrical Power Solutions Ltd.
www.e-p-solutions.com

RE: Single phase test for switchgear

A C/B tester may put out 50kA, but only through a very low impedance (the closed contacts of a C/B). The buswork of a switchboard will have a higher impedance and will limit the current significantly. In any case, the fault current will not be backed by the rated voltage which is what the test requires. I believe this test can only be accomplished with LARGE equipment, and is typically done by switchgear manufacturers.

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