Previous in Forum: electrical engineering   Next in Forum: Neo magnets
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
4 comments
Rate Comments: Nested
marcot
Guru
Canada - Member - Specialized in power electronics

Join Date: Feb 2008
Location: Montreal, Canada.
Posts: 1372
Good Answers: 80

Highpot test on a medium voltage switchgear

06/07/2008 2:28 PM

Dear colleagues,

I have to perform a highpot test on a medium voltage switchgear. From preliminary researches, it is not clear what are the requirements to meet NEC. Simple rules like the "twice rated voltage plus 1KV for one minute" used on low voltage certainly don't apply. What is the recognised test voltage for a 4160V switch?

Thank you for your help.

__________________
 Experienced is earned, common sense is taught, both are rare essentials of life.
Register to Reply
Pathfinder Tags: highpot test medium voltage switchgear
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
ekiechle
Commentator

Join Date: Mar 2008
Location: South Texas - SOMETIMES
Posts: 88
Good Answers: 4
#1

Re: Highpot test on a medium voltage switchgear

06/08/2008 8:32 AM

Here is a table from NETA specs..

Electrical Apparatus Other than Inductive Equipment

Nominal
System (Line)
Voltagea (kV)

Insulation
Class

AC Factory
Test (kV)

Maximum
Field Applied
AC Test (kV)

Maximum
Field Applied
DC Test (kV)

1.2 1.2 10 6.0 8.5
2.4 2.5 15 9.0 12.7
4.8 5.0 19 11.4 16.1
8.3 8.7 26 15.6 22.1
14.4 15.0 34 20.4 28.8
18.0 18.0 40 24.0 33.9
25.0 25.0 50 30.0 42.4
34.5 35.0 70 42.0 59.4
46.0 46.0 95 57.0 80.6
69.0 69.0 140 84.0 118.8

In the absence of consensus standards, the NETA Standards Review Council suggests the above representative values.

a. Intermediate voltage ratings are placed in the next higher insulation class.
Register to Reply
marcot
Guru
Canada - Member - Specialized in power electronics

Join Date: Feb 2008
Location: Montreal, Canada.
Posts: 1372
Good Answers: 80
#2
In reply to #1

Re: Highpot test on a medium voltage switchgear

06/08/2008 8:23 PM

Thank you very much.

I am surprised by how high is the factory test voltage are. This is almost 4X the rated line voltage. Are these values for impulse test or for the 60 seconds test?

__________________
 Experienced is earned, common sense is taught, both are rare essentials of life.
Register to Reply
ekiechle
Commentator

Join Date: Mar 2008
Location: South Texas - SOMETIMES
Posts: 88
Good Answers: 4
#3
In reply to #2

Re: Highpot test on a medium voltage switchgear

06/09/2008 10:28 AM

Marcot,

I appologize I gave you the wrong table.. please see new table below..

The hi-pot test is a withstand test that shall be performed for one minute. The NETA values represent what shall be used in absence of vendor data, but you will find very little difference with vendor recommendations.

NETA is International Electrical Testing Association, and they have developed standards to assist in acceptance and maintenance testing of electrical equipment. I would recommend purchasing a copy if you do not have one, it will give you good reference specifications for all electrical testing, of which is based on IEEE, & ANSI, standards..

http://www.netaworld.org/

Metal Clad Switchgear

(kV) (rms)

AC

DC

4.761420
8.252737
15.02737
27.045†
38.060†
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
marcot
Guru
Canada - Member - Specialized in power electronics

Join Date: Feb 2008
Location: Montreal, Canada.
Posts: 1372
Good Answers: 80
#4
In reply to #3

Re: Highpot test on a medium voltage switchgear

06/09/2008 1:24 PM

Thank you. I will look into it.

__________________
 Experienced is earned, common sense is taught, both are rare essentials of life.
Register to Reply
Register to Reply
Have a Different Question?
4 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!

Previous in Forum: electrical engineering   Next in Forum: Neo magnets

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Electrical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (49 right now)
Show Members
Advertisement