×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

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!

*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

How to check cracks on ESP ceramic isolator?

How to check cracks on ESP ceramic isolator?

How to check cracks on ESP ceramic isolator?

(OP)
Hi

Is there a method/product we can use to check for cracks on ESP ceramic isolators?
Can we use the dye employed for cracks on metals?

RE: How to check cracks on ESP ceramic isolator?

Seems like it would work - https://www.youtube.com/watch?v=xEK-c1pkTUI

The dye is non reactive and operates independently of being a metallic part.

A method that won't work is magenetic particle inspection as it depends on the ability of metal to concentrate the magnetic field at discontinuities and ceramics are usually non-magnetic.

RE: How to check cracks on ESP ceramic isolator?

Wouldn't the dye tend to form arc tracks if it can't be completely cleaned off?

RE: How to check cracks on ESP ceramic isolator?

You would need to use a dye with very high dielectric properties.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: How to check cracks on ESP ceramic isolator?

Ultrasonic methods would probably work, as long as the crack was not at some specific hard-to-reach angles within the structure.

Converting energy to motion for more than half a century

RE: How to check cracks on ESP ceramic isolator?

A Doble (or similar) Power Factor / Tan Delta "Hot Collar" test has been used for decades to find cracked or broken insulators. If you don't have a test set, there are plenty of service companies that will.

From a NETA article on testing:

"Hot Collar Test
A hot collar test generates a localized high-voltage stress by using and energizing a conductive collar around the porcelain. This can determine dielectric losses (watts and current, as PF is not analyzed) through various sections of any bushing when troubleshooting high PF results. It is useful to detect cracked porcelain, deteriorated cement joints, gasket leaks, or faults within condenser layers in condenser-type bushings, as well as to check the oil level of oil-filled bushings when normal oil level readings have been established or when comparing to bushings of the same type. If an abnormal mA or watts reading is obtained when the test is performed under the top petticoat, the test should be repeated under the second petticoat and move further down until normal readings are found.

The hot collar test can be performed with any of the test modes — GST, GST-g, UST — using one or multiple collars depending on the anticipated outcome of the troubleshooting (Figure 7 from Paul Gill’s Electrical Power Equipment Maintenance and Testing).

Guidelines for evaluating hot collar data:

• Watts loss

– <100 mW: Acceptable

– ≥100 mW: Unacceptable, possible contamination

• Current

– Within 10% of similar bushings: Acceptable

– <10% of similar bushings: Unacceptable, low level of liquid or compound, possible faults within condenser layers
"

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! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close