×
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

Surge Arfrestors for MV

Surge Arfrestors for MV

Surge Arfrestors for MV

(OP)
Dear All.
Could you please attached some link with good theoretical explanation about surge arrestors.

Shortly.
Surge arrestor for 6kV , oxid type, max operating voltage 7.5kV. 6kV ungrounded system. Ground fault on the outgoing
involved to two-phase fault, operated line protection and infeed protection too,  becouse some problem, operated auto transfer and closed coupler, operated recloser on the line.
Same pict, again trip on the coupler and line. After 3min infeed closed remotly and system back to operation.
All protection are EM relays. Team checked all relays and CB's , all fine. Second fault in this system, same fault in another SS, all problem started after installation of new type of SA.
Some stuipid idea. SA operated due the overvoltage ( ungrounded system) and current is enough for the protection operation. But from other hand is unpossible, 3000A for the 2sec!!!! and SA back to operation w/o damages, for my pinion it was burnt.
Any ideas
Thanks in advance.
Best Regards.
Slava

RE: Surge Arfrestors for MV

I have a query. In a steel plant, there are 50 MVA 220/33 kv and 220/11 kV transformers. LV  side  of transformer is connected with XLPE cable through an air fiiled cable box.Client is asking me to provide Surge arresters inside cable box.ie 12 & 33Kv arresters.
1) Does an  arrester really require at this location.Cable system is not exposed one and there is no chance of any external surges coming on the cable system.Surges transferred from primary of transformer will be attenuated by the cable capacitance so that there seems no need for a arrester.What  is the industry practice?

2)In case arrester is required, why and how to select the arrester rating?

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