Hi
I have gone through the article below and I am not sure if I have it wrong or article has the other way round.
http://www.idc-online.com/technical_references/pdfs/electrical_engineering/current_transformer_concepts.pdf
On Page 2 of pdf, It says in low excitation, Im > Ib and other two...
Hello All,
I asked a consultant to do a arc flash study on a 1600 A 120/208 switchboard. Unit has molded case circuit breakers with
Schneider Micrologic 6.0 P trip unit. i need some input in testing these breakers for commissioning using primary injection.
I will not be testing it myself but...
Hello All,
My application involves a 5 MVA 27.6 kv/4.16 kV Primary Delta and Secondary is star solidly grounded transformer. A 4.16 kV switchgear is fed from the secondary and I have been told by my utility standard guys that the practice of connecting outgoing feeder cables is as following...
I have been working on basic feeder protection for a while now and recently started focusing on concepts of directional over-current protection and distance protection.
It seems like I am missing some conceptual background to get a handle on these topics. Here is what I would like to start...
Hi,
This might be more of a controls related question. I have attached a pictures which has two schematic.
1. Existing Schematic
2. Planned Schematic
My Distribution utility shares substation with the transmission utility. Bus protection and bus is owned by transmission utility but our...
Please see the link below;
Hi Your opinion would be appreciated:
http://www2.selinc.com/techpprs/6061.pdf
I have read this paper few times and this line on page 5 puzzles me:
"If the nondirectional ground overcurrent protection for Relay 1 is lowset,
this protection could operate...
Hi all
My application is an installation in a substation. I bought a 120/208 v station service switchboard. I hired a consulting firm to do arc flash energy on the switchboard.
Switchboard is fed from a 750 kva 13.8kv/208v transformer. It has two cells. Right section has a main-tie-main...
Hi
I have a ABB R-Mag 27 kV Outdoor breaker. Relay is SEL 451. I have been told by ABB that tripping current for the breaker ED2 motherboard is 20 mili Amps.
Relay is 120 ft away from the breaker wired through a 125 VDC 10C #10 AWG conductor.
I am using standard output contacts, which the...
Hello,
I came across this document published by CEATI international, Distribution Overcurrent Protection.
I went through the whole 240 page document and found some interesting information about coordination between fuses, reclosers and station breakers. One of interesting arguments was to...
HI,
I AM ASKING THIS QUESTIONS, WHEN I HAVE EXHUASTED ALL AVENUES FOR AN EXPERT AND SATISFACTORY OPINION IN MY NEIGHBOURHOOD.
I WOULD SINCERELY APPRECIATE YOUR OPINION.
Background:
Project involves replacing an old outdoor GE Oil type 13.8 kV breaker. Field wiring would remain intact and...
