Arc Flash
Arc Flash
(OP)
Can anybody Explain instantaneous Overcurrent relay functionality and how does it will help in reducing the incident
Energy.
Energy.
When was the last time you drove down the highway without seeing a commercial truck hauling goods?
Download nowINTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS Come Join Us!Are you an
Engineering professional? Join Eng-Tips Forums!
*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail. Posting GuidelinesJobs |
|
RE: Arc Flash
An instantaneous overcurrent element will trip the upstream breaker with no intentional time delay whenever the current increases above its setpoint. Compared with a time overcurrent element, the instantaneous element will operate much faster, reducing the arc time and lowering the incident energy.
However, use of instantaneous elements can seriously compromise coordination with downstream protection, so there is generally a tradeoff required. Use of a "maintenance switch" can be used to activate the instantaneous trip only when maintenance work is being done on the equipment.
RE: Arc Flash
Operate the breaker faster= less energy.
It sounds like you are making this harder than it should be.
RE: Arc Flash
But you cannot leave it that way permanently or you run the risk of a system shutdown from nuisance tripping. What some people do is provide a laser scanner in front of the switchgear that automatically enables the Maintenance Mode when someone enters the Limited Approach Boundary so that when they walk away, they don't forget to turn the Maint. Mode off.
"Dear future generations: Please accept our apologies. We were rolling drunk on petroleum."
— Kilgore Trout (via Kurt Vonnegut)
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: Arc Flash
RE: Arc Flash
Instantaneous protection is mainly used by protection engineers in order to avoid unnecessary thermal stress to healthy equipment and helps in restricting the spreading of damage in the faulty node.
G.F.
www.engineering-services.gr
RE: Arc Flash
Yes, that may be true, but the original question was regarding instantaneous overcurrent protection.
RE: Arc Flash
RE: Arc Flash
http://ww