Simple, does the operator want to know which phase (s) were involved in the fault if they have a trip and successful reclose simply by looking at the control or not?
Most likely they do, therefore automatic target reset is turned off.
Thanks a lot dear. Actually truth is I am working as an Intern and started my career not very long ago.This is the first time I am doing recloser settings.Will it be possible for you to go through my protection coordination and let me know if I need to change any settings, If I post all the devices and system details here..?
I suggest getting the Cooper Power Electric Distribution System Protection Manual. It has a good explanation of the requirements for recloser coordination.
As an intern, you should have a more experienced engineer to assist you. If not, your employer should retain an engineering consultant to do the recloser settings and have you work with him to learn the procedures.
If your employer does not agree to one of these approaches, I suggest you start looking for a better employer.
You didn't say specifically what your application was, but since you said "recloser", I assume you are using it in a situation where you have transient faults (i.e.,a utility).
We set ours to reset automatically upon successful reclose. If the device goes to lockout, the targets remain. Otherwise, it has been our experience that when you DO have a lockout condition, your targets will ALL be flagged from last weeks lightning storm and meaningless for the present condition.
Now, if you are talking about when to reset the timing function that takes the device to lockout, I'd like to ask the same question. I've taken the Cooper course (albeit a long time ago) and several others. Maybe I was in the bathroom at the time, but I've never gotten a good explanation on this re-set timing feature and how it should relate to up and downstream devices. We've always set ours at 60 seconds based on the fngineering concept of "we always done it that way".
If this is not the question, then ignore it. I'm not trying to hijack csuf's thread.
I have seen this suggestion a couple of times;
Most distribution faults are caused by birds, small animals, branches or lightning.
The resetting time is set for 2 to 20 seconds to allow a branch or small carcass enough time to fall clear. The recloser then recloses, and if the fault is still present, reopens in a few cycles. This may be repeated one or two times.
The next common cause of distribution faults is failed transformers. The recloser, on the third or fourth reclose will stay on for longer (8, 10 or more cycles) so as to allow (or cause) the primary fuse of a faulted transformer to open. This may be repeated once or twice. If the fault is still present, the recloser will stay open. Total reclosing before lockout, 3 to 5 times.
I have always seen the "closed" timing given in cycles.
respectfully
I think the original question was "target" reset. We've gone to "reclosing relay" reset and on to "reclosing open interval timing". I'll kick off another thread if you're interested?
