What are the requirements/guidelines for coordination studies?
What are the requirements/guidelines for coordination studies?
(OP)
Is there a requirement or guidline for performing a new coordination study/short circuit analysis when a facility's existing electrical system has had changes and additions made to it? While I assume it is best practice to do this, is there a section of the NEC, NFPA, or IEEE standard that specifically references this requirement? Thank you.






RE: What are the requirements/guidelines for coordination studies?
It is important to note that codes like NEC are only concerned with safety and not with minimizing production or monetary losses or inconvenience to the owner. For example, the code is happy as long as a breaker trips and clears a fault, whether that breaker be the building main or a branch breaker.
It is up to the end user to decide (and people advising them) as to what is in their best interest. If they want to limit the outage to faulted area only, they should have a coordinated system, as best as possible.
Code also does not prescribe exact procedures, but there are recognized procedures in standards like IEEE (Red Book)and IEC standard 60909.
Coordination study goes in hand in had with short circuit study and NEC 110.9 and 110.10 requires that. Also there is a good article in the latest EC&M magazine, on the SCCR subject and NEC.
Rafiq Bulsara
http://www.srengineersct.com
RE: What are the requirements/guidelines for coordination studies?
RE: What are the requirements/guidelines for coordination studies?
The exception is for branch system off a single transformer 125 kVA and 240Vac or less.
RE: What are the requirements/guidelines for coordination studies?
It is in the February 2010 EC&M issue, "The SCCR Liability Trap" article.
Rafiq Bulsara
http://www.srengineersct.com
RE: What are the requirements/guidelines for coordination studies?
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: What are the requirements/guidelines for coordination studies?