Selective Coordination

[Nate Scott]

Are selective coordination requirements of elevator, emergency and legally required systems per NEC 620.62, 700.27 and 701.18 being enforced in other parts of the country because I was told it is not.

 

[raider1]

It is enforced in my area. (North Logan, Utah)

Chris

 

[iwire]

Are selective coordination requirements of elevator, emergency and legally required systems per NEC 620.62, 700.27 and 701.18 being enforced in other parts of the country because I was told it is not.

Enforced or Adopted?

If an area did not adopt those sections or made amendments to them that is one thing.

If an area simply does not enforce an adopted rule and the designer / installer decides not to follow the adopted rule due to lack of enforcement that designer / installer will forever be 'on the hook' for that violation.

 

[RB1]

I have heard that some jurisdictions are negating the first .10 second for coordination of molded case circuit breakers. Does anybody know if there is any truth to this?

 

[ron]

Adopted in many areas but not enforced in some cases because the AHJ is not familiar with the requriements.

 

[jim dungar]

I have heard that some jurisdictions are negating the first .10 second for coordination of molded case circuit breakers. Does anybody know if there is any truth to this?

Wisconsin has been enforcing the 2005 NEC as written. If the legislature approves the proposed amendment, when Wisconsin adopts the 2008 NEC there will be a state exception for times of 0.1 sec or longer.

 

[steve66]

I have heard that some jurisdictions are negating the first .10 second for coordination of molded case circuit breakers. Does anybody know if there is any truth to this?

And I've heard that others are negating the first 0.01 seconds.

It's really hard to coordinate circuit breakers below that level. I guess they want us to go back to using fuses everywhere.

IMO, this is one of those code sections that sounds great on paper, but just isn't practacle in the real world.

Steve

 

[jim dungar]

I guess they want us to go back to using fuses everywhere.

Fuse "ratio charts" are only good for that specific manufacturer, as soon as you put in a different brand fuse (which of course never happens:smile: ) you loose your guarantee of coordination.

 

[ron]

Steve,
Since the proposal was introduced and lobbied for by a fuse manufacturer, you may have hit the nail on the head!