wroggent
Electrical
- Aug 20, 2012
- 288
I have no interest in implementing series rated systems but I'm wanting to know some more information about it.
1.) How can you obtain a series rating per NEC 240.86(B)? I understand that the OCPDs must have been tested together by a NRTL - the meaning of this isn't entirely clear though. Can I simply choose two OCPDs from a manufacturer's data sheet that shows the two devices having been tested together? Or, must I purchase the devices from the data sheet and then send it to the NRTL to be tested? I can't find any documentation that explains how the system needs to have been tested. Is it OK to test identical devices and assume the one's I have will perform exactly the same? Or, does a combination need to be tested every single time? And do I need to send them the enclosure, etc., as well? Isn't a series rating unique to the installation and not entirely dependent on the OCPDs (think bus bar bracing)? If it must be tested every time, is paragraph 3 of "Application Considerations for Series Combination Overcurrent Protective Devices (OCPD) in New Installations" wrong?
2.)This is somewhat of a restatement of question 1. If I have any existing installation where I need a series rating, if I were to install OCPDs approved for a series rating from a manufacturer's data sheet, would this be a series rating per 240.86(A) or 240.86(B)? If it's 240.86(B), couldn't it also be 240.86(A) under certain circumstances? - You'd just need to choose a combination that meets the passivity requirement of 240.86(A) and provide some bogus calculation that says the combination will work.
3.)Is the required labeling different for 240.86(A) and 240.86(B)?
4.)Does 240.86(A) being for only existing installations preclude 240.86(B) from being applied to existing installations?
5.)Can you provide a definition of existing and new installations? How they're different? How they're similar? E.g., moving equipment around - new or existing installation? Adding a breaker in a panel - new or existing?
Thanks for your input.
1.) How can you obtain a series rating per NEC 240.86(B)? I understand that the OCPDs must have been tested together by a NRTL - the meaning of this isn't entirely clear though. Can I simply choose two OCPDs from a manufacturer's data sheet that shows the two devices having been tested together? Or, must I purchase the devices from the data sheet and then send it to the NRTL to be tested? I can't find any documentation that explains how the system needs to have been tested. Is it OK to test identical devices and assume the one's I have will perform exactly the same? Or, does a combination need to be tested every single time? And do I need to send them the enclosure, etc., as well? Isn't a series rating unique to the installation and not entirely dependent on the OCPDs (think bus bar bracing)? If it must be tested every time, is paragraph 3 of "Application Considerations for Series Combination Overcurrent Protective Devices (OCPD) in New Installations" wrong?
2.)This is somewhat of a restatement of question 1. If I have any existing installation where I need a series rating, if I were to install OCPDs approved for a series rating from a manufacturer's data sheet, would this be a series rating per 240.86(A) or 240.86(B)? If it's 240.86(B), couldn't it also be 240.86(A) under certain circumstances? - You'd just need to choose a combination that meets the passivity requirement of 240.86(A) and provide some bogus calculation that says the combination will work.
3.)Is the required labeling different for 240.86(A) and 240.86(B)?
4.)Does 240.86(A) being for only existing installations preclude 240.86(B) from being applied to existing installations?
5.)Can you provide a definition of existing and new installations? How they're different? How they're similar? E.g., moving equipment around - new or existing installation? Adding a breaker in a panel - new or existing?
Thanks for your input.