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Posted By: Niko Series breakers - 08/11/07 06:49 PM
The city electric plan checker needs the following on the plans: DOCUMENTATION REGARDING SERIES BREAKERS :

This was the list that was given to me by the building owner i was not available to ask the plan checker what he meant by series breaker documentation

Can you guys tell me what he means?

Thank you.
Posted By: jraef Re: Series breakers - 08/12/07 01:05 AM
When you have one breaker used upstream of others, they all must be listed (by UL) for use in series, i.e. the let-through of the upstream breaker is lower than the withstand of the downstream ones. If they are in a panelboard and all are the same make, you should be able to get that info from the manufacturer now. If you have mixed brands within a panelboard or are using stand-alone breakers, you may have to pay a PE to do a certified coordination study on them.
Posted By: renosteinke Re: Series breakers - 08/12/07 02:26 AM
I'm not sure I understand that explanation.

"Selective co-ordination" is one thing.

I really can't accept the implied requirement that every panel and disconnect be of the same make as the main switchgear.

I think we still need a better explanation of 'series rating,' and when it is relevant.
Posted By: gfretwell Re: Series breakers - 08/12/07 03:58 AM
This might be helpful. Poke around the search box for a few more articles from the magazine
Posted By: resqcapt19 Re: Series breakers - 08/12/07 03:58 AM
Series rating applies when you are installing a downsteam breaker that has a lower interrupting rating than the available fault current at that point on the circuit. It is the only way you can make that type of installation.
Quote
I really can't accept the implied requirement that every panel and disconnect be of the same make as the main switchgear.

In general a series rating is only obtained by testing. Manufacturer A does not have their breakers tested in combination with other brands. This restriction only applies when you are using a series rating.
Don
Posted By: renosteinke Re: Series breakers - 08/12/07 04:03 AM
Thank you, Don, for straightening out an issue that is confused enough ...
Posted By: Scott35 Re: Series breakers - 08/12/07 07:06 AM
Niko:

Quote

The city electric plan checker needs the following on the plans:
: DOCUMENTATION REGARDING SERIES BREAKERS :

Can you guys tell me what he means?


What the Plans Examiner is requesting here is for Manufacturer's Spec documents, to be submitted to the Plan Check firm (in hard copy, or "printed" format), which are relavent to a Series Rated System.

These documents will list devices and equipment, that are acceptable to be installed within a Series Rated System. Manufacturer's part numbers + categories will be referenced, as to their use downstream of a given Service Section or Gear Section & OCPD.

If your System IS NOT Series Rated, then write in your reply to the Correction notice:
"This Electrical System Is Fully Rated, Not Series Rated", then submit the marked up correction list to the P/C firm (P/C = Plan Check).
Submit it, along with your contact information + note to have the P/C person contact you for further questions.

If the System is / will be Series Rated, then go to the Manufacturer's website, and printout / download "Cut-Sheets" for their approved combinations of equipment and devices usable on Series Rated Systems.

If you are unsure if the System is / is not Series Rated:
  1. Review the 1 Line Diagram + spec notes of the Planset, look for some indication of Series Rating,
    or,
  2. Verify the On-Site conditions - need to know the Fault Levels at Panelboards, Disconnects, Gear Sections and the Service Equipment.


Maybe there is a high fault level indicated at a remote Panelboard ( > 10KAIC ), which drew attention to the P/C during the exam - and this is why they request the documents.

If this project is Design / Build, and you are the designer, you _should_ know if the System is / will be Series Rated.

I include notes on the cover page, the 1 Line page, and the Panel Schedule page(s) which call out if a System is or is not Series Rated - as follows:

* This System Is a _FULLY RATED_ System (NOT Series Rated).
SCA levels at various points along the system do not exceed the AIR (AIC) of installed Overcurrent Devices or Panels.

or;

* This System Is _SERIES RATED_.
Supporting documents are attached to this Planset, and will be submitted as separate documents - in addition to this Planset - for Plan Examination.
Overcurrent Devices, Panelboards, Service Equipment and other related Equipment intended for use in a Series Rated fashion, have been listed in the Materials Specifications list of this Planset, and have been identified at points on the 1 Line Diagram(s).

Scott
Posted By: Niko Re: Series breakers - 08/13/07 02:30 PM
Thank you gentelman for the detailed explanation.
I learned something today.
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