mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Does anyone know how I can obtain the trip curves to Murray residential loaded center molded case breakers?
Murray trip curves
- Thread starter mbrooke
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If they have been listed as UL489 then they must comply with those parameters.
Since the posibility of field testing is slim to none having trip curves iis of little use. If your intent is coordination residential breakers really don't have that capability.
If you happen to obtain a set of trip curves then what?
NEMA AB4 provides guidance for field testing breakers regardless of the manufacturer.without an extremely expensive factory testing capability verifying breaker calibration beyong the procedure as included in NEMA AB4 is not possible.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
You can get trip curves for Siemens QP,BQ, BL breakers, they are the same.
http://w3.usa.siemens.com/powerdistribution/us/en/resources/Pages/DownloadCenter.aspx
As to the point that I was trying to get across should you get a copy of the trip curves(s) then what? You can't test the breaker for factory caslibration nore are you able to use them for coordination. May there be much to do about nothing or may it be just curriosity?
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I agree, I was just responding to his request. The only reason I know that is because when I worked at Siemens, I would get this request over and over. I would initially make that point you made, but most of the time the request was coming from a contractor who had no choice but to to supply it to a consultant, and it was just easier to give them the darned TCC than to try to educate them as to the pointless nature of the request. I also had to write "official" letters attesting to the fact that the Siemens and Murray breakers were exactly the same, because the consultant was a rubber stamper, who could not rubber stamp it without a direct reference on company letterhead stating that fact. In fact when I was there, the TCC didn't say it applied to the QP (plug-in) breakers, only the BL bolt-ins, so I had to write a letter on that too.
It is so nice to know somebody else who was in the same boat as I was. I worked a (w) for 13 years and Eaton/C-H for 5 more. Some of my replies may show my frustration as often times I am not told the rest of the story such as why the question is being asked in the first place and what they are trying to do. All to often I have been asked questions in such a way in order to get and answer that they want to hear and not being told the entire story.
There are certain questions that I have become aware of over the years that causes me to question if the person who is asking the question is familiar with safe electrical practices and procedures and their qualifications which is important to know since a misunderstanding could be catastrophic.
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