Author Topic: Are MNEAC30QZD Type Breakers Rated For Switch Duty?  (Read 171 times)

Vic

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Are MNEAC30QZD Type Breakers Rated For Switch Duty?
« on: November 07, 2022, 04:46:20 PM »
The above 277 VAC breakers are rated as Supplementary Protection,  and the description says something like, these breakers are tested ONCE  (a single event, to me).  This implies to me, that trying to use one as a disconnect, might be ill advised.

Was looking for a Branch Rated AC breaker, in the 30 - 40 Amp range, Two Pole and single pole  ...

TIA,  Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

boB

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Re: Are MNEAC30QZD Type Breakers Rated For Switch Duty?
« Reply #1 on: November 07, 2022, 07:04:10 PM »

I wouldn't worry about that.  I've switched one of those breakers at least 3 times and it still worked.

Seriously, I don't think there is an issue at all.  And I bet that the UL test makes them switch MANY MANY times and still has to work.

But I don't remember how many times that would be.  I seem to remember the DC breakers needing to be switched MANY times when we were re-rating from 125 VDC to 150 VDC.

The insides of those are the same as I remember.

If I am wrong, someone will hopefully correct me but I sure don't remember anything about number of times switched.

boB
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Vic

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Re: Are MNEAC30QZD Type Breakers Rated For Switch Duty?
« Reply #2 on: November 07, 2022, 11:38:05 PM »
Hi boB,  thanks for the reply.

From discussions here,  IIRC, that MN breakers have been tested for thousands of cycles at rated voltage and current (5,000 times, comes to mind).  Think that this was part of the ETL listing (recognition, or whatever).

The 3,000 AIC rating of these Supplemental-rated breakers should be plenty,  forgot just where i saw the reference, implying that this category of breaker migh not be tested for many, many cycles under some load.

The MNEAC 120 VAC breakers have the 5K AIC rating, required for Branch Circuit breakers.

I will go ahead with this application and the Supplemental-rated MNEAC breakers, after doing some more study  ... 

Thanks again, take care, 73,  Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!