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7 comments
Anonymous Poster

Choose MCCB Sizing and Calculation

09/14/2010 10:13 AM

i have to design a project which is a utility project..

although im not quiet understanding..

how to calculate my mccb rating and size...corrent or not

i have done but i not sure its corrent

i have use p=iv pf for having a load current..with pf=0.85 v=240v n p=3650W

my load current is 17.89A ..SO MCCB that i have to use is 20 MCCB,its that corrent?

cz from what i have seen in standard home is about 40A AND so on..did it relevent to use 20A MCCB..

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Guru
United States - Member - New Member Engineering Fields - Power Engineering - New Member

Join Date: Sep 2006
Location: California, USA, where the Godless live next door to God.
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#1

Re: choose MCCB sizing and calculation

09/14/2010 11:04 AM
  1. This is not Facebook on your smart phone, please use complete words and sentences. Many participants are not native English speakers and may have difficulty trying to translate some of your abbreviationsAs a result you may end up eliminating them from your pool of resources. Even I have trouble with some of them, for example "cz"? Is that supposed to be short for "because"?
  2. By registering and listing your location, we can eliminate the guessing game that results from us not knowing what local codes may apply to the sizing of circuit protection devices. For example if you are in the US, your MCCB must be sized for a minimum of 125% of the FLC of the equipment. If you are not in the US, I cannpot offer meaningful advice, but someone in your country may.
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Guru
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#2

Re: Choose MCCB Sizing and Calculation

09/14/2010 11:54 AM

In addition to what JRaef has said....

1. Since you mention 240V and 'home', you mean MCB.

2. You have a "design project" .. if it is a homework, ok. If it is real life .... please walk away, this is beyond you.

Sorry if i hurt your feelings, but it may save lives.

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Commentator

Join Date: May 2008
Posts: 96
#3

Re: Choose MCCB Sizing and Calculation

09/14/2010 12:25 PM

I personally agree with "kvsridhar", as we basically use the Miniature Circuit Breakers (MCBs) when referring to loads less than 100A(such these CBs are used to control all home' electrical circuits) ...... above 100A we use the Moulded Case Circuit Breakers(MCCBs)........... On the other hand it's up to where you live in order to choose a proper standard (either NEC,IEC,,,,,,,) for electric wiring..............

Thanks..............

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Guru
United States - Member - New Member Engineering Fields - Power Engineering - New Member

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#4
In reply to #3

Re: Choose MCCB Sizing and Calculation

09/14/2010 12:48 PM

"Since you mention 240V and 'home', you mean MCB."

"...we basically use the Miniature Circuit Breakers (MCBs) when referring to loads less than 100A(such these CBs are used to control all home' electrical circuits"

Unless of course he is in the US or Canada or Mexico. Our residential circuit breakers are MCCBs. Hence the reason why I suggested that the OP register and state his/her location. It's pointless to go on like this, differences in product use around the world makes for different semantics as well. It can get very confusing for some people.

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Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

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Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain - possibly to become "South Scotland" or "Non-Caledonia" from September 2016. Kettle's on.
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#5

Re: Choose MCCB Sizing and Calculation

09/15/2010 4:20 AM

→ British Standard 7671 again.

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Guru

Join Date: Jun 2010
Location: srilanka
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#6

Re: Choose MCCB Sizing and Calculation

10/03/2010 1:49 AM

Refer manufacturer's cataloque(Hager or any other)

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pnaban
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Anonymous Poster
#7

Re: Choose MCCB Sizing and Calculation

10/27/2010 3:32 PM

you can you use (MCB) UP TO 100 A BUT above 100 and up to 1000 A you must use a (MCCB)

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Users who posted comments:

Ali18 (1); Anonymous Poster (1); JRaef (2); kvsridhar (1); pnaban (1); PWSlack (1)

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