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Join Date: Dec 2009
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# MCC Panel Current Carrying Capacity

12/07/2009 1:57 AM

dear all,

i need to calculate a current carrying capacity of incoming MCCB for a MCC panel

as per IEC standard

datails:

we have 10 branch circuits of each capacity 25kw

voltage:3ph,415v

can any one suggest me regarding this and IEC stardard code

rkram

Pathfinder Tags: MCC circuit breaker
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#1

### Re: MCC Panel Current Carrying Capacity

12/07/2009 3:32 AM

There is an existing thread running on this topic.

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#2

### Re: MCC Panel Current Carrying Capacity

12/08/2009 3:52 AM

refer IEC 61439 and if it is not clear then do come back to the thread

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#3

### Re: MCC Panel Current Carrying Capacity

12/08/2009 10:18 PM

can you tell the IEC standard formula for the calculation of Incoming rating of MCC panel

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#4

### Re: MCC Panel Current Carrying Capacity

12/08/2009 10:25 PM

dear sir,

i am using the following formulae to calculate the Incoming rating of MCC panel

NOT Less than Incomer current rating = 25% of full load current of largest motor + Full load current of remaining motors

and

NOT More than Incomer current rating = 250% of full load current of largest motor + Full load current of remaining motors

I have selected inbetween the above ratings.

Please tell me am'i following the IEC standard

can you give the IEC standards document related to this MCC rating calculation

Thanks,

with best regards,

rkram

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#6

### Re: MCC Panel Current Carrying Capacity

10/11/2021 4:25 AM

Invitation declined.

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#7

### Re: MCC Panel Current Carrying Capacity

10/11/2021 4:32 AM

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#5

### Re: MCC Panel Current Carrying Capacity

12/09/2009 2:54 PM

If u ask me,i would simply help u to calculate yr MCCB incoming current rating.

Yr total load is 250kw(assume full load).P=root3VIcosO,O is phi.I=P/root3VcosO=250000/1.732x415x0.8=250000/575.024=434.76Amps. Multiplying 434.76 by a factor based on regulation(check yr Regulations on protective devices calculation),you will get 782.57Amps,then select MCCB range of 800Amps.

This will carry and protect yr total loads conveniently if u get a quality ABB/MITSUBISHI or other quality breakers.

Patrick Whowha

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