Replacement of Fuse With MCCB

[zaza123]

I need to replace Fuses in Control Circuit with the MCCB. The rating of Fuses are 2A 4A, 10 A.
The need to replace these fuses came as it is difficult to trouble shoot the System & change the fuse every now & then.
My question is that the Equivalent MCCB atings shall be same or diferent.

 

[hameedekhlas]

It is better to calculate per NEC in consideration with connected load and existing cable size.

 

[rbulsara]

zaza:
Yes. Look for miniature circuit breakers.

Rafiq Bulsara

http://www.srengineersct.com

 

[ScottyUK]

If this is in an MCC with a high fault level then be careful about breaking capacities: MCBs are good for maybe 10kA, but a control fuse is usually good for 80kA or more. Make sure you have a type-tested combination before relying on an MCB with an upstream device backing it up.


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If we learn from our mistakes I'm getting a great education!

 

[IndianTechEngg1001]

I agree with ScottyUK. If SC ratings are met you can very well use MCB in place of fuses. This is now a days everywhere used in control circuits. It can solve your purpose.

If short circuit level is more than 10kA then MCCB will be an option. You will also have to see the space availabilities in your panel as MCCDs are little bigger in sizes.

 

[zaza123]

Dears
Thanks for your reply,
I will check the Fault level of the 480 V system.
As per my understanding(Please confirm) you are recommending if the Fault level is below 10 KA use MCB, if more than 10KA use MCCB.
I also think that the Space will not be constraint as for Phase & Neutral there are Seperate fuses, but using 2 pole MCB or MCCB the space occupied will be same.

 

[IndianTechEngg1001]

Yes Isc upto 10KA use MCB and for Isc >10KA use MCCB. You can also consult different manufacturer catalogs to know these ratings before you decide.