Distinction between mpcb, mccb, mcb

Bilao

The file was uploaded here in forum by me. Just see the posts published above

Bilao

I splitted the document into two parts.
This is part1
Attachment:002077_EN(1).pdf (109 Downloads)

Bilao

Part2
Attachment:002077_EN(2).pdf (96 Downloads)

maulik

Dear ALL,

I am new to this field and am not quite clear about the exact functional difference between a mcb, mccb, mpcb.

All are for protection and if some document is available that explains the same ???

I have basic idea about each but dont undestand the distinctions.

Thanking you in anticipation.

Maulik

@nkur

Hi There

MCBIn NEMA world, this used to exclusively mean "Main Circuit Breaker", meaning the primary circuit breaker in a group or panelboard / switchboard. In IEC world, it means "Miniature Circuit Breaker", typically a DIN rail mounted circuit breaker in a small format that is limited to 100A, and is intended for use in installations with low fault current capacity (under 25kA) unless protected by upstream fuses. In NEMA world, these devices entered under special rules adopted by UL (UL1077) and are called "Supplementary Circuit Protectors" because they did not meet the criteria already established for "circuit breakers" under UL489. In recent years, many manufacturers have come out with special versions that do now meet the UL489 standards for circuit breakers, so the term MCB has taken on a dual meaning. So in NEMA world, the acronym MCB now has contextual relevance. MCBs / Supplementary Circuit Protectors are sealed units that can be neither maintained or repaired, they are throw-away devices.

MCCBWas originally an IEC term meaning Molded Case Circuit Breaker, but has been very well adopted in NEMA world now, at least at the engineering level. Many rank and file electricians still are not familiar with that acronym because its widespread use in NEMA world is fairly recent. MCCBs generally range from 15A to 1600A, with a few exceptions at either end, and generally start at 14kAIC but go up to 100kAIC for applications with high fault current capacity. There are versions that are Current Limiting (CL) as well. MCCBs are typically sealed units and cannot be serviced, although in larger sizes there are versions with interchangeable parts that can be replaced such as trip units and switch bodies.

MPCBA NEMA world acronym for Motor Circuit Protector, specifically describing a magnetic-only MCCB (no thermal trip elements) that is to be used STRICTLY as part of a factory assembled, listed and tested motor starter assembly. They are often mistakenly specified and used in user-built assemblies, but this is not acceptable in the NEC (US) and CEC (Canada). In IEC world, a Motor Circuit Protector can sometimes mean a completely different device, although generally the MCP acronym is not used to avoid confusion. Devices that incorporate Short Circuit (magnetic instantaneous) trips, adjustable thermal (Overload) trips and a disconnecting means, specifically designed for motor loads, is called a Motor Circuit Protector by some manufacturers, a Motor Protective Switch (MPS) by others, a Motor Starter Protector (MSP) by others etc.

Dear all,

I want to just know that what are the current limiting range for all type of protection. Means if I choose fuse then upto what current I can use that one. and Vice versa for all type  of cb's.