When comparing an MCCB vs. RCCB as protection devices, a lot can be said to be different – because, whereas an MCCB provides overload and short-circuit protection, an RCCB offers high-sensitivity ground fault protection. In other words, an RCCB is more of a residual current regulating device. Continue below for more about MCCB and RCCB breakers and their differences.
MCCB RCCB Meaning
For a better understanding of the MCCB and RCCB difference, let’s look at the meaning behind them. After the MCCB RCCB meaning, we’ll then compare the differences between them.
What is MCCB?
MCCB stands for Molded Case Circuit Breaker. It’s essentially a type of circuit breaker that provides both thermal and magnetic protection against overloads and short circuits in electrical circuits. This device is typically used in AC mains or DC supplied applications, where it offers circuit and equipment protection.
What is RCCB?
RCCB stands for Residual Current Circuit Breaker. It’s a type of device that offers high-sensitivity overcurrent protection in electrical circuits. An RCCB is used to protect people from electrical shock other potential hazards caused by earth leakage currents.
Now that we’ve seen the meaning of MCCB and RCCB, let us look at their differences.
MCCB Vs. RCCB
The MCCB RCCB difference can be noted in the following major ways: working and construction, ratings, tripping actions, protection methods, number of poles, and presence or absence of a test function
MCCB Vs. RCCB: Construction and Working
Starting with MCCB vs. RCCB in terms of construction, we can say that MCCBs are more detailed in design as compared to RCCBs. An MCCB construction consists of bimetallic elements, a magnetic trip element, contacts, and an arc chute for arc extinguishing.
On the other hand, an RCCB is simpler and comprises a current transformer, magnetic mechanism, and contacts or terminals. The MCCB thermal magnetic mechanism uses this working principle:
- When an overload occurs, a bimetallic strip expands, bends, and separates contacts to trip the affected circuit. This causes the current flow to stop. Similarly, when a particularly high current short circuit, the MCCB magnetic unit provides instant tripping action.
- An RCCB on the other hand, works on the basis of earth fault current sensing. When there is an imbalance in the line-to-neutral current, it energizes to trip the affected circuit, thus providing ground fault protection..
MCCB Vs. RCCB: Ratings
The MCCB RCCB difference is also seen I the different ratings. An MCCB will have a higher current rating of up to several thousand amperes. Compare this with that of an RCCB, which is normally up to 160A.
The higher MCCB ratings the device can withstand fault currents that carry high currents, such as short-circuits In contrast, high current short circuits may end up destroying the device. This means the RCCB is not to be used on its own, but rather in conjunction with MCCB or other suitable breaker to ensure circuit safety.
MCCB Vs. RCCB: Tripping Action
The MCCB tripping action is thermal magnetic, which means it uses the bimetallic strip and magnetic trip element to trip the circuit due to an overload or short circuit. An RCCB trips when a current imbalance is detected between line and neutral.
As you can see, the two devices trip differently, and are used in different applications. For example, while the function of MCCB breakers is used to protect circuits and equipment from overloads and short circuits, an RCCB is mainly used to provide protection against earth faults and shocks.
MCCB Vs. RCCB: Protection
Speaking of RCCB and MCCB protection, we can see that the protection method of the two devices vary significantly. An MCCB works on a thermal magnetic mechanism, which means it’s built to protect against both overload and short circuit faults.
An RCCB only offers protection against residual currents or earth leakage current, and is usually used to prevent shocks from electricity and other hazards caused by earth fault currents. It should be noted that RCCBS do not protect against short circuits.
For complete protection set-up, therefore, it becomes important to use both devices in the same distribution system, as mentioned earlier. However, some MCCB types today also come with RCCB protection, which can save you the hassle of having to install two separate devices.
MCCB Vs. RCCB: Number of Poles
The number of poles on a device refers to the number of contacts present in it, and this is an important factor one should consider when selecting the right protection device for an application.
An MCCB can be different configurations when it comes to the number of pole configurations, from 1 and 2-pole MCCB for single phase systems to 3-pole to 4-pole MCCB for 3-phase circuits. An RCCB usually only comes in two configurations: 2 and 4 poles.
MCCB Vs. RCCB: Test Function
In order to ensure that the protection devices are functioning properly, a test button or other test feature may be provided. The RCCB comes with one. The MCCB doesn’t and can only be tested by use of a testing device.
But this MCCB RCCB difference is mainly because of the fact that an RCCB provides protection against earth faults, and a test button is important to ensure that the device is working correctly.
An MCCB provides protection against overload and short-circuit faults, which can be tested by using a testing device like an insulation tester or multimeter.
When comparing an MCCB vs. an RCCB, it is important to consider the different ratings and features that each device offers. An MCCB can be used for protection against overload and short-circuit faults, while an RCCB is mainly used to provide protection against earth faults.
We hope this article has given you a good understanding of the differences between an MCCB and RCCB. Remember, both these devices provide important protection to your electrical system, with each offering own distinct advantages and features.
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