What’s the Difference Between MCB, MCCB, and ELCB?
What’s the Difference Between MCB, MCCB, and ELCB? Things You Should Know
When it comes to electrical safety, circuit breakers are your first line of defense. But many people get confused when choosing between MCCB, MCB, and ELCB.
What are they really?
Which one do you need for your home, office, or factory in Singapore?
Let’s break them down in the simplest way possible, no confusing jargon, just what you need to know.
What Are Circuit Breakers?
Before diving into the types, let’s understand what a circuit breaker does.
A circuit breaker is a device that automatically cuts off electricity when there’s too much current or a fault. This helps to protect:
- People from electric shock
- Appliances from damage
- Buildings from fires
There are different types of breakers for different situations. That’s where MCCB, MCB, and ELCB come in.
1. What Is an MCB?
MCB stands for Miniature Circuit Breaker.
It’s the most common type used in homes and small offices. You’ll find them in your DB box (distribution board). Each MCB controls one part of the building, like lights, power points, or air-con circuits.
What It Does:
- Trips (turns off) when there’s too much current
- Protects against short circuits and overloads
Where It’s Used:
- HDB flats
- Condos
- Small retail units
- Office lighting
How Much Can It Handle?
- Up to 100 amps
- Good for low to medium loads
Best For:
Everyday use in homes and light commercial buildings.
Read also Where to Buy Schneider MCB 10A in Singapore? Price List & Supplier Comparison 2025
2. What Is an MCCB?
MCCB stands for Moulded Case Circuit Breaker.
It does the same job as an MCB—but can handle much larger currents. It’s designed for heavy-duty applications and can be adjusted for different current limits.
What It Does:
- Trips on overload or short circuit
- Can be custom-set for higher current ranges
Where It’s Used:
- Industrial buildings
- Factories
- Commercial buildings with large machines
- Data centers
How Much Can It Handle?
- From 100 amps to over 800 amps
Best For:
Large installations or where heavy machines and equipment are used.
3. What Is an ELCB?
ELCB stands for Earth Leakage Circuit Breaker.
It works differently from MCB or MCCB. ELCB doesn’t trip due to high current—it trips when it detects leakage of electricity to the ground, which could be dangerous to people.
Imagine touching a faulty appliance. If current flows through your body to the ground, ELCB cuts off the power to prevent electric shock.
What It Does:
- Detects earth leakage
- Cuts power quickly to prevent harm to people
Where It’s Used:
- Homes
- Wet areas (e.g. bathrooms, kitchens)
- Places with high risk of shock
How Much Can It Handle?
- Usually around 30 mA leakage sensitivity
- Works together with MCBs
Best For:
Protecting people from electric shock, especially in residential areas.
Summary Table: MCCB vs MCB vs ELCB
| Feature | MCB | MCCB | ELCB |
|---|---|---|---|
| Main Use | Basic circuit protection | Heavy-duty circuit protection | Shock protection |
| Trip Condition | Overload / short circuit | Overload / short circuit | Earth leakage |
| Typical Use Area | Homes, offices | Factories, large buildings | Homes, wet zones |
| Current Rating | Up to 100A | 100A to 800A+ | Low current, high sensitivity |
| Adjustability | Fixed | Adjustable | Fixed leakage threshold |
| Protects What? | Equipment | Equipment, systems | People |
Do I Need All Three?
In most cases, you’ll use MCBs and ELCBs together in a residential or commercial setup.
Example in an HDB flat:
- MCBs protect each room’s circuit
- ELCB protects the whole home from electric shock
For factories or large buildings, MCCBs are added to manage higher loads. Sometimes, all three devices are used to provide layered protection.
Common Questions:
Can I replace an MCB with an MCCB?
Not directly. MCCBs are larger, more expensive, and meant for different purposes. You should only use them when required.
Is ELCB the same as RCCB?
They’re similar. RCCB is a newer and more accurate version of ELCB. Many people use the terms interchangeably.
How do I know which one to install?
Always check with a licensed electrician or electrical consultant. Choosing the wrong breaker can be dangerous, or result in unnecessary cost.
Final Thoughts
Understanding the difference between MCB, MCCB, and ELCB doesn’t have to be complicated.
- Use MCBs for regular circuit protection
- Use MCCBs for high-load and industrial settings
- Use ELCBs (or RCCBs) to keep people safe from electric shock
If you’re planning an upgrade, renovation, or new installation in Singapore, talk to your electrical contractor or contact our team at PCP Electric. We’ll help you choose the right protection for your space, your system, and your safety.
