MCB vs. RCCB vs. RCBO: Complete Guide to Breaker Types
In your distribution panel you'll find different types of breakers — each type has a specific function that the others don't perform. Understanding the difference helps you assess your home's protection level and what's missing.
Quick Answer
MCB protects from overload, RCCB from leakage, RCBO does both. Which does your apartment need — and how to spot counterfeit breakers flooding Egyptian markets.
Complete Comparison of Breaker Types
Thermal breaker (MCB — Miniature Circuit Breaker): Protects the circuit from overload and short circuit. It's the foundation of every panel. Trips when current exceeds its rated value (10–63A). Does NOT protect against leakage current or electric shock.
Leakage breaker (RCCB — Residual Current Circuit Breaker): Protects people from electric shock by measuring the current difference between the live wire and neutral. If more than 30mA leaks — it trips in 30 milliseconds. Does not protect against overload alone — used with an MCB.
Combined breaker (RCBO — Residual Current Breaker with Overcurrent): Combines MCB + RCCB functions in one breaker. Protects against overload, short circuit, and leakage simultaneously. The best option for critical areas (bathroom, kitchen) and modern smart panels. More expensive but highest protection.
Main switch (Main Switch / MCCB): Large breaker at the start of the panel that cuts all electricity. Doesn't provide circuit-specific protection — used for total disconnection during maintenance or emergencies.
Surge Protection Device (SPD): Not strictly a breaker but installed alongside breakers in the panel. Protects appliances from sudden electrical surges (lightning, power cut and return). Essential in areas with frequent power outages.
Quick Comparison Table
| Type | Overload | Short | Leakage |
|---|---|---|---|
| MCB | ✅ | ✅ | ❌ |
| RCCB | ❌ | ❌ | ✅ |
| RCBO | ✅ | ✅ | ✅ |
FAQ
Is having only MCBs in the distribution panel sufficient?
No. An MCB alone protects wires from burning but doesn't protect people from electric shock. The Egyptian code requires an RCCB or RCBO especially for wet areas. Without an RCCB your home is not fully protected.
What RCCB sensitivity is appropriate for a home?
For electric shock protection: 30mA is the standard recommended sensitivity. Higher values (100–300mA) protect against fire only. For homes with children: some experts recommend 10mA as a higher sensitivity.
Does RCBO replace both MCB + RCCB?
Yes completely — that's its purpose. One RCBO per circuit = highest protection and clearest isolation. Its only drawback: higher cost. In modern professional panels: RCBO on every circuit is far better than a shared RCCB.
How do I know if the RCCB in my panel is working?
Press the small Test button on the breaker. If it trips immediately = it works. If it doesn't trip = the breaker is faulty and must be replaced immediately. This test should be performed monthly.
What is the approximate cost of upgrading a distribution panel to RCBO per circuit?
RCBO units range from EGP 150–400 each depending on specifications and brand. A medium apartment needs 6–10 circuits = total cost for a full RCBO panel: EGP 3,000–8,000 installed.