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RCD vs RCCB: Key Differences, Protection Limits & Which to Choose
RCD vs RCCB explained: compare RCCB and RCBO protection limits, RCD types, sensitivity and ratings, then use the selection tool to choose the right device.
RCD vs RCCB in one sentence: RCD is the general name for residual-current protection devices. An RCCB is one type of RCD that detects earth leakage but does not provide overload or short-circuit protection.
If you are comparing RCD vs RCCB, they are not two equal product categories. RCCBs and RCBOs both belong to the RCD family. If you need residual-current, overload and short-circuit protection in one device, the correct comparison is usually RCCB vs RCBO.
RCD vs RCCB: Quick Comparison
| Feature | RCD | RCCB | RCBO |
|---|---|---|---|
| Meaning | Umbrella term | A type of RCD | A type of RCD |
| Earth-leakage protection | Depends on device | Yes | Yes |
| Overload protection | Depends on device | No | Yes |
| Short-circuit protection | Depends on device | No | Yes |
| Typical standard | Family term | IEC/EN 61008-1 | IEC/EN 61009-1 |
| Typical installation | General category | With a separate MCB or fuse | Individual circuit protection |
RCD / RCCB / RCBO Selection Tool
Answer the questions below for a practical starting recommendation.
General guidance only. Final selection must follow equipment instructions and local wiring rules and be verified by a qualified electrician.
What Is an RCD?
RCD stands for residual current device. It monitors the current flowing through the live conductors and disconnects the circuit when an imbalance indicates that current may be leaking to earth. RCD is a category name, not one single construction. RCCBs, RCBOs and some socket or portable protection devices can all be RCDs.
An RCD can reduce electric-shock risk and, at suitable sensitivity levels, reduce fire risk caused by earth leakage. The name RCD alone does not confirm overload or short-circuit protection; always check the exact device type and markings.
What Is an RCCB?
An RCCB is a residual current operated circuit-breaker without integral overcurrent protection. It compares the current leaving and returning through the protected conductors and trips when residual current exceeds its operating threshold.
Important: an RCCB cannot protect cables against overload or short circuit. It must be coordinated with a suitable MCB, MCCB or fuse.
RCCB vs RCBO: The Choice Most Buyers Need
An RCCB provides residual-current protection for one or more circuits and needs separate overcurrent protection. An RCBO combines residual-current, overload and short-circuit protection for an individual circuit.
- Choose RCCB plus MCBs when several circuits can share leakage protection and group disconnection is acceptable.
- Choose individual RCBOs when circuit continuity and easier fault isolation are priorities.
- Check rated current, short-circuit coordination, conductor protection and manufacturer data as one system.
How to Choose the Correct RCD Type
Type AC, A, F or B
- Type AC: detects sinusoidal AC residual current. Its use is restricted or discouraged in many modern installations.
- Type A: detects sinusoidal AC and pulsating DC residual currents and is a common starting point for modern loads.
- Type F: intended for certain single-phase variable-frequency equipment and mixed-frequency leakage.
- Type B: detects smooth DC and other waveforms and may be required for particular PV, EV, UPS or drive applications.
Always follow the appliance, inverter or EV charger manufacturer’s instructions. Choosing Type B simply because a load is electronic can add unnecessary cost; choosing Type AC where DC components are possible can create a protection gap.
Residual Operating Current
| Sensitivity | Typical objective |
|---|---|
| 10 mA | Special high-risk or limited circuits |
| 30 mA | Additional personal protection |
| 100 mA | Upstream or fire-risk applications |
| 300 mA | Fire protection or upstream selectivity |
Higher-sensitivity upstream devices do not replace 30 mA additional personal protection where it is required. Cascaded RCDs should be coordinated for sensitivity and time delay to improve selectivity.
Standards and Safety Checks
- RCCBs are commonly covered by IEC/EN 61008-1.
- RCBOs are commonly covered by IEC/EN 61009-1.
- Use the test button at the interval stated by the manufacturer and local rules.
- If an RCD trips repeatedly, do not keep resetting it without investigating the fault.
- Final design and installation should be completed by a qualified electrician.
Frequently Asked Questions
Is an RCCB better than an RCD?
No. An RCCB is a type of RCD. If integral overload and short-circuit protection is required, compare RCCB with RCBO.
Can an RCCB work without an MCB?
An RCCB requires suitable overcurrent protection, normally provided by an MCB, MCCB or fuse. Coordination must follow manufacturer data and applicable standards.
Which is better for a house: RCCB or RCBO?
Both can be correct. RCCB plus MCBs can be cost-effective for grouped circuits. Individual RCBOs improve fault isolation because one leakage fault is less likely to disconnect unrelated circuits.
Does a 30 mA RCD make electric contact safe?
No. It provides additional protection but does not replace insulation, earthing, bonding or safe working practices.
Need Help Choosing?
Review Kuangya’s RCCB range and RCBO options. For selection support, provide your voltage, phase, rated current, load type, required residual-current type and applicable standard.
