EXB9L-125 RCCB
Graded Protection — Selective & Surge-Immune RCCB for Cascaded Systems
The EXB9L-125 Type S and SI are selective residual current circuit breakers for installations where several RCCBs sit in series. A built-in time delay coordinates the devices so that only the RCCB nearest to the fault trips, keeping the rest of the installation live, while SI versions add filters against harmonics and transient surges.
Model
EXB9L-125 Series — Type S / SI Selective RCCBEXB9L-125 1P+N / 3P+N · Type S · Type SI · IΔn 30/100/300mA
IEC/EN 61008-1 · selective (time-delayed) · surge immunity · DIN rail
Product Details
- Selective (time-delayed) RCCB for upstream positions in cascaded residual current protection schemes.
- Fitted with filters against spurious tripping caused by harmonics and transient surges.
- Withstands an 8/20µs surge of 3000A without unwanted tripping, keeping the supply stable during lightning activity.
- Rated current 16, 25, 32, 40 and 63A; sensitivity 30mA, 100mA and 300mA available.
- Type S responds to sinusoidal AC and pulsed DC residual currents; SI versions add anti-interference filtering.
- 1P+N (230/240V) and 3P+N (400/415V) versions; insulation voltage 500V; impulse withstand 4000V.
- Status window showing open (white) and closed (red) states; fault current indicator.
- DIN rail 35mm mounting with dual busbar terminals and 2.5N·m tightening torque.
Product Information
Key Features & Typical Use
Trip Only Where the Fault Is
Due to its time delay feature, the Type S device gets to wait for the RCCB downstream to eliminate the fault. This creates a graded type of protection whereby a fault in a circuit trips only that particular circuit.
Built-In Immunity to Harmonics and Surges
Filters eliminate harmonics and transient surges which cause misoperation of typical RCCBs, making it one of the most frequent reasons for nuisance tripping in businesses.
3000A Surge Withstand
A current surge of 3000A with 8/20µs of pulse duration is observed without tripping, which is the level when lightning activity in the vicinity can be expected, as well as the switching operations from overhead-operated systems.
Same Frame as the Standard Range
The Selective models utilize the same housing, terminals and accessories as the EXB9L-125, which makes mixing selective and standard devices in a single line possible.
Specifications
| Parameter | Details |
|---|---|
| Series | EXB9L-125 Residual Current Circuit Breaker (Magnetic) |
| Types | Type S · Type SI (selective / time-delayed) |
| Standard | IEC/EN 61008-1 |
| Rated Current In | 16, 25, 32, 40, 63A |
| Rated Sensitivity IΔn | 0.03, 0.1, 0.3A |
| Poles | 1P+N, 3P+N |
| Rated Voltage Ue | 1P+N: 230/240V~ · 3P+N: 400/415V~ |
| Insulation Voltage Ui | 500V |
| Surge Withstand (8/20µs) | 3000A without tripping (SI versions) |
| Conditional Short Circuit Current Inc/IΔc | 10000 / 6000A |
| Break Time under IΔn | ≤ 0.1s at rated residual current |
| Impulse Withstand Voltage Uimp | 4000V |
| Dielectric Test Voltage | 2kV, 1 minute |
| Electrical / Mechanical Life | 4000 / 4000 operations |
| Terminals | Cable 25/35mm² (AWG 18-3/18-2); busbar 10/16mm²; torque 2.5N·m |
| Mounting | DIN rail EN 60715 (35mm) with fast clip; connection top or bottom |
| Protection | IP20 · pollution degree 2 · -25°C to +40°C |
EXB9L-125 Type S / SI — Protection That Knows Which Breaker Should Trip
One RCCB is sufficient for a residential installation. Meanwhile, a hospital floor, shopping center, or factory can have dozens of residual current devices connected in cascade, and due to lack of coordination, the wrong device will trip: for example, a malfunction in a shop unit behind the 30mA device will trigger the 300mA main upstream one and turn the power off in the whole building. Selective RCCBs are engineered to avoid this issue.
Type S RCCB has been designed with a time delay in the upstream device so that it can trip later than the downstream device. Type SI RCCB includes filters to get rid of noise and transients from variable frequency drives, LED lighting, and high-power switch-mode power supplies that could erroneously cause tripping due to noise. The surge withstand capacity of the Type SI RCCB is 3000A (8/20µs) and enables the device to cope with transients generated by lightning strikes.
Huyu produces EXB9L-125 devices in-house and sells Type S and SI devices to panel builders, infrastructure providers, suppliers, and OEMs at the manufacturer’s prices, with complete IEC/EN 61008-1 test certificates included.
Factory-Direct OEM / ODM Manufacturer
We Manufacture, You Brand
Since selective devices rely on precise timing, all EXB9L-125 Type S and SI units are calibrated for their sensitivity and time characteristics during production and then surge-tested on a sample basis before being shipped.
We offer matched sets for infrastructure projects with selective upstream and standard downstream devices so that their timing characteristics can be matched as well.
- OEM branding — marking, rating labels and packaging under your own brand.
- ODM options — sensitivity and time-characteristic variants for specific coordination schemes.
- Test documentation — time-current characteristic and surge test records supplied per batch.
- MOQ — flexible quantities; selective and standard devices can be mixed in one order.
Buying Guide
When it comes to selective RCCBs, these devices have to be in accordance with a certain order in the protection chain: the preceding device should provide slower response compared to the following ones and usually have lower sensitivity than that of the devices downstream.
- Map the protection chain: main incoming, sub-distribution, final circuits.
- Assign sensitivity: typically 300mA upstream, 30mA downstream.
- Specify Type S (or SI where drives and LED lighting are present) for the upstream position.
- Check the coordination time between the chosen devices.
- Confirm the upstream short-circuit protection that the RCCB relies on.
- Verify terminations — 35mm² cable or 16mm² busbar at 2.5N·m.
- Approve samples; production with timing calibration records.
How We Support Your Business
OEM / ODM
Sensitivity and timing variants with your own marking, backed by calibration and surge test records.
Private label · Timing variants · Test records
Wholesale
Factory-direct pricing on selective and SI devices for distributors serving commercial and infrastructure projects.
Factory pricing · Mixed orders · Global shipping
Distributor Support
Coordination guidance, selection tables and priority production for partners working on cascaded protection schemes.
Coordination help · Selection tables · Priority lead times
Ready to Stock the EXB9L-125 Selective Range?
By submitting one inquiry, you can receive a factory-direct quote for Type S and SI Selective RCCBs, complete with coordination information regarding cascade protection schemes and information regarding OEM/ODM pricing and distributor assistance.
Frequently Asked Questions
What is a selective RCCB?
Selective RCCB refers to a type of residual current device that includes a time delay in its trip feature. In installations that use multiple RCCBs connected in the same way, having this included in the design of the RCCB makes sure that the one closest to the source of the problem cuts off the power supply so that only a specific circuit is affected while the rest continue to function normally.
When do I need Type S instead of a standard RCCB?
The problem arises when two or more RCBS connected in series malfunction. All of them operate at nearly the same speed, hence the nearest device might not trip first. Type S device solves this issue as it is used anywhere upstream in larger installations.
What does the SI variant add?
System International (SI) introduces filters capable of eliminating tripping due to harmonics and transient surges — disturbances caused by electronics such as variable-speed drives, LED lamps, IT devices, and electrical switching operations. With 3000 A (8/20 µs) surge tolerance, an SI unit does not trip during surges that would trip an unequipped RCCB, resulting in higher reliability of operation free of unnecessary downtime.
Which sensitivities are available for the selective range?
The selective range is found in 30mA, 100mA, and 300mA varieties in the range of 16A-63A, with configurations available for both 1P+N and 3P+N systems. The common configuration is for an upstream 300mA Type S in conjunction with downstream 30mA standard devices to provide first-line fire protection at the beginning of the circuits and personal protection at the end of the circuits.
Does a selective RCCB still provide personnel protection?
Because of its delay feature, a selective device cannot provide adequate protection against the risk of direct contact by itself, which is due to the increase of exposure time. Protection of personnel makes use of 30mA devices in the final circuit while selective RCCB upstream protects against fire, property loss and provides level discrimination.
