High Quality WR2L-63 4P RCCB

It is a four-pole residual current circuit breaker for three-phase four-wire low-voltage systems, providing earth-leakage protection without built-in overcurrent protection. It continuously monitors the sum of the three phase currents and the neutral current through an internal core-balance current transformer, and trips when that sum exceeds the rated residual operating current.

All four conductors (L1, L2, L3, N) pass through a toroidal ferromagnetic core. Under normal load the phasor sum of the four currents is zero, so the magnetic flux in the core is zero and the secondary winding induces no voltage. An earth fault creates a nonzero residual current, producing a flux that induces a voltage in the secondary; this signal drives a sensitive electromagnetic release that opens the contacts.

"4P" means the device has four poles that open together — three phase poles and one neutral pole. When it trips, the load is disconnected from all three phases and from neutral, providing full isolation. It must be used on systems where all four conductors are live at once; do not use a 4P device as three single 1P devices, because the toroid sums all four conductors together.

The 63A (In) is the maximum continuous current the unit can carry per pole at rated voltage without unacceptable temperature rise. It is a thermal/contact rating, not a trip setting. Because the RCCB has no thermal-magnetic trip, the upstream protection (MCB/MCCB) must be coordinated to protect the cables and the device itself against overload and short-circuit.

Standard household/commercial 4P RCCBs use 30 mA for human protection, 100 mA or 300 mA for fire-prevention and equipment-leakage monitoring, and selectively delayed (type S) versions for discrimination between upstream and downstream RCDs. The exact IΔn is printed on the nameplate and in the datasheet.

Type AC trips only on sinusoidal AC residual current. Type A also trips on pulsating DC residual current (up to half-wave rectified DC). On three-phase loads containing variable-frequency drives, soft starters, battery chargers, or PV inverters, pulsating DC can appear on earth fault, so Type A or Type B is required. Pure Type AC is acceptable only on linear resistive three-phase loads.

Connect incoming L1, L2, L3, and N to the four marked IN terminals, and the same four conductors to the load from the OUT terminals. The PE conductor runs straight through the enclosure and must never pass through the toroid or be switched by the RCCB. Ensure the neutral is not shared with any other circuit on the load side, because any parallel neutral path creates a false residual current and nuisance tripping.

It is used as the main RCD at the origin of three-phase distribution boards in shops, offices, small factories, agricultural buildings, and commercial sites. It protects three-phase motors, compressors, three-phase air conditioning, and three-phase socket-outlet circuits. For large installations it is often paired with upstream type S RCDs so that only the faulty branch trips, preserving supply to the rest of the site.

It clips onto a standard 35 mm DIN rail and occupies four pole-widths. Press the "T" test button monthly to verify the trip mechanism; a non-tripping device must be replaced immediately. Annually inspect terminal torque, enclosure condition, and ambient conditions (temperature, humidity, dust). Keep the handle accessible and never enclose the device inside a sealed box without derating guidance.

The device is manufactured to IEC 61008-1 (RCCB without integral overcurrent protection) for rated voltages up to 440V AC and rated currents up to 125A. CE marking under the Low Voltage Directive and EMC Directive confirms product conformity for the EU and IEC-aligned markets. Always verify the declared rated impulse withstand voltage, tripping time/current characteristic, and the correct Type before installation.