The WRU-10 RAL is the automatic self-reclosing version of the WRU-10, with the toroidal transformer built in as a Ø28 mm aperture through which the circuit conductors pass directly — relay and transformer in one three-module device, with no separate toroid to size, order or wire. Automatic reclosing is the point of the RAL variant. The great majority of earth faults on an outdoor or buried circuit are transient — moisture, a wind-blown branch, a momentary flashover — and clear themselves the instant the circuit is opened. A conventional relay treats those identically to a failed cable and leaves the load off until someone attends. This device re-closes on a programmed sequence of attempts, restoring supply in seconds, and locks out only if the fault is still present after the sequence, which is precisely the behaviour wanted on street lighting, pumping stations, irrigation, telecoms cabinets and any other unmanned site where an attendance costs more than the outage. Sensitivity and delay are adjustable. It is a type A device: it responds to sinusoidal AC residual currents and to pulsating DC residual currents. Circutor specify it as superimmunised, with high-frequency filtering and true RMS (TRMS) measurement, so that the harmonic leakage normal in an installation full of switch-mode loads does not read as a fault. Manufactured by Circutor (Spain) and supplied under the Function brand; the Circutor catalogue reference is WRU-10 RAL. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.