CLIXTRAB is a surge protective device (SPD) integrated with a DIN-rail terminal block-the plug-in module is inserted directly into a base with a disconnect knife, without a separate base unit. The solution was developed for railways and declares compliance with Deutsche Bahn directive RIL 819.0808, which defines surge-protection concepts for electronic and digital interlockings. The two-position CLT-10P/2-VF-230V-I-P protects typical signalling and telecommunications circuits, while the four-position CLT-20P/4-VF-230V-I-P is intended for point machines. The electrical design permits operation in 230 V DC systems and three-phase 400 V AC systems at continuous currents up to 10 A. The protection level of a single module is Up ≤ 1.4 kV conductor-to-ground for test class C1 (1.5 kV / 750 A); in low-voltage 24 V variants it is ≤ 60 V between conductors and ≤ 900 V conductor-to-ground.
The series connection of a varistor and gas-discharge tube eliminates leakage currents and feedback coupling between conductors in the signal circuit, and the module can be unplugged without interrupting the circuit. Signalling installations usually operate as isolated systems that tolerate the first ground fault, so the DIN rail of all modules is isolated from earth and its potential is connected to the main equipotential bonding system through a separate FLT-SEC-P-T1-1C-440/35-FM combined surge protective device. The CLIXTRAB and FLT-SEC combination was tested for an operating voltage of 3~400 V AC with a continuous disturbance voltage of 250 V AC and a short-duration voltage up to 1500 V, as can occur if the overhead contact line breaks; the achieved protection level is 2.5 kV.
With the disconnect knife open, operating current can be measured using test plugs from the standard accessories, while insulation-withstand tests and ground-fault searches can be performed on the terminal base. Terminal components of the system have confirmed railway approvals: the PT 2.5-MT-CLT base complies with EN 45545-2 and NFPA 130, and the PTV 6-SG WH grounding terminal additionally meets EN 50155 in vibration test Category 2. The product standard for the surge protective devices is EN 61643-21. A mechanical indicator shows module operation, while the TTC-6-FMTX-PT and TTC-6-FMRX-PT set reports status to the diagnostic system through a potential-free contact.
