Contactor Relays

© Siemens AG 2012Coupling RelaysCoupling Relays with LZS/LZX Plug-In RelaysPlug-in relay couplers■ OverviewPlug-in relay coupling links can be ordered as complete units oras individual modules for customer assembly.FunctionThe semiconductor couplers have a low power consumptionand are therefore particularly well suited for solid-state systems.In the versions equipped with LEDs, these indicate the switchingstate. The LZS:PT/MT plug-in relay couplers have a test button.This can be used to force the plug-in relay coupler into theswitching state and to lock it. This is indicated by a raised petrolcoloredlever.Control with solid-state outputIn the case of solid-state outputs (e.g. proximity switches) withoverload and short-circuit protection, you must make allowanceduring configuration for the temporarily flowing capacitor chargingcurrents! This is possible, for example, by using a suitableLZS plug-in relay coupler.Surge suppressionThe 24 V DC relays LZX:RT and LZX: PT with LEDs can be suppliedwith, all others without integral surge suppression (freewheeldiode connected in parallel with A1/A2). The positive controlsupply voltage must be connected to coil terminal A1.MountingThe relays are plugged into the base and this is snapped onto aTH 35 standard mounting rail according to IEC 60715.A retaining bracket can be ordered for the MT series that additionallyfixes the relay into a plug-in base (under conditions of increasedmechanical stress). For the RT and PT series, a combinedretaining and ejection bracket is available which can beused to disassemble the relay where access is difficult, for example,when relays are mounted side-by-side.They can be mounted as required.Logical separationThe terminals for the contacts and the terminals for the coil arearranged on separate levels, e.g. above for contacts and belowfor coil. Logical separation is not necessarily protective separation.Protective separationFor safe isolation, transfer of the voltage of one circuit to anothercircuit is prevented to a suitable degree of safety (requirementsand tests are described in IEC 60947-1 in Appendix N).Notes on the previous LZX seriesThe complete units and accessory parts of the LZX series are nolonger listed in this catalog. The complete units of the LZS seriesare fully compatible with the corresponding units of the LZX series.Prices for the LZS series are lower than for the previousLZX series.The LZX plug-in relays are available unchanged and are usedaccordingly in both the LZS and the LZX series.Note:Due to differences in geometry the LED modules, plug-in bases,retaining brackets and labels can be combined and/or used inonly the respective series, LZS or LZX.The LZS series offers not only service-proven screw connectionsbut also versions with plug-in terminals (push-in).5Siemens IC 10 · 20125/53