Schmersal Has developed the switch of hygiene ZSM 241 with enclavamiento apt, for example, for the unemployment of electrical emergency of the system of traction of an elevator in case of excess of speed.
The series ZS 231 of Schmersal represents a range of switches of hygiene perfectly adapted to the needs of the sector of elevators, with a big number of units in service all over the world. The precarrera of these switches is of only 0,2 mm.
The switch ZSM 241 shares the main basic elements of the model ZS 231, although executed like switch of position enclavable with remote release. After commutating the switch to the opposite final position, enclava. The release realises by means of a solenoid, that can receive remotamente the electrical signal of performance, for example, from a pulsador situated in a signpost of external control. It is ideal to realise the unemployment of electrical emergency of the system of traction, that takes part when the limitador mechanical situated in the head of the pozo detects an excess of speed of the cabin of the elevator. In this case, it is accionado by the centrifuges mechanism of the limitador, whose active signal the brake of the engine, so that it is not necessary to activate the brake of emergency of the cabin.
By reasons of hygiene, the brake of the engine remains activated until it locates the cause for the excess of speed of the cabin. Once detected the failure, the switch of hygiene frees . Since the limitador, that adjusts and verifies especially for each elevator, works according to the centrifuges principle, the ZSM 241 has to work with the maximum precision. This means that before it shoot the limitador of speed, the brake has to act on the system of traction.
This application of the ZSM 241 does recommended a system of remote release, since the systems of traction and, with them, also the limiters of speed install increasingly directly in the gap, in place of separately in a room of machines. Of this form, the direct access to the limitador results impossible. If it installs the switch of hygiene ZSM 241, this can free simply through a pulsador situated in the signpost of control, with what avoid risks for the operarios and the service of the elevator reestablishes before.
Another application of the ZSM 241 can be the control of the unblock of emergency by triangular key in the door of ship of the inferior flat, to end to avoid that an operario can remain shut inside the pozo: When unblocking the door of the first flat, the switch changes and, although the door close , the elevator can not set up until the operario have freed the ZSM 241 by means of a key of external reset. The precarrera of manoeuvre extremely short of the ZSM 241 ensures that active with the maximum reliability to the accionar the unblock manual.
The measures in work, so much of the ZSM 241 as of the ZS 231, fulfil the norm IEC 60947, by what the replacement of a ZS 231 or the installation in an existent elevator does not present greater problems. Besides, the supply of the switch with all the cables of connection ensures an easy and fast setting. In summary, the ZSM 241 presented by Schmersal constitutes a device of special manoeuvre for elevators, perfectly adapted to the exigencias practical and that contributes to the increase of the hygiene in the operation and maintenance of elevators.