KEYS, 1000 TYPE | |||||||
GPO ETL / Plessey These keys are a miniaturised version of the standard lever key and are called the 1000 type. Introduced in the late 1960's on new equipment and produced by ETL / Plessey. The key mechanism is all plastic except for the mounting frame and the spring loaded lever saddle. Contacts are mounted on both sides and are operated at the same time by a central lever mechanism. The key can be in one of three positions and can be locking or non-locking in two positions. The contacts are normal when the key is upright. The handle is held in place, on top of two plastic formers, which are located on two metal pins (hidden under the handle), which can allow the handle to rock both ways. The handles can be supplied where they rock in one direction only. The plastic formers rest on arms which operate the contacts. The arms in turn rest on the central sprung loaded metal saddle and this keeps the whole mechanism under tension. The lower ends of the arms can be either angled or flat (or both). An angled end will cause the key to lock when pushed in that direction, whilst a flat end will be non-locking (see single key picture below). When operating these keys a handle should always by in place. This ensures that the formers are held in place and stops them spreading outwards, due to the pressure of the spring. Types
Switching Action Contact Rating Note: Contact ratings given are for non-inductive loadings only. Adequate spark quenching must be applied when connecting into inductive circuits. Connection Contact Units Handles Spring Numbering Mounting
Plessey N24209, N9300 and 9400
Plessey N9900
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Last revised: November 18, 2021FM |