Frame The frame is made of a square tube in which in the center the bearing housing and the turntable are installed. The turntable is supported by two roller bearings. The bearing housing is sealed and filled up with grease, to ensure a long lifetime. All steel parts of the disconnector are hot-dip galvanized. Insulators The disconnectors can be equipped with insulators in accordance with IEC, ANSI or DIN specifications. Main blade The main blade consists of two fixed contacts, mounted on the suppor­ting insulators, and a moving blade mounted on the rotating in­sulator. The main contacts are installed inside the main blade. They are made of copper, with a silver-plated surface. Each contact finger is provided with stainless steel springs to ensure reliable contact pressure. The contacts are self-cleansing, which makes the disconnector suit­able for installation in areas with severe climatic conditions. Depending on the voltage rating, anti-corona shields will be provided. Earthing switch Hapam disconnectors may be equipped with earthing switches, which can be built-on to the right hand side and/or to the left hand side. The earthing switch consists of an Aluminum tube, provided with silver-plated contacts at both ends. Drive mechanism The disconnectors and/or earthing switches can be single-pole or three-pole operated by means of a motor-operated drive mechanism or a manual-operated drive mechanism. In case only one drive mechanism is used for three-pole operation, the poles are interconnected by means of adjustable coupling rods. The drive mechanism also houses the auxiliary contacts for position indication. Testing The disconnectors and earthing switches are designed and tested in accordance with latest IEC specifications. Hapam main­tains a q­uality assurance system according to ISO 9001, certified by DEKRA (previously known as KEMA). Installation The disconnectors and earthing switches are pre-assembled and ad­justed in our works as complete as possible. The construction is designed so that all disconnectors can be instal­led and adjusted at site very easily, without the need of any special tools. Hapam provides clear installation instructions and assembly drawings. Maintenance The disconnectors and earthing switches supplied by Hapam are d­esigned so as to ensure that they are virtually maintenance free. However, to warrant a long and trouble-free service period, we advise that a visual inspection of the contacts and bearing points be carried out at regular intervals.