General
The horizontal center-break disconnector consists of three poles. Each pole consists of a frame, two rotating support insulators and a main blade that moves in a horizontal plane.
Frame
The frame is made of a square tube in which the bearing housings and the turntables 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 a U-shaped profile, in which the main contacts and the rotating contacts are installed. The rotating contacts consists of a silver-plated copper pin and a bronze housing. Silver-plated bronze balls, which are pressed against these two parts by means of a stainless steel spring, ensure that the current is transferred from the pin into the housing. This contact construction is sealed and maintenance free. 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 aluminium 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.
