The horizontal break knee type disconnector consists of three poles. Each pole consists of a base, one rotating insulator and two support insulators on which the main blade is mounted.
The base is made of steel plates on which the insulators are mounted. The individual bases are connected by means of a tie rod. All steel parts of the disconnector are hot-dip galvanized.
The disconnectors can be equipped with insulators in accordance with IEC, ANSI or DIN specifications.
The main blade is made of 2 aluminium tubes with a hinge in the middle and have silver-plated copper contacts at the jaw end. During closing of the disconnector, the main blade make a horizontal stretching movement.
Full contact pressure of the main contacts is achieved by full stretching of the main blade.
- The main contacts are of the “reverse-loop” design, which makes them suitable for very high short circuit currents.
- All contacts are made of silver-plated copper and are equipped with stainless steel springs to ensure reliable contact pressure.
- The main terminals are made of flat aluminium and can be drilled as per request.
- Depending on the voltage rating, anti-corona shields will be provided.
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.
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.
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).
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.
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.