
Centre-Break Disconnectors
Type SSBII up to 550 kV

The horizontal centre-break disconnectors consist of three poles. Each pole consists of a frame, two rotating support insulators and a main blade that moves in a horizontal plane.
• More than 75 years of experience
• Durable and reliable design
• Over 120,000 disconnectors and earthing switches are in service in more than 100 countries throughout the world
• Virtually maintenance-free
• More than 75 years of experience
• Durable and reliable design
• Over 120,000 disconnectors and earthing switches are in service in more than 100 countries throughout the world
• Virtually maintenance-free
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.
Insulator
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 consist 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 the latest IEC specifications. Hapam maintains a quality assurance system according to ISO 9001, certified by DNV GL(previously known as KEMA).
Installation
The disconnectors and earthing switches are pre-assembled and
adjusted in our works as completely as possible. The construction is designed so that all disconnectors can be
installed and adjusted at the 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 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.
| Rated Voltage | kV | 72.5 | 123 | 145 | 245 | 550 |
|---|---|---|---|---|---|---|
| Lightning Impulse Withstand Voltage | ||||||
| to earth | kV | 325 | 550 | 650 | 1050 | 1550 |
| across the isolating distance | kV | 375 | 630 | 750 | 1200 | 1550 |
| + 315 | ||||||
| Power Frequency Withstand Voltage | ||||||
| to earth | kV | 140 | 230 | 275 | 460 | 620 |
| across the isolating distance | kV | 160 | 265 | 315 | 530 | 800 |
| Lightning Impulse Withstand Voltage | ||||||
| to earth | kV | – | – | – | – | 1175 |
| across the isolating distance | kV | – | – | – | – | 900 |
| + 450 | ||||||
| Current and Short Circuit Ratings | ||||||
| 1600 A-80 kA peak-32 kA/3 sec | ||||||
| 2000 A-100 kA peak-40 kA/3 sec | ||||||
| 3150 A-125 kA peak-50 kA/3 sec | ||||||
| 4000 A-160 kA peak-63 kA/3 sec | ||||||



