|
|
- Separable Connectors
- Inner Cone Terminations
- Cold Shrink Joints
- Cold Shrink Terminations
- Stepless Shearbolt Connectors
Screened Separable Connectors
The concept of a slip-on three layer moulding of conductive and insulating EPDM rubber as a cable connector to equipment was originally patented in the late 1960s. The idea was so good there were several attempts to get round the patent with painted screens and varnishes, but none survived. The concept has stood the test of time and the original ANSI/IEEE 386 standard has been introduced into IEC, VDE, Cenelec and BS standards. RTE (now Cooper Power Systems) was one of the first manufacturers of these products and they also patented the ‘loadbreak elbow’ which is now synonymous with pad mount transformers.
The range of products has grown enormously with different countries favouring different product series but still maintaining the same basic concept. Most MV distribution equipment these days is designed to accept screened separable connectors. |
|
|
 |
The advantages are:-
Simplicity of installation:
- Installed in minutes, no heating, potting or taping.
Reliability:
- Each connector is factory tested prior to dispatch.
Compactness:
- Being fully screened all three phases can effectively touch.
Safety:
- Once installed they are watertight and touchable (Check local Supply Regs.)
Disconnectability:
- Readily disconnectable for equipment isolation testing or earthing.
|
The demonstration panel on the right shows the 200 series deadbreak straight and elbow connector very commonly used on European distribution transformers. Below these are the 400 series elbow and bolted tee connectors fitted now as standard on most European switchgear. |
|
 |
| |
|
The product shown at the top right of the demonstration panel on the right is the famous 200 series loadbreak elbow, as fitted standard on all America's distribution transformers. It is now becoming popular on pad mount transformers in the UK because of its flexibility of operation. Below this is an example of the 600 series product terminating two cables per phase. This is a popular application on the 11KV side of Primary Substation Transformers in the UK. The lower right bolted tee connector is the 700 series 36KV product used extensively in trackside substations in the UK and on the 33KV side of Primary Substation Transformers.
|
|
 |
| |
|
These 700 series 35KV Bolted Tee Connectors are terminating 33KV 185sq mm cable onto a trackside transformer. No further protection is required. This has been the standard termination arrangement for British Rail and now RailTrack for more than 10 years and there are in excess of 1000 units in service.
|
|
 |
| |
|
|
Pfisterer Connex Inner Cone MV cable system 10kV – 52kV
The MV Connex range is ideal for use in ring main units, circuit breakers, high voltage motors, capacitors, transducers, sealing boxes and cable joints. The connectors on the equipment side are designed to meet the requirements of EN 50180, 50181 and DIN47637. The plug is suitable for all kinds of insulated plastic cables. In addition to a wide range of standard products there are also customer-specific versions, cable jointing systems, surge arresters and variations for all types of tests encountered in network construction.
The Connex cable termination systems include Connex inner cone separable connectors and bushings in sizes, 0,1, 2, 3 and 3S requiring the connector to be plugged into the bushing and bolted mechanically. The system must be de-energised when installing or removing the Connex plug.
Connex meets all the requirements of a universal connection system. It is fully insulated, metal-enclosed, safe to touch, zero maintenance, submersible and durable for outdoor use. These characteristics make Connex suitable for even the toughest conditions.
|
 |
|
 |
|
Cold Shrink Technology
The essence of Cold Shrink technology is its classic simplicity - it moulds round a joint or termination under its own elasticity without the need for special tools or techniques. Its secret lies right inside every 3M Cold Shrink component in the form of a plastic coil. After the component has been placed over the joint or cable end, this inner spiral is pulled out. The insulating tube then contracts from its pre-stretched size and shrinks onto the cable, exerting permanent radial pressure for the lifetime of the joint.
The simplicity of design is matched by the complexity of the research that has 3M has put into the material developments over the last three decades. Silicone rubber is today’s choice for 3M. It is hydrophobic, or averse to water - particularly important in outdoor terminations. Water on the surface forms droplets rather than spreading into an even film that can increase the chances of tracking or insulation breakdown. Silicone is mostly inorganic, so leakage currents or arcing on the surface do not create a conducting carbon path. As an additional safe guard, 3M uses track-resistant filler. Silicone is UV-stable without the need for inhibitors while its smooth surface provides minimal grip for contaminants so rain will wash them away. |
Joints & Terminations
QTIII Terminations
These terminations offer easy installation and reliable performance when terminating indoor and outdoor medium voltage cables. QTIII is a one-piece silicone rubber termination, which is expanded and loaded onto a removable supporting core, which allows the termination to be installed without the need for tools or heat. The core is stepped to allow a greater application range for armoured cables.
The termination body itself consists of a tubular silicone insulator, with a built in refractive stress |
|
control tube and compound, and a built in top seal. Due to this unique design the product is installed in one operation without the need for any additional components. QTIII terminations are suitable for use on polymeric cables medium voltage up to 72kV. Both indoor and outdoor terminations are available for single core and three core cables. QTIII terminations have been tested in accordance with IEEE Std 48- 1990, VDE 0278 Part 4 and IEC/CENELEC. Details of type tests are available upon request. |
Features
- One-piece termination
- Built in stress control compound
- Built in top seal
- Moulded rain sheds on outdoor terminations
- Optimum High-K stress control
- Compact design
- High reliability, over 20 years of proven fi eld experience
- Continuous operating temperature of 90°C, overload rating 130°C
QS1000 & QS2000 Joints
3M QS1000 and QS2000 one-piece cold shrink joint bodies are manufactured from a specially formulated silicone material, which provides flexibility, easy installation at low temperatures and superior electrical performance over a wide range of operating temperatures. Just like the QTIII termination, the finished body is expanded and loaded onto a removable supporting core, which allows the joint to be installed without the need for tools or heat. |
|
 |
3M QS1000 and QS2000 bodies are injection moulded and consist of three layers.
a) a semi-conductive electrode, which forms a Faraday Cage around the connector,
b) a high permittivity insulation layer, which both insulates and stress controls,
c) an outer semi conductive layer which ensures all screens are at earth potential.
* In the QS2000 body it also has two inner stress control elements to provide the proper electric field distribution for the higher voltage classes.
All finished bodies are tested after manufacture and undergo AC Withstand and Partial Discharge testing. All joint types have been tested in accordance with VDE 0278, HD 629 and/or BS7888. Details of type tests are available upon request. |
|
 |
Features
- One part joint body
- 100% tested after manufacture
- No heat required
- Tool free installation
- Permanent radial pressure
- Suitable for paper and polymeric cables
- Compatible with compression and mechanical connectors
- Low temperature installation
- Provides consistent installation quality
- The inner semi–conductive electrode electrically surrounds the high voltage connector eliminating the use of tape or additional moulded or metallic electrodes
|
Stepless Shearbolt Connectors and Cable Lugs
Shearbolt connectors and cable lugs have grown in popularity in
recent years mainly due to the fact that bolted connections offer technical and practical advantages that compression connectors cannot provide. This coupled with shearbolt technology obviating the need to maintain and calibrate large compression tools is a distinct advantage to the end user.
Until now the ‘multi-stage shearbolt’ has been the standard in
screw technology. The previously thought design strength of the integral predetermined breaking points is at the same time a decisive weakness. Each breaking point interrupts the load breaking thread and the maximum clamping force cannot always be achieved. Also, if the breaking points are not accurately matched to the conductor being used, the bolt will shear either too low or too high. |
|
 |
New from Langley Engineering
Pfisterer SICON stepless shearbolt connectors and cable lugs incorporate an innovative design feature that ensures optimum thread loading for any range of cross sections. Having no predetermined break points means the bolt always shears directly at the surface of the connector body. No special tooling is required and cables from 10mm2 – 630mm2 can readily be accommodated. [larger sizes are available on request]
|
|
 |
|
|
| |
Langley Engineering Ltd - Medium Voltage Equipment for the Electricity Industry
16 The Markham Centre, Theale, Reading, Berkshire RG7 4PE - Tel: 0118 9305990 |
|
|
