Author: Jerome McEvoy, principal electrical engineer, Anord Control Systems Ltd Dundalk-based Anord, founded in 1969 and originally a domestic-based company, entered the international market in 1982, manufacturing its own product line. In May 2008, it announced the introduction of its unique Modular LV Switchgear System. Research and development by Anord Engineering is ongoing with a number of recent major product advancements, including UL-certified modular Form 4B Type 7 switchboards and the first in the Industry to fully meet the new British Nuclear Industry Standard. Featured here are the technical aspects of the AMS. The ever-changing developments within industry put very exacting and demanding requirements on electrical switchgear. Modern electrical switchgear must operate safely over its life and be flexible to allow adaptation to facilitate changes in process requirements. The Anord Low-Voltage Switchgear System has been designed to meet these requirements and is particularly suitable for applications within power distribution, water utility, sewage treatment, pharmaceutical, nuclear, manufacturing and retail industries.

Switchgear features

The Anord Low-Voltage Switchgear System has been developed from our previous system, which has proven itself over 20 years. In developing this, we have drawn on the strong points of the existing system and incorporated new thinking and customer feedback to achieve a flexible, safe and robust version which is future proofed for years to come. The enclosure system is constructed from maintenance-free screw joints to give a long service life. The system design allows for flexibility in cubicle arrangement to facilitate the incorporation of a wide range of components and applications. The modular approach to construction also facilitates on-site modifications and alterations to allow the system to be adapted to changing site requirements. The design of the busbar system allows for total versatility with the options to mount the horizontal busbar in the top, middle or bottom of the panel. The location can also be changed through the panel to facilitate different cable-entry requirements. The vertical feeder busbars can be arranged for front or rear access. The horizontal and vertical busbar systems are fully segregated to greatly reduce the possibility of internal arcing developing within the busbar systems and the materials used also assist in arc quenching within a short time. New PictureThe busbar systems can be offered with bare, tinned or insulated copper with 100% neutral rating as standard. All joints within the busbar system are pressure bolted and can be offered as maintenance free option if required. The system can be offered as straight line, double fronted, back to back, U shaped and in close coupled package substation configurations. The standard height is 2250mm but higher and lower options can be offered. The steel construction consists of a 3mm plinth, 2mm uprights and 1.5mm folded doors and panels. Equipment mounting plates are 2mm. Hinges allow for 180° opening and door locks can be offered as tri lock, T lock and lockable T lock. All main-frame steelwork is galvanised finished. Doors are offered as standard in RAL 7035 but other colours are available on request. AMS is a Type Testes Assembly (TTA) designed and tested to meet the requirements of IEC-60439, ISEN-60439 and BSEN 60439 and IEC-61439, ISEN-61439 and BSEN-61439.

Environment

AMS type switchgear is suitable for installation in protected locations for electrical equipment and other operating equipment in accordance with their degree of protection (up to IP 54). The switchboard is to be installed in a location where the ambient temperature does not exceed 40°C or where the average ambient temperature does not exceed 35°C over a 24-hour period. The lower limit for ambient temperature is -5°C. Higher ambient temperatures can be applied; however, derating must be applied to the busbar system and the components. Specific component limits must be observed in all cases. With regard to atmospheric conditions, the air should be clean and the relative humidity should not exceed 50% at a maximum temperature of 40 °C. Higher humidity levels may be permitted at lower temperatures, for example 90% at 20°C. Care should be taken to prevent condensation occurring as a result of temperature changes. Suitable for installation up to 2000 m above sea level. For higher locations, derating must be applied. A space of at least 100 mm should be left behind the panels to assist ventilation. 500 mm must be left above the panel. This space requirement is essential to allow any possible arc-pressure or gases to be released upwards and away from the operator.

Technical Data
Standards Type tested switchgear assemblies (TTA)* IEC 60439, BSEN 60439,ISEN 60439,  IEC 61439, BSEN 61439, ISEN 61439
Electrical Rated voltages Rated insulation voltage Ui 1000 V 3~
data Rated operating voltage Ue Rated impulse withstand voltage Uimp 690 V 3~12 kV
Overvoltage category IV
Degree of pollution 3
Rated frequency up to 60 Hz
Rated currents  Busbars: Rated current Ie Rated peak withstand current Ipk Rated short-time withstand current Icw     3 second withstand50kA Icw / 120kA Ipk up to 6300A In1 second withstand80kA Icw / 176kA Ipk up to 3200A In100kA Icw . 220kA Ipk up to 6300 A In        
Mechanical characteristics Dimensions Cubicles and supporting structures 2278 mm
Width 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200 mm
Depth 680, 980, 1280 mm
Surface protection Frame Galvanised coated
Internal subdivision Galvanised coated
Transverse section Galvanized
Enclosure Paint RAL 7032, light-grey standard, customer specified colours available.
Degrees of According to EN 60529 IP 31 up to IP 54
protection
Insulating components PVC & Polyolefin flame-retardant, self-extinguishing.
Internal Up to Form 4 Type 7 according to BSEN 61439 Table N.A.1 Forms of Separation
subdivision
Extras Paint Enclosure Special colours (standard RAL 7032)
Busbar system Busbars Insulated (standard is bare)
Seismic Qualification Tests Customer specified test criteria can be tested.
* Definition TTA: A low voltage switchgear and control gear assembly conforming to an established type or system without deviation likely to significantly influence the performance, from the typical assembly verified to be in accordance with this standard.