Low voltage switchgears series KRU-0.23k, KRU-0.4k

Serviceability

User-friendly control combined with active color LED symbolic circuit on the panels allows operational staff to be easily informed about condition of power supply circuits of metro power consumers.

Safety

Circuit-breaker controls in input and switchgear section cabinets are located on cabinet front side and protected by transparent door, excluding accidental contact with equipment live parts. Controls of switchgears outgoing lines distribution cabinets are located behind the door. Conductive parts are located behind protection screens and there is no possibility of operational staff electric shock during routine switchings.

Environmental compatibility

For switchgears production Pluton uses materials and component parts with no toxic agents and impact on human health and environment. Switchgear environmental compatibility is provided not only during operation, but also at the end of product life.

Structurally each switchgear consists of several rigidly connected standard one-sided maintenance cabinets (or double-sided maintenance upon request).

Switchgear power part is made with application of maintenance-free contact joints technology. Due to special compensating devices produced in Germany, contact joints clamping is regulated irrespective of temperature and thermal expansions. Application of this technology increases reliability of contact joints in equipment, and fire safety of switchgears and substation as a whole.

Switchgears protection level is IP54 according to IEC 60529. It limits dust ingress into switchgears, decreases operation costs for maintenance, increases operation reliability, as dust can cause overlapping of live circuits upon insulation surface. This solution sufficiently reduces fire risk.

Switchgear cabinets surface is made with triple surface treatment that provides resistance to mineral oils, greases, machine emulsions, lean acid and alkaline solutions.

Switchgear cabinets are equipped with microprocessor industrial controllers produced by B&R (Austria). They provide interlockings monitoring, circuit breakers drives control, communication with upper level control systems.

Insulation control in switchgears is provided by insulation monitoring devices produced by Bender GmbH&Co. KG (Germany) and Socomec UPS (France) or similar devices.

Insulation resistance value is indicated by LED light on the front panel of device and by indicator, and upon insulation decrease below set limits hardwires in external signaling circuit close.

Insulation monitoring devices have exit to RS-485 network allowing to transmit insulation resistance values, warning and emergency signals to operator.

Measuring and monitoring of electric parameters in KRU-0.23k and KRU-0.4k is provided by digital multimeters produced by Lovato Electric S.P.A. (Italy) and Socomec UPS (France). Measured values are displayed by means of digital LED indicators on devices front panel.

Schneider Electric (France), ABB (Germany) or similar circuit-breakers are installed in switchgears as power electric equipment. Withdrawable, plug-in or fixed circuit breakers can be applied in the switchgear cabinets.

Benefits of circuit breakers applied in the switchgears:

• molded housing with high resistance to shock and vibrations providing long lifetime;
• electromagnetic compatibility;
• can be applied in tropical climate.

Main features:

• double insulation, complete separation of power and auxiliary circuits;
• selectivity that allows selecting only fault area, providing maximum uninterrupted operation;
• circuit-breaker operation doesn’t depend on pressure and closing speed;
• access to arc chutes, moving and fixed contacts is provided by simple removal of circuit breaker cover that quickens maintenance and increases safety.