Internal ARC Resistant design

An arc fault normally begins as a short circuit between two or more contact points and quickly develops to pose a serious threat to personnel safety with an internal core temperature of 3000�C; an arc lasting just 500 ms can cause tremendous damage.
UNIPOWERLV LV switchgear offer you internal Arc withstand switchboards complying with IEC 61641

Features & Applications

• Personal safety for the operator and maintenance personnel
  In UNIPOWER LV switchboard our first priority is that an arc fault should be prevented from occurring in the first place by designing the switchboard still absolute reliable
• Plant safety in order to limit the damage within one system and to quench the internal arc within specific areas and functional compartments.
  If it occurs our second priority is by limiting the arc to the compartment where it occurs to minimize the damage. To achieve this, we have incorporated the following design concepts:
• Separate compartments for Busbar, distribution busbar and functional units.
• Insulated Busbar system
• Clearance and Creep age distance maintained higher than the standard latest IEC61439
• Spring loaded locking device
• Single phase isolated contacts

Earth Quake, Vibration and Shock

� UNIPOWER LV switchboards is successfully tested according to IS 1893 (Part 1) for highest seismic Zone V

Form 4 Switchboards

• The internal separation increases the safety for the personnel and the plant. Protection against direct contact can be obtained by appropriate constructional measures on the assembly itself. The risk to cause an internal arc failure is minimized.
• UNIPOWER LV switchboards provides up to form 4B type 7 highest forms of separation as per IEC 61439

Neutral Busbar Dimensioning

• UNIPOWER offers TPN/4Pole bus bar system as a standard option, preferred neutral conductor option include 50% or 100% of the phase conductor. It is also possible to select a conductor rating up to 200%.

UNIPOWERcomplete range is type tested with 100% fault level as of main bus bar.

Mechanical Design

� UNIPOWER LV switchboard are being manufactured with 100% bolted, modular construction with �C� shaped steel profiles with a 25 mm hole pitch.

Interleaved Busbar System

UNIPOWER LV Switchboards above 1600 A ratings are provided with interleaved system.

Advantages:

• Offer lower impedance and also impedance of each phase is fairly even. Which results in uniform temperature rise in all three phases.
• Reduces dynamic forces caused during short circuit, enabling the system to withstand much higher fault levels
• The interleaved bus bar system enhances the bus bar current carrying capacity
• Reduced power loss leads to energy savings & reduction in temperature rise
• Remove skin effect and proximity effect

Bus bar and Bus bar Supports

Horizontal bus bar runs through the length of LV switchboard at the top in a district zone. Aluminum / copper bus bar of EC grade E91E are provided.

Bus bar Supports

Bus bar supports are moulded from fiberglass reinforced thermosetting plastic.

• Bus bar and droppers are provided with heat shrunk PVC sleeves
• 'Click-fit' joint shrouds (optional accessories) used to cover tap-offs and fish plate joints.
• Interface barrier in bus bar and dropper zones can be offered on request.

Auxiliary Bus bar

Up to 12 auxiliary copper bus bar can be accommodated in the auxiliary bus bar chamber