Low Tension (LT) panels are the backbone of power distribution in industrial and commercial facilities. Selecting the wrong panel type — or under-specifying its ratings — can lead to costly downtime, safety incidents, and expensive retrofits. This guide walks through the main panel types and how to match them to your requirements.
Understanding the Panel Types
Power Control Centre (PCC)
A PCC receives power directly from the main transformer and distributes it to Motor Control Centres (MCCs), sub-distribution boards, and large individual loads. It is the first point of LT distribution in the facility and must handle the full incoming fault level. PCCs are typically rated from 630A to 6300A and above.
Motor Control Centre (MCC)
MCCs are downstream of the PCC and control groups of motors and smaller loads within a specific area or process. They incorporate individual motor starters (direct-on-line, star-delta, or soft-starter/VFD), protection relays, and metering. MCCs can be fixed or draw-out type, with draw-out offering superior maintainability.
Intelligent MCC (IMCC)
IMCCs add a digital communication layer — typically Modbus, Profibus, or EtherNet/IP — to a conventional MCC. Each module reports real-time current, voltage, power factor, and fault status to a SCADA or DCS system. This enables predictive maintenance, remote control, and energy optimisation without local operator intervention.
Key Selection Criteria
- Fault level (kA): Must match the prospective short-circuit current at the installation point
- Rated current (A): Full-load current of all connected loads plus a 20–25% growth margin
- Protection class: IP42 for indoor, IP55 for dusty/humid environments, IP65 for outdoor
- Busbar material: Copper preferred for reliability; aluminium for cost-sensitive applications
- Withdrawable vs. fixed: Withdrawable modules reduce maintenance downtime in critical plants
- Standards: IS 8623, IEC 61439-2 form compliance (Form 1 to Form 4b)
“Never specify a panel solely on cost. The total cost of ownership — including maintenance, energy losses, and downtime risk — almost always favours a properly rated, higher-quality panel.”
— Adarsha Engineering Team
Form of Separation
IEC 61439 defines four forms of internal separation that determine how well a panel isolates live busbars and functional units from each other. Form 1 offers no internal separation and is only suitable for low-risk, accessible installations. Form 4b — the highest level — provides complete separation between all functional units and the busbar, enabling live work on adjacent modules.
- Form 1: No separation — small, low-risk panels only
- Form 2: Busbar separated from functional units
- Form 3: Functional units separated from each other
- Form 4b: Full separation, including terminals — industry standard for critical plants
Working with Adarsha
Adarsha Control Systems manufactures PCC, MCC, IMCC, HT panels, DG synchronisation panels, and outdoor enclosures to IS and IEC standards. Our engineering team conducts load flow and fault-level studies to recommend the correct panel configuration for your facility before fabrication begins. Get in touch to start your panel selection process.