Control Panel
Types in India
— MCC, PCC, VFD & More

"We want a new panel for the factory" — but which panel? MCC? PCC? APFC? VFD panel? Many engineers in India use these terms loosely, but each panel has a specific function, standards, and design philosophy. Specifying the wrong type means safety hazards, regulatory issues, and re-work cost. This guide covers every major industrial control panel type used in Indian industry.

1. PCC — Power Control Center

The PCC is the main incoming panel after the transformer. It receives high-current LT power (usually 415V AC, three-phase) and distributes it to downstream panels (MCCs, APFC, lighting). Key features:

• Incoming circuit breaker: ACB (Air Circuit Breaker) typically 800A–5000A
• Outgoing breakers: MCCBs feeding MCCs and other distribution panels
• Bus bar rating: matches incoming — copper/aluminium, fully insulated
• Energy meter, multi-function meter, voltmeter, ammeter on incoming
• Form: Form-2b, Form-3b, or Form-4b separation as per IEC 61439
• Short-circuit withstand rating: typically 50 kA or 65 kA for 1 second

2. MCC — Motor Control Center

The MCC is the heart of motor control in any factory. It contains starters — DOL, Star-Delta, Soft Starter, or VFD — for each motor in a plant area. A medium factory typically has 5–15 motor feeders per MCC.

• Incoming from PCC: usually 250A–1600A MCCB
• Each feeder: MCCB or MPCB + contactor + thermal overload relay
• For larger motors (above 7.5 kW), star-delta or soft starter
• VFD feeders if speed control needed
• Drawer-type or fixed compartment construction
• Communication: Modbus RTU or Profibus to PLC for status & control

3. VFD Panel

A VFD panel houses Variable Frequency Drives for one or more motors. It can be standalone (single drive) or part of a larger MCC. Critical design features:

• Input contactor & MCCB
• Line reactor or input choke (recommended above 22 kW)
• VFD itself — Siemens SINAMICS, ABB ACS, Delta MS300, Schneider Altivar, Yaskawa, Fuji
• Output dV/dt or sine wave filter (for long motor cables)
• Braking resistor (for fast-decelerating loads)
• Forced ventilation with filtered air — VFDs dissipate 2–5% of rated power as heat
• Bypass arrangement (DOL fallback) for mission-critical applications

4. PLC Panel / Automation Panel

Houses the PLC, I/O modules, 24V DC SMPS, terminal blocks, interposing relays, and communication switches. Often integrated with an HMI on the door.

• PLC CPU + power supply + I/O modules + comm cards
• 24V DC SMPS — redundant for critical applications
• Interposing relays for high-current outputs
• Ethernet switch for HMI and SCADA connectivity
• HMI mounted on the door (7"–15" typical)
• Separate compartment for power (230V AC) and control (24V DC) sections to avoid noise

5. APFC Panel — Automatic Power Factor Correction

Connects capacitor banks to maintain plant power factor (PF) at 0.99+ — avoiding penalty from the electricity board (DGVCL, MGVCL, PGVCL, etc.) and reducing kVA demand charges.

• Capacitor steps: 10 kVAr to 100 kVAr each, typically 8–16 steps
• APFC relay (controller): EPCOS, Selec, ABB, Schneider
• Detuned reactors for harmonic-rich loads (factories with many VFDs)
• Contactors or thyristor switches (TSC) for fast switching
• Heavy-duty capacitors — gas-filled or dry, IEC 60831 rated
• Ventilation: capacitors generate heat, must be cooled

6. AMF Panel — Auto Mains Failure

Detects mains power failure and automatically starts the diesel generator, transfers load, and brings mains back when restored. Standard for any factory with a backup DG set.

• AMF controller: Deepsea DSE, ComAp, Lovato, ABB
• ATS (Automatic Transfer Switch) — motorised changeover
• Mains and DG breakers — mechanically & electrically interlocked
• DG start/stop relay logic, fuel low / battery low alarms
• Load shed contacts for non-critical loads

7. Lighting Distribution Board (LDB)

Distributes 230V single-phase or 415V three-phase power to lighting circuits. Smaller and simpler than MCC/PCC.

• MCB (10A–63A) per circuit
• RCCB / RCBO for safety (residual current protection)
• Timer or photocell-based switching (for outdoor lighting)
• Surge protection device (SPD) on incoming

8. Synchronisation Panel

For factories running multiple DG sets in parallel, or running DG synchronised with grid. Used in larger plants, hospitals, hotels, data centres.

• Synchronising relay + check synchronisation
• Speed governor control
• Automatic voltage regulator (AVR) control
• Load sharing across DGs

9. Quick Reference Table

10. What to Ask Your Panel Manufacturer

• Is the panel CPRI / ERDA tested for the rated short-circuit current?
• Which IEC standard does it comply with (IEC 61439-1/2)?
• What is the IP rating — IP42, IP54, or IP65 for outdoor?
• Form of internal separation (Form-1, 2, 3, or 4)?
• Are components from approved makes (Siemens, ABB, Schneider, L&T, C&S)?
• Is there a name plate showing rated voltage, current, Icw, Icu, IP?
• Are wiring colour codes per IS standards?
• What is the warranty — usually 12 months on workmanship?
• Is GA drawing, single-line diagram, and as-built drawing provided?