Fully drawout motor control centres for zero-downtime maintenance
A drawout MCC panel mounts every motor starter in a withdrawable module that plugs onto the vertical busbar through the rear and onto the outgoing cable terminals through a secondary connector. When a starter needs attention, the module is isolated, racked out and replaced with a spare in minutes while the busbar and every other motor stay live. Accu-Panels Energy manufactures Form 4b drawout MCCs to IEC 61439-2 on a CPRI type-tested platform, from 400 A to 6300 A busbar rating, at its Ahmedabad works for process industries in India and export markets.
Continuous-process plants — cement, steel, chemicals, pharma, paper, water treatment — cannot shut down a whole MCC to change one contactor. Drawout construction solves this: each functional unit sits in its own compartment with isolated (connected / test / isolated / withdrawn) positions, mechanical interlocks that prevent withdrawal under load, and shutters that cover the live busbar contacts when the module is removed. Accu-Panels drawout MCCs are engineered from your motor list with DOL, star-delta, soft-starter or VFD modules in standard module heights so spares are interchangeable.
- Form 4b internal separation: busbars, functional units and terminals in separate compartments
- Withdrawable modules with connected / test / isolated positions and padlockable interlocks
- Automatic safety shutters over vertical busbar contacts
- Silver-plated main and module contacts for low temperature rise
- Standard module heights for interchangeable spares across the plant
- Intelligent motor relays with Modbus / Profibus communication on request (see IMCC)
- Front access only, back-to-wall or double-front layouts
- IEC 61439-1/2 assembly; switchgear per IEC 60947-2/4-1; CPRI type-tested design
- 415 V AC, 3-phase, 50 Hz; control 230 V AC / 110 V AC / 24 V DC
- Main busbar 400 A to 6300 A; vertical droppers 400 A to 1600 A
- Short-time withstand 50 kA / 65 kA / 80 kA for 1 s
- Modules: DOL up to 45 kW, star-delta up to 250 kW, soft-starter and VFD modules, feeder modules up to 630 A
- Degree of protection IP42 / IP54 (IEC 60529)
- Enclosure 2.0 mm CRCA frame, 1.6 mm doors, 7-tank pre-treatment, powder coated
Cement and steel plants, chemical and petrochemical units, pharmaceutical and API manufacturing, pulp and paper, water and wastewater treatment plants, power plant auxiliaries and any process line where an unplanned MCC shutdown costs more than the drawout premium. Fed from an upstream PCC panel; compare with our fixed MCC panels.
Fixed vs drawout MCC: cost and uptime
A drawout MCC typically costs 20–35 % more than a fixed MCC of the same feeder list because of the module hardware, shutters and silver-plated contacts. It pays back on the first avoided shutdown: a starter change that takes a two-hour outage on a fixed MCC takes ten minutes with no outage on a drawout MCC. Accu-Panels offers both on the same type-tested platform, and hybrid designs where only critical drives are drawout.
Frequently asked questions
What does Form 4b mean?
Under IEC 61439-2, Form 4b separates the busbars from functional units, functional units from each other, and the outgoing terminals of each unit from the others — the highest standard form and the natural fit for drawout construction.
Can modules be interchanged?
Yes, within the same module height and rating. We standardise module sizes across a project so one spare module covers many feeders.
Can a module be tested without running the motor?
Yes. In the test position the control circuit is connected while the power contacts are isolated, so the starter logic can be checked safely.
Do you retrofit drawout modules into existing MCCs?
We can add drawout sections to compatible Accu-Panels MCCs and supply replacement modules; for other makes we review drawings case by case.
What is the lead time?
6 to 10 weeks after drawing approval, depending on module count and switchgear delivery.
Send your motor list to our engineering team for a drawout MCC proposal.
