MCC Panels

Motor Control Center (MCC) — ATEX / IECEx Certification

ATEX / IECEx Certification compliance requirements, testing procedures, and design considerations for Motor Control Center (MCC) assemblies.

Motor Control Center (MCC) — ATEX / IECEx Certification

Overview

ATEX / IECEx certification compliance for a Motor Control Center (MCC) is a specialized hazardous-area engineering task that combines low-voltage assembly design with explosive-atmosphere conformity requirements. In most projects, the MCC itself is installed in a safe area or a non-hazardous electrical room and then serves Ex-rated process equipment located in Zone 1, Zone 2, or dust Zone 21/22 areas. The compliance path therefore starts with hazardous area classification, equipment selection, and a clear determination of whether the assembly is a standard low-voltage MCC, a pressurized/purged system, or an enclosure with associated protective interfaces for field equipment. The electrical assembly portion of the design must be verified to IEC 61439-1 and IEC 61439-2, with additional application-dependent references to IEC 61439-3 for distribution boards and IEC 61439-6 for busbar trunking interfaces where the MCC is fed from or connected to compact distribution systems. For hazardous atmospheres, the relevant framework is IEC 60079 and the ATEX Directive 2014/34/EU, with IECEx certification following the international scheme. Depending on the protection concept, the design may need to address IEC 60079-0 for general requirements, IEC 60079-1 for flameproof enclosures, IEC 60079-2 for pressurization, IEC 60079-7 for increased safety, IEC 60079-11 for intrinsic safety, and IEC 60079-31 for dust ignition protection by enclosure. If the project requires internal arc resilience, IEC 61641 is often specified as a supplementary test reference. Modern MCC lineups may include ACB incomers up to 6300 A, MCCB feeders, contactor starters, overload relays, motor protection circuit breakers, VFDs, soft starters, protection relays, PLCs, and communication gateways. In ATEX / IECEx projects, each device must be assessed for thermal impact, fault behavior, and compatibility with the declared ambient temperature and the intended temperature class. VFDs and soft starters are particularly sensitive because they generate heat and can influence enclosure temperature rise, cable derating, and ventilation strategy. Where Ex i instrumentation is integrated, galvanic isolators, Zener barriers, and dedicated segregated wiring routes are required to maintain the entity parameters and prevent accidental energy transfer into hazardous circuits. A compliant MCC design also depends on forms of separation and segregation inside the enclosure. Power feeders, control wiring, and intrinsically safe circuits must be physically separated using barriers, wire-ways, and clearly defined cable entry zones. Depending on the required operational robustness, forms of internal separation consistent with IEC 61439 may be implemented to limit fault propagation between functional units. If the MCC uses a purged enclosure, the pressurization arrangement must meet IEC 60079-2 requirements for purge duration, pressure supervision, alarms, interlocks, and loss-of-pressure shutdown logic. For dusty environments, enclosure sealing, dust ingress control, and surface temperature management become critical to maintaining certification validity. Verification is not limited to a single type test. The certification file typically includes design verification results for temperature rise, dielectric withstand, short-circuit withstand, clearances and creepage distances, IP degree, mechanical strength, protective circuit continuity, and terminal suitability. Short-circuit performance must be aligned with the available fault level at the installation point, with ratings expressed as Icw, Icc, or conditional short-circuit current as applicable. Routine tests, wiring checks, functional tests, and inspection of protective measures are required before shipment, and the technical dossier must include drawings, BOMs, certificates, nameplate data, risk assessments, and test records. For EPC contractors, plant owners, and panel builders, maintaining compliance is an ongoing process. Any change to enclosure type, ventilation, component brand, protection concept, or cable entry system can trigger re-verification and potentially re-certification. Patrion designs and manufactures MCC panels in Turkey with a documentation-led approach that supports ATEX / IECEx projects from concept review through FAT, commissioning support, and lifecycle change control.

Key Features

  • ATEX / IECEx Certification compliance pathway for Motor Control Center (MCC)
  • Design verification and testing requirements
  • Documentation and certification procedures
  • Component selection for standard compliance
  • Ongoing compliance maintenance and re-certification

Specifications

PropertyValue
Panel TypeMotor Control Center (MCC)
StandardATEX / IECEx Certification
ComplianceDesign verified
CertificationAvailable on request

Other Standards for Motor Control Center (MCC)

IEC 61439-2 (PSC)

Power switchgear and controlgear assemblies — main compliance standard

Marine Classification (DNV/Lloyd's/BV)

Type approval for marine and offshore installations

Arc Flash Protection (IEC 61641)

Internal arc classification and containment

Seismic Qualification (IEEE 693/IBC)

Earthquake resistance verification for critical facilities

UL 891 / CSA C22.2

North American switchboard safety standards

Other Panels Certified to ATEX / IECEx Certification

Variable Frequency Drive (VFD) Panel

Enclosed VFD assemblies with input protection, line reactors, EMC filters, output reactors, and bypass options.

PLC & Automation Control Panel

Process and machine control panels housing PLCs, I/O modules, relays, HMIs, and communication infrastructure.

Custom Engineered Panel

Bespoke panel assemblies for non-standard requirements — special ratings, unusual form factors, multi-function combinations.

Soft Starter Panel

Enclosed soft starter assemblies for reduced voltage motor starting with torque control, ramp-up/down profiles, and bypass contactor options.

Frequently Asked Questions

Only if the complete installation arrangement is compliant with the applicable hazardous-area rules and the MCC itself is not treated as an ignition source. In many projects, the preferred solution is to locate the MCC in a safe area and run protected circuits to the Zone 2 field devices. If the MCC is installed within or adjacent to the classified area, the enclosure, internal components, cable entries, temperature rise, and protection concept must be evaluated against IEC 60079 and the ATEX Directive 2014/34/EU. The final design may require flameproof, increased safety, or pressurized protection, depending on the risk assessment and zone classification.
The core low-voltage assembly standard is IEC 61439-1, with IEC 61439-2 typically used for MCC assemblies. If the MCC includes distribution sections or busbar interfaces, IEC 61439-3 or IEC 61439-6 may also apply. The hazardous-area framework is defined by IEC 60079, especially IEC 60079-0 and the relevant protection-specific parts such as IEC 60079-2, -7, -11, and -31. Where the project specifies internal arc testing, IEC 61641 is commonly referenced. The exact combination depends on the installation zone, protection concept, and whether dust or gas atmospheres are present.
VFDs and soft starters are allowed in many MCC designs, but their thermal output, harmonic behavior, and fault response must be included in the design verification. Under IEC 61439, the enclosure temperature rise and component derating must remain within limits, and for hazardous-area applications the devices must not compromise the declared protection concept. If the MCC also interfaces with Ex i circuits or installed field equipment, the wiring segregation, earthing, and cable entry arrangement must be carefully controlled. In practice, this often means dedicated ventilation, thermal zoning, and strict component selection based on certified operating conditions.
ATEX is the European legal framework for equipment intended for explosive atmospheres, while IECEx is an international certification scheme based on IEC standards. For an MCC, both routes rely heavily on IEC 60079 technical requirements, but ATEX includes conformity assessment obligations for the EU market and specific marking requirements. IECEx certification is often preferred for multinational projects because it is widely recognized outside Europe. Many suppliers prepare the MCC design so it can be assessed under both schemes, provided the enclosure, components, and documentation are aligned with the selected protection concept.
Testing typically includes IEC 61439 design verification evidence and routine production checks. These usually cover wiring continuity, insulation resistance, dielectric withstand, functional operation, verification of clearances and creepage, and inspection of protective bonding. For hazardous-area installations, additional review is required for enclosure temperature rise, IP protection, cable entry integrity, and the validity of the chosen Ex protection concept. If the MCC is pressurized, purge and pressure interlock tests are also necessary under IEC 60079-2. The final test pack should include certificates, nameplate data, drawings, and traceable inspection records.
Yes, but only with strict segregation and documentation. Intrinsically safe circuits must be separated from non-intrinsically safe wiring by physical barriers, dedicated ducting, and controlled cable routing, with entity parameters or loop parameters maintained throughout the system. IEC 60079-11 governs intrinsic safety, while the assembly design should also follow IEC 61439 segregation principles to prevent accidental energy transfer. In a practical MCC layout, Ex i barriers or galvanic isolators are mounted in dedicated control sections, away from high-power feeders, VFD outputs, and switching devices.
Re-certification or formal re-verification is typically required whenever the certified design changes in a way that affects ignition protection, thermal performance, or enclosure integrity. Common triggers include changing the enclosure type, modifying ventilation, replacing certified components with alternative brands, adding VFDs, altering cable entry systems, or relocating the MCC to a different zone or ambient condition. Even seemingly minor modifications can invalidate the original technical file if they affect the protection concept. For that reason, change control, spare part control, and as-built documentation are essential for lifecycle compliance.
The key ratings are the assembly short-time withstand current Icw, the prospective short-circuit current capability Icc, and, where applicable, conditional short-circuit current based on protective device coordination. These values must be matched to the fault level at the installation point and verified under IEC 61439. In an ATEX / IECEx context, short-circuit performance also matters because a high-energy fault can create excessive temperature rise, enclosure damage, or compromised Ex protection. MCC incomers and feeders commonly use ACBs or MCCBs with coordinated protection settings to ensure the assembly remains safe under fault conditions.

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