MCC Panels

Custom Engineered Panel — IEC 61439-2 (PSC)

IEC 61439-2 (PSC) compliance requirements, testing procedures, and design considerations for Custom Engineered Panel assemblies.

Custom Engineered Panel — IEC 61439-2 (PSC)

Overview

Custom Engineered Panel assemblies built to IEC 61439-2 (PSC) are the core of low-voltage power distribution in industrial plants, commercial facilities, and infrastructure projects. As power switchgear and controlgear assemblies, they typically incorporate incoming air circuit breakers (ACBs), molded case circuit breakers (MCCBs), outgoing feeders, busbar systems, motor feeders, VFDs, soft starters, metering sections, and protection relays. Compliance is not achieved by component selection alone; it depends on verified assembly performance under the specific operating conditions declared by the manufacturer or system integrator. IEC 61439-2 applies to power switchgear and controlgear assemblies where the assembly is intended for professional use and is designed to distribute and control electrical energy. For Custom Engineered Panel projects, the compliance pathway begins with design verification in accordance with IEC 61439-1, which defines the general rules for assemblies, and IEC 61439-2, which covers power assemblies. Verification must address temperature-rise limits, dielectric properties, short-circuit withstand strength, protective circuit effectiveness, clearances and creepage distances, mechanical operation, and the degree of protection. Depending on the installation, the assembly may also need coordination with IEC 61439-3 for distribution boards, IEC 61439-6 for busbar trunking interfaces, IEC 60079 for explosive atmospheres, and IEC 61641 for arc fault testing where internal arcing mitigation is required. A compliant Custom Engineered Panel must be rated for the declared operational current, often ranging from 100 A to several thousand amperes, with busbar systems commonly engineered for 630 A, 1250 A, 3200 A, or higher depending on duty and enclosure size. Short-circuit ratings must be clearly established, such as 25 kA, 50 kA, 65 kA, or 100 kA for one second or as specified by the prospective fault level and protection coordination study. The selected protective devices, including ACBs, MCCBs, fuse-switch disconnectors, motor protection circuit breakers, overload relays, protection relays, and VFD incomers, must be coordinated with the assembly’s verified withstand and protective characteristics. Design considerations include busbar material and cross-section, segregation form, ventilation strategy, cable termination space, internal separation, and thermal management. Forms of separation, such as Form 2, Form 3, and Form 4, are often specified to improve safety, service continuity, and maintainability. For harsh industrial environments, enclosure ratings such as IP31, IP42, IP54, or higher may be required, while corrosion-resistant treatments and proper gland plate design support long-term reliability. Where arc fault performance is specified, the enclosure and internal arrangement must be evaluated for personnel protection and pressure relief behavior. Certification and documentation for IEC 61439-2 compliance typically include a verified design dossier, routine test records, nameplate data, wiring schedules, single-line diagrams, loss calculations, and evidence of component conformity to IEC 60947 series product standards. Routine verification on each manufactured panel generally includes inspection of wiring, dielectric testing, functional checks, protective circuit continuity, and mechanical operation. For EPC contractors, panel builders, and facility managers, maintaining compliance also means controlling approved components, tracking design revisions, and re-verifying after any modification to busbar layout, protective devices, enclosure dimensions, or thermal loading. In practice, IEC 61439-2 compliance gives confidence that the Custom Engineered Panel will operate safely, meet project specifications, and remain supportable throughout its service life.

Key Features

  • IEC 61439-2 (PSC) compliance pathway for Custom Engineered Panel
  • Design verification and testing requirements
  • Documentation and certification procedures
  • Component selection for standard compliance
  • Ongoing compliance maintenance and re-certification

Specifications

PropertyValue
Panel TypeCustom Engineered Panel
StandardIEC 61439-2 (PSC)
ComplianceDesign verified
CertificationAvailable on request

Other Standards for Custom Engineered Panel

ATEX / IECEx Certification

Explosive atmosphere compliance for hazardous areas

Marine Classification (DNV/Lloyd's/BV)

Type approval for marine and offshore installations

Seismic Qualification (IEEE 693/IBC)

Earthquake resistance verification for critical facilities

UL 891 / CSA C22.2

North American switchboard safety standards

IP Protection Ratings

Ingress protection classification (IP30–IP65+)

Arc Flash Protection (IEC 61641)

Internal arc classification and containment

EMC Compliance (IEC 61000)

Electromagnetic compatibility for sensitive environments

Other Panels Certified to IEC 61439-2 (PSC)

Main Distribution Board (MDB)

Primary power distribution from transformer to sub-circuits. Rated up to 6300A. Houses main incoming breaker, bus-section, and outgoing feeders.

Power Control Center (PCC)

High-capacity power distribution for industrial facilities. Controls and distributes incoming power to MCC, APFC, and downstream loads.

Motor Control Center (MCC)

Centralized motor control with starters, contactors, overloads, and VFDs in standardized withdrawable/fixed functional units.

Power Factor Correction Panel (APFC)

Automatic capacitor switching for reactive power compensation. Thyristor or contactor-switched, detuned or standard configurations.

Automatic Transfer Switch (ATS) Panel

Automatic changeover between mains and generator/UPS. Open or closed transition, with or without bypass.

Variable Frequency Drive (VFD) Panel

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

Generator Control Panel

Genset start/stop sequencing, synchronization, load sharing, and paralleling controls.

Metering & Monitoring Panel

Energy metering, power quality analysis, and multi-circuit monitoring with communication gateways.

PLC & Automation Control Panel

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

Soft Starter Panel

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

Harmonic Filter Panel

Active or passive harmonic filtering to mitigate THD from non-linear loads. Tuned LC filters, active filters, or hybrid configurations.

DC Distribution Panel

DC power distribution for battery systems, solar installations, telecom, and UPS applications. MCCB/fuse-based DC protection.

Capacitor Bank Panel

Fixed or automatic capacitor bank assemblies for bulk reactive power compensation in industrial and utility applications.

Frequently Asked Questions

IEC 61439-2 compliance means the custom engineered panel is a power switchgear and controlgear assembly whose design has been verified for its declared ratings and application. PSC refers to power switchgear and controlgear assemblies, typically used for incoming and outgoing power distribution with ACBs, MCCBs, busbars, and feeder sections. Compliance is based on the general requirements of IEC 61439-1 plus the specific requirements of IEC 61439-2. It covers temperature rise, dielectric strength, short-circuit withstand, clearances, creepage, and protective circuit integrity. A compliant assembly must also be supported by design verification evidence and routine verification records for every manufactured unit.
IEC 61439-2 relies on design verification and routine verification rather than a single universal type-test certificate. Design verification can be achieved by test, comparison with a reference design, assessment, or calculation depending on the characteristic being verified. Typical checks include temperature-rise verification, short-circuit withstand, dielectric properties, clearances and creepage distances, protective circuit continuity, and mechanical operation. Routine verification on each panel generally includes inspection, wiring checks, functional tests, and dielectric withstand testing where applicable. For arc-related requirements, IEC 61641 may be specified in addition to IEC 61439-2. Component product compliance is also expected, usually to IEC 60947 for breakers, contactors, starters, and control devices.
Yes. Air circuit breakers and molded case circuit breakers are standard devices in IEC 61439-2 compliant assemblies, provided their ratings and coordination fit the verified design of the panel. The assembly must be evaluated for incoming current, fault level, thermal dissipation, and busbar withstand. For example, an ACB incomer may be used at 1600 A, 2500 A, or higher, while MCCB feeders can serve outgoing circuits with appropriate breaking capacity and selectivity. The breakers themselves should comply with IEC 60947-2, and their settings must be coordinated with the assembly’s short-circuit rating and protective circuit design. The panel manufacturer remains responsible for overall assembly compliance, not the device supplier alone.
A complete compliance file should include the electrical design basis, single-line diagrams, general arrangement drawings, wiring schematics, bill of materials, component datasheets, design verification evidence, routine test reports, and the assembly nameplate data. It should also include declared values for rated voltage, rated current, frequency, short-circuit withstand rating, form of separation, IP rating, and any special environmental or arc-fault requirements. If the panel uses VFDs, soft starters, or protection relays, the documentation should show heat dissipation calculations and control power arrangements. For EPC and facility handover, this dossier is essential for traceability, maintenance, and future modifications without losing compliance.
Short-circuit rating is verified by proving that the assembly can withstand the prospective fault current for the declared duration without unacceptable damage. Under IEC 61439-2, this may be demonstrated by test on a representative design, by comparison with a verified reference arrangement, or by calculation where permitted. The verification must consider busbar strength, support spacing, enclosure integrity, protective device let-through energy, and protective circuit continuity. Common rated values include 25 kA, 50 kA, 65 kA, and 100 kA for 1 second, but the actual rating must match the project fault study. Breakers to IEC 60947-2 and coordinated settings are critical to achieving selective and safe operation.
IEC 61439-2 panels often use Forms 1, 2, 3, or 4 to define internal separation between busbars, functional units, and terminal compartments. Form 1 provides minimal separation, while Form 4 offers the highest degree of compartmentalization, supporting better maintenance and service continuity. The exact form selected depends on project requirements for safety, uptime, and accessibility. In practice, forms of separation influence cable routing, heat dissipation, fault containment, and maintenance procedures. A custom engineered panel with VFDs, PLCs, or critical feeders may require higher separation to improve operational continuity and reduce the risk of fault propagation.
Yes, if the custom engineered panel is a power switchgear and controlgear assembly distributing power to drives or motor loads. VFDs and soft starters are commonly integrated into IEC 61439-2 assemblies, but their heat output, harmonic effects, ventilation needs, and cable termination requirements must be included in the design verification. The associated power devices generally comply with IEC 60947 or relevant drive product standards, while the assembly itself must meet IEC 61439-2. For larger drive panels, thermal management and segregation are especially important, and the manufacturer may need to verify temperature rise under worst-case loading conditions. This is common in pump stations, HVAC plants, conveyors, and process lines.
Re-certification or design re-verification is required whenever a modification could affect the verified characteristics of the assembly. This includes changes to busbar size, breaker type, enclosure dimensions, cooling arrangement, internal separation, fault rating, cable entry, or protective circuit design. Even replacing a feeder with a different frame size MCCB or adding VFDs can alter thermal behavior and short-circuit performance. Under IEC 61439-1 and IEC 61439-2, the manufacturer must ensure the modified assembly still conforms to the declared ratings. For critical installations, updated routine tests and revised documentation should be issued before the panel is returned to service.

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