On the nameplate of a Siemens SIMOPRIME medium-voltage switchgear panel, you'll find the designation "IAC A FLR 40 kA 1 s." Many specifications copy it verbatim — but do you know what it actually means? This classification, defined under IEC 62271-200, describes what happens to personnel if an internal arc fault releases the full energy of the failure.

What Does IAC A FLR 40 kA 1 s Mean?

IAC (Internal Arc Classification) is the IEC 62271-200 classification that certifies, through type testing, that the switchgear enclosure protects personnel in the event of an internal arc fault. The SIMOPRIME panel achieves an IAC A FLR classification rated up to 40 kA. Here's how to decode it:

To pass the test, five criteria must be met simultaneously:

Specification takeaway. Require the full classification — accessibility, sides, current, and duration — and verify that the tested current covers your busbar's actual short-circuit rating. An "arc-resistant" panel without these five data points is a marketing claim, not a classification.

LSC 2B and Partition Class PM: Servicing Without De-Energizing the Bus

LSC (Loss of Service Continuity) defines, under IEC 62271-200, which compartments of the switchgear can remain energized when an accessible compartment is opened. The SIMOPRIME panel holds the most demanding category, LSC 2B: the circuit breaker compartment can be opened while the busbar, cable compartment, and adjacent functional units remain in service.

Partition class PM (Partition Metallic) complements this classification: the barriers between the open compartment and energized parts are metallic and grounded, not insulated. For a process plant, an Oil & Gas operation, or a utility, this combination translates directly into breaker maintenance without de-energizing the substation.

SIMOPRIME Switchgear: Nameplate Data

Manufactured in Colombia Under the Siemens Grid Plus Program

Industrias Ectricol S.A.S., a Siemens Technology Partner under the Grid Plus program, manufactures the SIMOPRIME switchgear at its plant in Funza, Cundinamarca, Colombia, and is the only Colombian panel builder authorized by Siemens to manufacture this solution, with routine tests performed prior to every shipment.

Applications by Industry

The IAC A FLR / LSC 2B combination is especially critical where personnel safety and system availability cannot be compromised: Oil & Gas substations, Mining operations, and Utilities and Renewable Energy projects that require breaker maintenance without scheduled service outages.

Applicable Standards

IEC 62271-200 is the international reference standard for metal-enclosed switchgear and controlgear in medium voltage. In markets where NEC/NFPA 70, IEEE, and ANSI/NEMA frameworks apply, project engineers should confirm equivalent short-circuit and arc-resistance criteria with the specifying authority. Refer to the official IEC 62271-200 standard.

Frequently Asked Questions