A given automatic transfer switch (ATS) may have several SCCR levels that are marked by the manufacturer on the equipment, and the exterior marking must reflect the selected level.

A given automatic transfer switch (ATS) may have several SCCR levels that are marked by the manufacturer on the equipment, and the exterior marking must reflect the selected level.

• A. True
• B. False
• C. Only for some installations
• D. Not required

Answer: (A)

When an automatic transfer switch offers multiple SCCR levels, the level you actually configure for a given installation is the one that matters for safety and coordination with upstream protection. The exterior marking must reflect that selected level so anyone installing or servicing the ATS can see exactly what short-circuit current it is rated to interrupt in that configuration. This avoids hidden mismatches between the system’s fault current and the device’s capability, supports proper protection coordination, and aligns with safety and labeling standards. Since the device may be configured to a specific SCCR, the marking should match that configuration at the exterior of the equipment. Hence, the statement is true. It’s not a matter of optional labeling or only applying to some installations—the marking must indicate the chosen SCCR whenever multiple levels are available.

When an automatic transfer switch offers multiple SCCR levels, the level you actually configure for a given installation is the one that matters for safety and coordination with upstream protection. The exterior marking must reflect that selected level so anyone installing or servicing the ATS can see exactly what short-circuit current it is rated to interrupt in that configuration. This avoids hidden mismatches between the system’s fault current and the device’s capability, supports proper protection coordination, and aligns with safety and labeling standards. Since the device may be configured to a specific SCCR, the marking should match that configuration at the exterior of the equipment. Hence, the statement is true. It’s not a matter of optional labeling or only applying to some installations—the marking must indicate the chosen SCCR whenever multiple levels are available.