Before specifying underground enclosures, one of the first questions to ask yourself is whether or not the enclosure will be used in deliberate traffic applications or non-deliberate traffic applications.
ANSI-SCTE 77 is a performance specification for non-deliberate traffic applications with specific tier load ratings listed. Before 2002 there had never been a true, non-deliberate traffic standard. Today, the ANSI-SCTE committee meets every three to five years to consider possible updates to the standard. The standard was last updated in 2013.
Three Position Structural Testing
The ANSI-SCTE standard strictly adheres to three position structural testing of both the enclosure and cover to simulate typical, non-deliberate vehicular loadings, impact resistance, chemical resistance, UV degradation, water absorption, flammability, internal equipment protection, coefficient of friction, torque value of fastening devices.
Three position testing is required to determine how a product will perform in actual use. In order to qualify a product's performance, test loading should be performed at the lateral center of the longest sidewall, at the vertical center of the longest sidewall, and at the vertical position in the center of the cover.
Proper ANSI-SCTE standards include the following load readings:
- Tier 5, sidewalk applications, light duty truck up to class 3
- Tier 8, sidewalk applications, light duty truck up the class 3
- Tier 15, driveway, parking, lot and off roadway applications, medium duty truck up the class 7
- Tier 22, driveway, parking lot, and off roadway applications, heavy duty truck up to class 8
ANSI-SCTE testing is essential for all underground enclosures. How can you tell if your enclosure has been tier tested? Rely on testing conducted by a third party organizations, such as Underwriter's Laboratory or ETL. Request a letter from the manufacturer stating that the enclosure meets the published ANSI-SCTE testing criteria.
If you have questions about ANSI-SCTE or any other applications for enclosures, please call your Hubbell representative. We'd be happy to work with you in specifying your underground enclosure applications.