Important News!
The April 2005 edition of NEC Digest contains
a ground-breaking article entitled “Handholes and Underground
Electrical Enclosures”. This educational article presents
a thorough understanding of issues relating to the performance
of underground enclosures and explains the importance of safety
standards, including the 2005 NEC, ANSI/SCTE. 77-2002, and
UL listing.
2005 NEC and Underground
Enclosures
The 2005 edition of the National Electric
Code addresses underground enclosures for the first time in
its history. The NEC now states in article 314.30 that enclosures “shall
be designed and installed to withstand all loads likely to
be imposed,” 1 and addresses issues related to enclosure
size, wiring entries, enclosures without bottoms, and bonding
requirements for covers.
The Code references the ANSI/SCTE
77-2002 “Specification
for Underground Enclosure Integrity” National Standard
2, which outlines various tests that enclosures must pass to
meet the standard. ANSI/SCTE 77-2002 also provides load charts
with Tier ratings to help end users determine the appropriate
enclosure to select depending on the loadings expected in the
application.
QUAZITE® Enclosures UL Listed to ANSI
Standard
All QUAZITE® enclosures
meet or exceed the test provisions of ANSI/SCTE 77-2002 and
most enclosures sized 30” x 48” and smaller are
even UL Listed to the ANSI National Standard as referenced
in the 2005 NEC. This means that QUAZITE® enclosures have
undergone rigorous physical, environmental and internal equipment
protection tests and have been found by UL, a neutral third
party, to meet the test requirements of the ANSI National Standard.
No
one wants to be responsible for an accidental electrocution
from a collapsed enclosure or energized cover. By using the
2005 NEC, ANSI/SCTE 77-2002 and UL Listing requirements in
the enclosure selection process, end-users will help ensure
long service life, increase safety and reduce potential liability
associated with failed underground enclosures.
UL Listing
Card
Testing Requirements for
ANSI/SCTE 77-2002
Underground enclosures must successfully pass
numerous material and product performance tests before they
can meet ANSI/SCTE 77-2002. These tests include:
• Three Position Load Testing to Simulate
Actual Application
• UV Degradation per ASTM G-53
• Fire Resistance per RUS7CFR 1755.910 and WUC 3.6 Section 5.2.7
• Chemical Resistance per ASTM D-543
• Water Absorption per ASTM D-570
• Load and Deflection Requirements per SCTE Coaxial Practice, Section
5
• Impact Resistance per ASTM D-2444
• Accelerated Service per ASTM D-756
NOTE: Quazite
recommends testing by third party organizations such as UL
to verify that enclosures meet all test provisions of ANSI/SCTE
77-2002.
- National Fire Protection Agency, 2005
National Electric Code. Thomson Delmar Learning, Sept. 24,
2004.
- A copy of the standard may be purchased
from ANSI.
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