NEMA VE-1 has been revised and updated, with many significant changes that effect the way trays are tested, load rated and specified.
||NEMA VE-1 has been harmonized with the Canadian Standards Association (CSA) standard for cable tray (CSA C22.2 No. 126.1). This harmonization has been conducted by the joint efforts of CSA, NEMA, and others forming a CANENA Technical Harmonization Committee. The harmonized standard will be submitted to the Standards Council of Canada for approval as a National Standard of Canada, and to the American National Standards Institute (ANSI) for publication as an American National Standard.Commentary: CSA provides certification services for manufacturers who wish to use the CSA mark on their products to indicate conformity to CSA standards. With the harmonization of the document, the NEMA and CSA test standards are now the same.
||Due to the NEMA/CSA harmonization, a new cable tray test method option has been added to the document (Section 5.2.9). The new test is a “Loading to residual deflection” test, previously used in the CSA tray standard. The test involves removing the test weights after reaching a certain load, and measuring the amount of residual deflection in the tray.Commentary: The previous test in NEMA VE-1 was a destruction test. Either of the tests may be used. The destruction load test procedure has been modified for ladder type cable trays to require that the greatest rung spacing for the particular class of tray be used (Section 5.2.2).
||Due to the NEMA/CSA harmonization, the load/span class designations for cable trays have been expanded. The new Table 1 includes 3 meter and 6 meter spans, with load ratings corresponding to the previous CSA tray standard. Either the previous NEMA or CSA conventional load classes may be used. A note has been added (Section 4.8.1) to indicate that other load/span ratings are also acceptable.Commentary: The cable tray user/specifier may simply require any load/span combination to designate the load class of tray desired. Standard tray products are not limited to the conventional NEMA or CSA classifications.
||A rung load capacity test has been added to the standard (Section 5.4) as an option. The test prescribes a simple span concentrated load applied at the central 1” length of the rung.Commentary: This rung test provides a standardized method for tray manufacturers to rate the strength of their rungs. The rung is tested to destruction, and load rated with a safety factor of 1.5. Rung strength is often specified to prevent damage due to weak rungs in industrial (heavy duty) applications. The new document makes it very easy for specifiers to call out rung strength- “Individual rungs shall support a 200 lb. concentrated load when tested in accordance to NEMA VE-1, section 5.4”.
||Single-Rail cable trays have been added to the standard, in the definitions, dimensions, and testing sections. Single-rail cable trays may be center or side-supported, and single or multiple tier.Commentary: With the addition of single-rail cable trays to NEMA VE-1, this type of cable tray could be substituted for any conventional two siderail cable tray unless specified otherwise. A generic specification calling for 4” deep x 24” wide aluminum cable tray constructed and tested in accordance with NEMA VE-1 could be single or double rail construction.
||The wording has been changed in the Fittings paragraph (Section 4.5) to reflect that cable tray fittings may not meet the straight section strength requirements unless supported as shown in NEMA VE-2, or in accordance with the manufacturers’ instructions.Commentary: In order to assure that the cable tray fittings meet the load rating of the straight sections (which are tested), it is important that the installer realize that the fittings must be installed per NEMA VE-2 recommendations or as allowed by the tray manufacturer.
||The Product Marking requirements (Section 6.1) have been expanded to include the manufacturers name (or symbol), the words “ventilated” or “non-ventilated”, the load class or rated load/span, type of material, cross-sectional area for grounding (if applicable), and a warning statement. The manufacturer should also have readily available information on the maximum allowable between supports for each loading, material, and installation information.Commentary: This requirement increases the amount of information included with the cable tray, to aid in proper usage. This helps the installer and owner be aware of the maximum loads allowed in the installed trays, as well as electrical code and safety implications.
The document has been completely renumbered. Any specs, drawings, or standards referring to specific sections of the previous NEMA VE-1 should be updated to the new section numbers.
The document has been changed to utilize metric dimensions as standard (with English equivalents). 3000 mm and 6000 mm trays have been added as standard lengths.
With the addition of NEMA VE-2 (Metal Cable Tray Installation Guidelines) since the last version of VE-1, several references to VE-2 have been added.