Trirated Cable is a high temperature, flame retardant electrical cable designed for use in panel building. Trirated Cable is often referred to more generally as Panel Wire, T.R.S (tri-rated singles) or BS 6231 Cable.
Contents
Trirated Cable is so called because it meets the requirements of three different international standards: BS 6231, UL (or Underwriters Laboratories), and CSA (Canadian Standards Association). Combining three international standards in one product, makes Trirated Cable suitable for use in equipment required to meet both North American and European wiring regulations.
This single core cable is described as ‘high temperature cable’ because of the high temperatures to which it is subjected during the manufacturing process. According to the UL standard, the maximum operating temperature of Trirated Cable is 105 °C. This refers, however, to operating temperature for a specific length of time. The British Standard BS 6231 states that the cable should have a maximum operating temperature of 90 °C for continuous use.
Voltage rating is another area over which the different standards vary. UL and CSA give Trirated Cable a voltage rating of 600 V, whilst it is rated at 1000 V in the BS 6231 standard.
Construction
The typical construction of Trirated Cable is broken down as follows:
Uses
Trirated Cable is designed specifically for use in the switch, control, relay and instrumentation panels of power circuits and as internal connectors in rectifier equipment, motor starters and controllers.
BS 6231
BS 6231 is a British Standard last updated in 2006 by the BSI Group (a leading global provider of standards, management systems, business improvement and regulatory approval information). This standard specifies the performance and construction requirements of electrical cables that are single core, non-sheathed, PVC-insulated and of rated voltage 600/1000 V. Although many use the name BS 6231 when referring generally to tri-rated cable, this is an erroneous statement, not only because tri-rated cable is approved to two standards other than this one, but also because other electrical cables meet the requirements of this British Standard.
CSA
The Canadian Standards Association (CSA) is a non-profit membership-based association, which develops standards to protect public health and safety and to help preserve the environment in Canada and the global marketplace. Trirated cable is approved to CSA standard C22.2 Number 49, which specifies the requirements for flexible cords, elevator cables, and hoistway cables, rated to a maximum of 600 V.
UL
Underwriters Laboratories (UL) is an independent product safety certification organisation, which has been in operation since 1894. UL is the most famous Nationally Recognised Testing Laboratory (NRTL) in the United States and conducts certification testing of every electrical appliance. They use 70 different product categories and more than 30 Standards for Safety to evaluate wiring and cable products. UL62, the Standard for flexible cord, is the standard to which trirated cable is approved. It covers flexible cord constructed and listed for use in accordance with Article 400 of ANSI/NFPA 70, The American "National Electrical Code" (NEC). UL has a policy of cross-certification so that a product can be certified by UL using CSA standards, such products are certified C-UL.
2491B/6701B Panel Wire
Where Trirated Cable is required for installation in public areas a Low Smoke Zero Halogen (LS0H) equivalent must be used. 2491B/6701B Panel Wire is the LS0H equivalent of Trirated Cable, and is suitable for use in public areas. After the King’s Cross fire on 18 November 1987, where a number of the 31 fatalities were a result of toxic gas and smoke inhalation, it became mandatory to use LS0H sheathing on all London Underground cables. These LS0H Cables, which emit non-toxic levels of Halogen and low levels of smoke when exposed to fire, are now recommended for use in all highly populated enclosed public areas. 2491B/6701B Panel Wire is used in pipes or ducts and internal wiring of appliances, such as control equipment, in public buildings. LS0H properties are particularly important where smoke and toxic fumes may cause a threat to life.