Know the Mark meanings of A Building & House Wire
AmpacityMEANING - The current in amperes a conductor can carry constantly below the conditions of use with no surpassing its temperature ranking
Force required to generate current stream, commonly called "electromotive force" (emf). Voltage essentially must be stated as being a slope between two ends or targets; eg, phase-to-ground represents the voltage gradient among an ungrounded conductor and a grounded target.
- All building wire & cable must be flame retardant as specified in the National Electrical Code. UL Standards contain flame tests to ensure the products comply with the NEC requirement.
- VW-1 - Where a higher level of fire retardant is preferred, over that required for all wire & cable, this Vertical Wire flame test can be enforced. This is an alternative fire ranking, and items complying with the test may have the extra marking "VW-1."
- VERTICAL TRAY - This is also a not required fire ranking, and products meeting the test requirements are considered good for installation in cable racks and may be marked "for CT use" or similar phrasing. The 1999 NEC would authorize solo conductor sizes 1/0 AWG and greater to get installed in cable trays.
The temperature ranking of a conductor is a highest temperature level, at any place along its span, which the conductor can hold up against over an extended duration of time with no considerable downgrading.