Search results
Results From The WOW.Com Content Network
Certified and labelled for use in areas with specific hazardous conditions: for indoor and outdoor use in locations classified as Class II, Groups E, F, or G as defined in NFPA standards such as the NEC. 10: MSHA. Meets the requirements of the Mine Safety and Health Administration, 30 CFR Part 18 (1978). 11: General-purpose.
The NEC Zone system was created to harmonize with IEC classification system, and therefore reduce the complexity of management. Canada has a similar system with CSA Group standard C22.1, the Canadian Electrical Code , which defines area classification and installation principles.
Rising damp is the effect of water rising from the ground into property. [3] The damp proof course may be horizontal or vertical. [4] A DPC layer is usually laid below all masonry walls, regardless if the wall is a load bearing wall or a partition wall. A damp-proof membrane (DPM) is a membrane material
Damp-proofing rods are available with BBA approval. The rods are placed into holes drilled in the mortar course and the active ingredients diffuse along the mortar line before curing to form a damp-proof course. [53] Damp-proofing rods are usually supplied in 180mm (7") lengths suitable for inserting into a 9-inch thick wall.
A great deal of THWN wire is actually dual-rated, and meets THHN the specification as well, so may be used in wet environments up to 75°C or dry environments up to 90°C. An extended specification, THWN-2 permits use in wet locations and conductor temperatures up to 90°C simultaneously. [18]
According to the NEC, the purpose of connecting an electrical system to the physical ground (earth) is to limit the voltage imposed by lightning events and contact with higher voltage lines. In the past, water supply pipes were used as grounding electrodes, but due to the increased use of plastic pipes, which are poor conductors, the use of a ...
The National Electrical Safety Code (NESC) or ANSI Standard C2 is a United States standard of the safe installation, operation, and maintenance of electric power and communication utility systems including power substations, power and communication overhead lines, and power and communication underground lines.
The NEC refers to this type of ground as a "Concrete Encased Electrode" (CEE) instead of using the name Ufer ground. Over the years, the term "Ufer ground" has become synonymous with the use of any type of concrete enclosed grounding conductor, whether it conforms to Ufer's original grounding scheme or not.