The Allied Intermediate Metal Conduit (IMC) raceway system is an optomized system matching product to requirement - it was designed specifically to protect insulated electrical condutors and cables, eliminating the need for a heavier wall product. Allied IMC is lighter in weight and has a larger interior diameter than galvanized rigid conduit (GRC) and is recognized in the NEC.
Allied IMC has been subjected to more extensive testing than any other conduit product to validate its electrical and mechanical performance characteristics. It meets or exceeds the service requirements of modern electrical systems. And since its introduction, it has been successfully installed in commercial and industrial applications invoving millions of feet.
Where IMC is used
IMC is recognized by the NEC for the same uses as rigid conduit, including all hazardous locations. It can be installed above or below grade, in concrete or earth, and used in high-voltage installations (over 600 volts). IMC may be used under all atmosperic conditions, in all occupancies, and under the same conditions as rigid.
The NEC recognized IMC as an equipment grounding conductor and permits use of U.L. listed set-screw and compression no-thread fittings.
Features of Allied IMC
Allied IMC is manufactured from sheet steel, work hardened through the forming process to provide exceptional strength for its weight. (The steel used in Allied IMC meets the general requirements for carbon and high-strength low-alloy steel ASTM-A568.)
Allied IMC is protected from corrosion by a patented hot dip zinc Flo-Coat process which combines galvanizing and other special protective coating steps with the mill process. In addition, a specially formulated, highly corrosion-resistant lubricating coating is applied to the interior surfaces. (Both interior and exterior coatings meet U.L. 1242.) This coating, together with IMC’s larger interior diameter in all trade sizes, greatly reduces wire pulling effort.
Allied IMC is available in ten trade sizes from 1/2” thru 4”. Each length is identified at 2-1/2 ft. intervals with the letters IMC 1/4” high (and carries the U.L. label), and a coupling is supplied with each 10-ft. length. Further identification is provided by IMC color-coded end-cap thread protectors, as follows:
Even length sizes - Orange
1/2-inch sizes - Yellow
1/4-inch sizes - Green
IMC threads are full cut for tight-fitting connections. The standard threads accomodate all the threaded GRC couplings, junction boxes, outlet boxes, and other electrical fittings. The threads are galvanized for protection against corrosion.
IMC is easily cut and field threaded using standard tools. Bending can be done in the field or shop using a variety of IMC bending equipment.
How to Specify IMC
To specify IMC, or any other electrical conduit product, you can use the standard Construction Specifications Institute (CSI) format, Section 16. An additional reference to cite is the Underwriters’ Laboratory General Information card #DYBY.
本文转自：China Industry News