Frequently Asked Qestions
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We want to be responsive to as many electrical fitting issues as possible. If there is any industry topic that you would like to see covered here, please send an email to AMFICO's marketing department marketing@americanfittingscorp.com.
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American Fittings Corporation is committed to the growth and development of the electrical industry. This area of our website is designed to help the electrical professional stay on top of current application and regulatory issues.
This area will be updated on a regular basis to provide tips for installation and usage of AMFICO products, as well as regulatory information from the Federal Government regarding the industry.
Grounding Bushings and their use
Grounding Bushings are intended for use with threaded rigid or intermediate metal conduit and an aluminum or copper lug for connecting a bonding or grounding wire. Never exceed or reduce the wire capacity specified on the lug or carton label. Bushings have insulated throat for abrasion protection when pulling wire, black or brown colored insulator rated for 150 degrees C, other colors rated 105 degrees C. The set screw in the Bushing assures bonding to the conduit.
When installing a Grounding Bushing to rigid or intermediate metal conduit, a locknut must be used on the inside and outside of box or enclosure. Assemble the Bushing hand tight and with wrench, or similar tool, tighten additional 1/4 turn; tighten set screw and assemble bonding or grounding wire. Note: the Bushing lug may be rotated to prevent interference with box or enclosure. Tighten screw securely after repositioning lug. Grounding Bushings provide electrical continuity required by the NEC for service entrance and circuits rated over 250 volts.
Why do some fittings require taping to be Underwriters Laboratories (UL) listed?
Raceway systems such as EMT and rigid conduit are permitted by most codes to be embedded in concrete. The solid exterior of these conduits eliminates the possibility of concrete entrance, however, the termination with the connector or coupling can be susceptible to concrete entering the raceway. Included in the UL testing procedure is assembly of the connector or coupling to the conduit, pouring of Portland-type concrete over test samples enclosed in form box, vibrating the concrete surface, and after concrete drying examine the connections for concrete entrance. Although compression style connectors and couplings pass these tests in all trade sizes because of gland ring design, set screw type may have difficulty conforming to UL requirements. When the set screw is tightened onto the conduit, the fitting material will "yield", or stretch, enough to create an opening at the conduit/fitting connection. Set screw fittings in the smaller (1/2", 3/4", and 1") trade sizes are less likely to stretch to the point that would permit entrance of concrete. However, 1-1/4" and larger size fittings will yield enough so that concrete can enter the raceway. UL will accept product carton marking that specify "Concrete-Tight When Taped" on fittings that cannot pass the fore- mentioned testing since the tape prevents entrance of concrete into the raceway. The taped joint must completely encircle the conduit/fitting connection
Hints on selecting the right conduit and cable fittings
Conduit and cable fittings are available in a variety of materials such as malleable iron, steel and die-cast zinc. Material selection is usually a personal choice based on past experience or specification requirements. Regardless of the material, all fittings must pass the same mechanical and electrical performance tests at independent testing laboratories such as Underwriters Laboratories (UL) or Canadian Standards Association (CSA).
Many fitting manufacturers are developing new products or redesigning existing fittings that can be considered "labor savers." These products will reduce the electrical contractor's installation time. When purchasing fittings, contractors should expect consistent quality, performance and ease of use.
UL and CSA monitor electrical codes and revise their listing or certification specifications to comply with revisions or additions. Products that have been tested and listed by an independent testing facility will perform the same function as domestic manufactured products.
Listed or certified foreign-made fittings must pass the same functional requirements as nationally produced fittings. UL and CSA provide follow-up inspection services for listed or certified fittings in many other countries such as India and China.
UL and CSA require that all application information and special instructions be printed on the smallest carton label. Types of conduit and/or cable will be noted on the label.
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