Eric Cerasale – Ericc@bptfittings.com – NESCO West Canada, NESCO East Canada
Larry Beach – Larryb@bptfittings.com – Alaska, Hawaii, Washington, Oregon, California, Idaho, Nevada, Montana, Wyoming, Utah, Colorado, Arizona, New Mexico, Illinois, Wisconsin, Minnesota, North Dakota, South Dakota, Nebraska, Iowa, Kansas
Wayne Beach – Wayneb@bptfittings.com – New York, New Jersey, Eastern Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Alabama, Florida, Louisiana, Oklahoma, Texas, Maine, Massachusetts, New Hampshire, Vermont, Rhode Island, Upstate NY, Western PA, Kentucky, West Virginia, Tennessee, Indiana, Ohio, Michigan
There are two armored Health Care Facility (HFC) cables recognized by Underwriters Laboratories: Type AC and Type MCI-A available in Steel or Aluminum interlocked armor.
Please reference our web site at www.bptfittings.com for specific product specifications. Keep in mind that while many of our Whipper-Snap® and Locknut styles connectors are suitable for MCI-A cable some are not.
When a green identification is required or specified, Bridgeport’s type 570-GI can be used to provide confirmation that the right cable has been terminated.
Bridgeport’s connectors are UL Listed under UL file number E-20534. The listing is proof of the products performance as an effective ground-fault current path, and can be confirmed via the (UL) website www.UL.com.
2011 NEC, Article 250.52(B) (1) states “(B) Electrodes Not Permitted for Grounding – (1) Metal underground gas piping system”. Gas piping by itself cannot be used as Ground Electrode Conductors. However, NEC Article 250.104, (B) Other Metal Piping – “The equipment grounding conductor for the circuit that is likely to energize the piping systems shall be permitted to serve as the bonding means.” Gas piping may be bonded only if it’s likely to be possibly energized by the equipment it is connected to. Most of the time, the piping will be bonded to the system automatically due to its metal fittings.
However, in the case of nonmetallic or flexible gas piping, a bonding jumper may need to be provided to complete the bonding path around the nonmetallic or flexible sections. There is an important difference worth noting. Grounding is not the same as Bonding. They are considered separate requirements by the NEC. Gas piping cannot be used for grounding, but it can be bonded if necessary. Flexible gas pipe system manufacturers will specify the method and system of bonding. In most cases, the clamp is placed on the metal hex fitting rather than over the flexible metal or nonmetallic tube.
As an example, the following is an excerpt from Gastite’s® CSST Installation Guide:
“The piping is permanently and directly connected to the electrical service equipment enclosure, the grounded conductor at the electrical service, the grounding electrode conductor (where of sufficient size) or to one or more of the grounding electrodes used. A single bond shall be made at or near the service entrance of the structure or the gas meter of each individual housing unit within a multi-family structure. The bonding conductor shall be 6 AWG copper wire. Bonding jumpers shall be attached in an approved manner in accordance with NEC-2005 Article 250.70 and the point of attachment for the bonding jumper shall be accessible. Bonding/grounding clamps listed to UL 467 comply with this requirement. This bond is in addition to any other bonding requirements as specified by local codes.”
Bridgeport’s ground clamps are not UL Listed individually to be used in a gas pipe bonding application – only to the basic standalone UL specification (UL 467).
In 2002, UL received field complaints that listed EMT compression split ring type rain-tight fittings were permitting the entrance of water into the conduit system. After checking the validity of these claims, UL made the decision to de-list ALL fitting manufacturers’ compression type raintight connectors and couplings.
A revised test method was employed by UL to represent actual field applications and conditions. Bridgeport was the first to develop and release an updated version of connector that met this revised requirement. Other fitting manufacturers followed suit, with different configurations to pass the UL test requirement. Some of these designs include internal plastic sealing devices, or compression gland rings without a split, and external sealing device on the locknut threads to prevent water entering the box. Regardless of the design, all have to pass the same UL raintight test parameters.
UL Listed nonmetallic (NM) sheath cable connectors are suitable for use with a single cable unless specifically tested for two cable usage. A concern with two cable usage is the fitting’s ability to withstand cable pullout forces normally encountered during installation. Per UL 514B, each cable is subjected to an individual pull test.
In addition, UL tests strap type connectors to ensure that when tightening the strap screws, the strap will not pierce the nonmetallic sheath of the cable, creating a possible short.Bridgeport’s Carton shipping labels will specify the type and number of nonmetallic cables for which the fitting has been UL Listed. Do not exceed the UL rating.
UL listing requirements are identical for both snap-in and locknut types of fittings. This includes assembly, bending, resistance, pull test, repeated resistance, and a ground fault current test.
Snap-in type connectors are required by code to be capable of withstanding ground fault current likely to be imposed on them, and offer equivalent grounding protection as locknut type connectors. Many snap-in products are used to reduce installation time or where tightening a locknut may be difficult.
UL Listed armored and metal clad cable connectors are suitable for grounding when installed in accordance with the NEC. Always refer to the carton label for listed cable type and material (aluminum or steel). The label will also specify the cable size range. Do not use cable smaller than noted on label, the clamping mechanism on the fitting may not function correctly and grounding integrity will be compromised.
Bridgeport’s snap-in fittings are designed only to work with UL Listed steel boxes which have a nominal .063″ wall thickness. Use with boxes made in other materials (i.e. plastic) or other thicknesses, is not recommended nor approved.
AC and MC snap-in type connectors are capable of withstanding ground fault currents likely to be imposed on them, and offer equivalent grounding protection as locknut type connectors. During the listing process at UL, AC and MC connectors are assembled to cable and subjected to a ground fault current test. These tests are necessary to comply with application requirements in the NEC.
Although different manufacturers’ conduit bodies may look the same, not all are suitable for ‘approved’ installations. Specific NEC requirements determine which conduit bodies may contain splices, taps, or devices.Conduit bodies provide access to the conduit system through a removable cover at a junction of two or more entries. Bodies may be used for changing the direction of the wiring systems, to aid in pulling of long wire runs, or to mount devices or make splices.
UL can ‘list’ conduit bodies as a fitting, which is tested under specification UL 514B. However, a fitting cannot contain a device or splice. UL can also ‘list’ the conduit body as a box, tested under specification UL 514A. Only the conduit body listed as a box is suitable for use with a device, splices, or taps.
Conduit bodies listed for use with splices, taps, or devices must be marked with the cubic inch volume and any special installation requirements, such as the use of wire pulling compound. The conduit body may also be marked with the maximum wire capacity if the body does not meet the NEC end stop to end stop dimensional requirement for wire pulling: 8 times the trade size for straight pulls, 6 times the trade size for angled pulls.
NEC Article 300.15 specifies that fittings can only be used with wiring methods for which they are designed and listed. Most manufacturers have received dual usage listings for these types of connectors; however, you should not assume all fittings have the dual listing. While the appearance of Metal Clad (MC) and Armored Cable (AC) connectors may be similar, the misuse of an AC cable connector can be significant enough to cause an unsafe installation with metal clad cable.
During the listing process at Underwriters Laboratories (UL), MC connectors are subjected to more stringent testing than a typical AC connector. Additional tests are necessary to comply with application requirements of metal clad cable in the NEC.
UL Listed metal clad cable connectors are suitable for grounding when installed in accordance with the NEC. ‘Dry Type’ MC connectors may be ‘concrete tight’ when taped and used with PVC coated metal clad cable (PVC jacket stripped back to fitting end stop).
Always refer to the carton label for listed cable type (corrugated, interlocked, or smooth) and material (aluminum or steel). The label will also specify the cable size range. Do not use cable smaller than noted on label; the clamping mechanism on the fitting will not function correctly and grounding integrity will be compromised.
The newest type of MC Cable – MCI-A, may require use of a special connector. Such fittings have been listed by UL for use with this cable type.
In 1998, UL began listing electrical hardware devices such as Beam Clamps. This was at the request of the electrical industry, including contractors, who became confused regarding the correct application and strength of Beam Clamps.UL Listed Beam Clamps are manufactured from malleable iron or steel with a hardened screw to secure the clamp to the beam. Clamps are tapped in two places for attachment of threaded rod, conduit hanger, or bridle ring.
UL Listed beam clamps are only for use with rigid, IMC, or EMT conduits. Spacing of clamps must comply with strap requirements found in the National Electrical Code.Refer to Bridgeport’s carton label for conduit size and type, maximum loading, screw torque, or any special assembly requirements.
NEC Article 501.30(B), exception (1), (2), (3) will permit the use of liquidtight flexible metal conduit and liquidtight connectors to be the sole equipment grounding conductor in Class 1, Division 2 locations. However, strict requirements must be met:
- Conduit and connectors must be UL Listed.
- Conduit cannot exceed 6 feet in length.
- Over-current protection in the circuit is limited to 10 amperes or less.
- It supplies other than power utilization loads
When installing ARMORED CABLE (Type AC), NEC Article 320 mandates the use of a insulating bushing (commonly referred to as Anti-Short or Redhead) between the metal sheath and the conductors. Fittings with insulated throats are not a substitute for the anti-short bushing.
When installing METAL-CLAD CABLE (Type MC), the NEC does not require the use of a Anti-Short insulating bushing. MC Cable conductors are usually wrapped with Mylar tape for protection; use of anti-short bushing is optional unless specified otherwise by the cable manufacturer.
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.
The UL 514B testing procedure requires the connector or coupling to be assembled to the conduit inside a special concrete form. Then Portland-type concrete is poured into the form and over test samples. Then the concrete slurry is vibrated to remove any trapped air, and allowed to cure. After concrete curing, the fittings are chipped out of the concrete and examined for concrete penetration.
Although compression style connectors and couplings pass these tests in all trade sizes because of the gland ring design, the set screw types may have difficulty conforming to UL or CSA concrete penetration requirements. When the set screw is tightened onto the conduit, the fitting and/or conduit 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 and CSA will accept product carton marking that specify “Concrete-Tight When Taped” on fittings that cannot pass testing, since the tape prevents entrance of concrete into the raceway. The taped joint must completely encircle the conduit/ fitting connection. We recommend using duct tape or similar type of durable tape.
Plastic insulating bushings must be used in conjunction with two locknuts when connecting threaded rigid or IMC conduit, containing No. 4 or larger un-grounded conductors, to boxes or enclosures. Bushings composed entirely of plastic cannot be used to secure conduit to the enclosure. A locknut is required on the inside and outside of the enclosure in addition to the plastic insulating bushing. Temperature rating of the plastic insulating bushing must not be less than the insulation rating of the conductors.
NEC Articles 320.30 and 330.30 denotes the different requirements for securing Armored and Metal Clad cables. Although similar in appearance, each cable has unique requirements. Armored cable [NEC Article 320.30(C)] must be secured at intervals not exceeding 4-1/2 feet and within 12″ of box or fitting. Metal Clad cable [NEC Article 330.30(B)] must be secured at least every 6 feet. Cables with four or fewer conductors “sized 10 AWG or less” must be secured within 12″ of box or fitting.
NEC Article 300.4(F) specifies that cable or raceway-type wiring may be installed in wooden stud grooves, to be covered by wallboard or similar covering, if protected by 1/16″ thick steel plate. The steel plate must have the same width as the stud, and must be securely fastened to the stud.