T&B Conduit Fittings 1 - TNB.COM

1 Page 1 of 4 Ref NEC Article 358 electrical Metallic Tubing (EMT) is similar to rigid steel Conduit but is much Iighter weighing approximately 40 percent as much as rigid steel Conduit of the same nominal size, EMT can be used for both exposed or concealed work provided, where during installation or afterwards, it is not subjected to severe physical damage. Use of EMT is restricted to systems not exceeding 600 volts and to non-hazardous locations except.(Class II Division 2 NEC Sections (B), (A) and (B)).Galvanized Steel EMT installed in concrete on grade or above generally requires no supplementary corrosion protection. However, when installed in concrete below grade level and in contact wIth soll or cinders supplementary corrosion protection consisting of a protective coating of bitumastic or asphalt base palnt or plastic is generally applied. According to NEC Section (3), EMT run in or under permanently moist cinder ll must be encased in at least two aches of ainder free concrete unless the Conduit is at least 18 inches below the EMT cannot be directly embedded in concrete containing soluble chlorides such as calcium chloride, unwashed beach sand, sea water or corel bearing adequately treated with a protective coating of bitumastic or asphalt base paint or plastic coating the raceway can be installed in concrete containing Section requires that in wet locations where walls are frequently washed or where there are surfaces of absorbent material the entire wiring system including boxes, ttings.

2 Conduits and cables must be supported such that there is at least 1/4 inch air space between it and the supporting and couplings are required to be of concretetight type when embedded in masonry or concrete and listed for wet location when installed in wet locations (NEC Section ).According to NEC Section (G), where No. 4 or larger underground conductors enter or leave a Conduit an insulating bushing with a smooth well rounded insulating surface must be provied to protect conductors unless the teminating tting is equlpped with an insulated throat, rmly secured in place providing equivalent protection, The insulating bushing or insulating material must have a temperature rating of not less than the insulation temperature rating of installed Section requires that the raceways be metallically joined together into a continuous electric conductor and must be mechanically connected to all boxes, ttings and cabinets as to provide effective electrical is not permitted to be threaded.

3 Cut ends of tubing are required to be reamed. Code requires that EMT be adequately supported and restricts bends in one run to the equivalent of four quarters 360 degrees NEC Article 358. electrical Metallic Tubing2. ANSI Steel electrical Metallic Tubing (EMT).3. Standards for Safety. electrical Metallic ANSI for Rigid Metal Conduit and electrical Metallic 514B. Conduit Tubing and Cable Fittings6. Conduit , Metal, Rigid, and Bend and Elbow, electrical Conduit , Thinwall type (EMT).7. Fittings for Conduit , Metal, Rigid, (Thickwall & Thinwall (EMT) Type).8. NEMA FB-1. Standards Publication. Fittings , Cast Metal, Boxes, and Conduit Bodies for Conduit , electrical Metallic Tubing, and CEC Section electrical Metallic CSA No. Safety Standards for electrical Metallic Tubing11. CSA No. Safety Standards for Conduit , Tubing and Cable Series 3650 bonding & grounding Wedge1.

4 T&B Series 142 Locknut2. T&B Series 122 Metallic Bushing3. T&B Series 3650 bonding & Grounping Wedge4. T&B pressure (crimp type) terminal lugAcceptable Method for bonding Following (I) Service Equipment NEC Sec. (II) bonding for Circuits over 250 volts. NEC Sec. (III) bonding in Hazardous Locations. NEC Sec. Sec. Sec. Sec. installed willl a bonding jumper, acceptable method of bonding where unpunched rings remain around concentric or eccentric knockouts in sheet metal boxes or enclosures.(NEC Sec. (B)).Suggested SpecificationsBonding and grounding Wedge (Series 3650) bonding and grounding Wedges installed to effectively bond terminating tting or metal Conduit to a cabinet. box, enclosure or an auxiliary gutter or to install bonding jumper around concentric or eccentric knockouts shall be of the type as manufactured by Thomas & Betts-Series and grounding Wedge shall be of rugged bronze/tin plated or steel/electro zinc and SpecificationsConduit Fittings Typical Installations Using Thomas & Betts bonding and grounding WedgeElectrical Metallic Tubing (EMT)1324 Phase ConductorsThreaded Rigid Metal Conduit or Intermediate Metal ConduitEquipment bonding JumperSheet Metal Box orEnclosure with unpunched concentric or eccentric ringsremaining around knockout opening331122 grounding electrodeconductor grounding electrode Conductor enclosure(Rigid Metal Conduit orIntermediate Metal Conduit )Service Raceway Rigid Metal Conduit or Intermediate Metal ConduitGround Bus(Service Equipment bonding Jumper)Service Endosure344 Page 2 of 41.

5 T&B Series 142 Locknut2. T&B Series 106 bonding Locknuts3. T&B Series 122 BushingSuitable ror bonding Raceway, EMT or Terminating fitting to a sheet metal box or enclosure where(a) No unpunched concentric or eccentric rings remain around the knockout(b) Ordinary locknut is unacceptable for bonding purposes such as(i) Service Equipment Enclosures Nec Sec. (ii) bonding for circuits over 250 volts (where required) NEC Sec. (iii) bonding in Hazardous Locations regardless of the voltage of the systemNEC Sec. Sec. Sec. Sec. T&B Series 142 Locknut2. T&B Series 3870 bonding & grounding Bushing(Threaded)3. T&B Series 5262 Sealing 'O' Ring4. T&B Typical Bolted or Pressure LugMultiple bonding of Service Raceways Where Service Entrance Conductors are Paralleled in Two or More Raceways, NEC Sec. , , and bonding jumper to Assure electrical Continuity Between Isolated Sections of Raceway (NEC Sec.)

6 Suggested SpecificationsInsulated grounding and bonding bushing (Series 3870)Where code requires bonding and grounding of single or muitiple metal conduits, or positive bonding and grounding of metal Conduit to the box, enclosure or auxiliary gutter, the end of the Conduit shall be equipped with an insulated metallic grounding and bonding bushing such as Series 3870 manufactured by Thomas & Betts, grounding and bonding bushings used shall be approved for the purpose and(i) Shall be of malleable iron/steel/aluminum construction adequately protected against corrosion.(i) Installing bonding jumper around unpunched concentric or eccentric knockouts in sheet metal box or enclosure (NEC Sec. )(ii) Installing bonding jumper in hazardous locations where "locknut bushing" or "double locknut" type of contact is unacceptable method for bonding purposes (NEC Sec.)

7 (A), (A), and (A)).Suggested SpecificationsBonding Type Locknut (Series 106)Where drawings indicate installation of a bonding type locknut to effectively auxiliary gutter, the locknuts installed shall be of hardened steell/lmalleable iron construction, electro zinc plated. such as Series 106 manufactured by Thomas & and SpecificationsConduit Fittings Typical Installations Using T&B bonding LocknutTypical Installations Using bonding and grounding WedgeBonding Service Equipment (NEC Sec. )LOAD SIDE OF SERVICE EQUIPMENT221313 Service Raceway(Rigid Metal Conduit or intermediate metal Conduit ) grounding electrode conductorService enclosure with no unpunched rings around knockoutGround busGrounding Electrode Conductor EnclosureThreaded Rigid Metal Conduit or Intermediate Metal Conduit145 Threaded Rigid Metal Conduit or Intermediate Threaded Rigid Metal Conduit or Intermediate EQUIPMENT bonding 11122 ABCN232orBUS BARSSERVICE ENCLOSURGROUND BUSR igid metal Conduit or Intermediate Metal EQUIPMENT ENCLOSUREB onding required by NEC Method per NEC BUSGROUNDING ELECTRODECONDUCTOR ENCLOSUREGROUNDING ELECTRODEB onding jumper required by and CLAMPGROUNDING ELECTRODE CONDUCTORSERVICE Conduit (Threaded rigid metal Conduit or intermediate metal Conduit )

8 bonding required by NEC Section and BUSPage 3 of 4 Threadless opening in a sheel metal box or jumper around concentric or eccentric rings required by NEC Sec. 1: Where threaded or threadless Conduit terminates into a threadless opening in a sheet metal box or enclosure with or without concentric or eccentric of bonding :For under or over 250 volts circuits, service equipment and hazardous locations (where applicable) provided no unpunched rings remain around the knockout. For under or over 250 volts circuits, service equipment and hazardous locations (where applicable) with or without unpunched rings around the Threaded or threadless rigid metal Conduit or intermediate metal conduit2. T&B-Series 8123 or 8124 Threadless Connectors3. T&B Series 8125 Set Screw Connector 4. T&B Series 370 or H050-TB Sealing Hub (Bullet Hubs) 5. T&B Series 140 Locknuts 5.

9 T&B Series 106 bonding Locknut 7. T&B Series 3870 bonding & grounding Bushing8. T&B Sta-Kon or Color-Keyed Threaded hub in a cast metal enclosureCase 2: Where threaded or threadless Conduit terminates into a threaded hub in a cast metal of bonding :For(1) 120/208 or 120/240 volts circuits (NEC )(2) Over 250 volts circuits (NEC )(3) Service equipment (NEC )(4) Hazardous Locations (Where applicable) (NEC , , and Threaded or threadless rigid metal Conduit or intermediate metal T&B Series 8123 Threadless Connector3. T&B Series 8125 Set Screw ConnectorRigid Metal Conduit or Intermediate Metal ConduitRigid Metal Conduit or Intermediate Metal ConduitTables and SpecificationsConduit Fittings1131285657432111 CONCRETE TIGHTCONCRETE TIGHTRAINTIGHTPage 4 of 4 Case 3: Where threaded Conduit terminates into a threadless opening in a sheet metal box or of bonding for 120/208 volt or 120/240 volts circuits (other than service equipment)Method of bonding for over 250 volts circuits 480/277 volt systems and those operating over 600 volts (other than service equipment)Note: (Any of the bonding methods descnbed for sevices may also be used)Case 4: Where threaded Conduit terrninates into a threadless opening in a sheet metal box or of bonding for under or over 250-volts, for service equipment and for hazardous locations where : bonding jumper required by Sec.)

10 Threaded rigid metal Conduit or intermediate metal conduit2. T&B Series 142 Locknuts 3. T&B Series 122 Bushing, Metallic4. T&B Series 3650 bonding Wedge5. T&B Series 3870 or BG050-14-4 bonding & grounding Bushing6. T&B Typical Mechanical or Pressure Type ConnectorNote: For wet locations applications a sealing ring, T&B Series 5262, may be used between outside of box or enclosure and the outside 3: (con't) Where threaded Conduit terminates into a threadless opening in a sheet metal box or Threaded rigid metal Conduit or intermediate metal conduit2. T&B Series 142 Locknuts3. T&B Series 122 Bushing. Metallic4. T&B Series 106 bonding Locknut5. T&B Series 3850 bonding Wedge Method of bonding : For(I) Over 250-volts circuit 480/277-volts systems and those operating over 600 volts(II) Service equipment(III) Hazardous locations where applicableRigid Metal Conduit or Intermediate Metal ConduitRigid Metal Conduit or Intermediate Metal ConduitRigid Metal Conduit or Intermediate Metal ConduitTables and SpecificationsConduit Fittings63421125111225533463 Threadless opening in a sheet metal box or enclosure11222433