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When concentric or eccentric knockouts are encountered with service equipment, a bonding jumper would be required. If the integrity of the concentric or eccentric knockouts has been compromised during installation, a bonding jumper should be provided to ensure compliance with all of the requirements of the NEC.
Why do you need a bonding bushing?
Bridgeport’s grounding and bonding bushings are used to properly bond and terminate service conduits to a cabinet, box or enclosure. Adjustable lay-in lugs accept and position conductors for simple access during installation. The plastic liner prevents damage to the wire jacket during installation and use.
What is a bonding locknut?
Used in harsh vibration environments to fasten threaded conduit to unthreaded opening in a box or enclosure.
Is a locknut required with a grounding bushing?
Where threaded conduit terminates into a threadless opening, a locknut shall be provided both inside and outside the box or enclosure and the conduit end shall be fitted with an insulating bushing. In wet locations, a suitable gasket shall be provided between the outside locknut and the opening.
What are eccentric knockouts?
Eccentric knockouts look like crescent moons, staggered around the outside of a circle. Individual “wedges” can be removed, without going completely around the circle.
What is bonding jumper in electrical?
A bonding jumper is a reliable conductor to ensure the required electrical conductivity between metal raceways required to be electrically connected.
What is a ringed knockout?
“There is a ringed knockout present, which means that a bonding jumper based on 250.122 is required. I would also cite 110.12 for a violation of neat and workmanlike installation.
Where do you need grounding bushings?
The National Electrical Code (NEC) Articles 250.64 & 250.92 require the use of a grounding bushing. In addition, NEC Articles 344.46 & 300.4(G) require a bushing with conductors 4AWG or larger. 1. Prepare conduit by squarely cutting the conduit to the desired length and deburring conduit end.
What is grounding bushing?
Grounding-Bushing: This is a threaded-metal ring with a lug attached, that we screw down tightly onto the end of a threaded-metal conduit, threaded-metal conduit connector, or any other threaded-metal electrical component, such as a metal offset nipple (the kind we might use to connect a meter-base to an electrical Jul 31, 2018.
What is plastic bushing?
Plastic bushings are chemical resistant, resist high temperatures up to +482°F, and are lubrication- and maintenance-free. They are available at a low cost, have a long service life, manage high loads, can be used in wet environments, are FDA approved, and have many other useful features.
Can you use EMT as a ground?
Electrical metallic tubing (EMT) is one type of acceptable equipment grounding conductor listed in Section 250.118. When installed properly and the fittings are made up wrench-tight, EMT is an excellent equipment grounding conductor.
What is a grounding lug?
[′grau̇nd ‚ləg] (electricity) A lug that connects a grounding conductor to a grounding electrode.
What does a stop nut do?
A locknut, also known as a lock nut, locking nut, self-locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque.
What is the grounding electrode conductor?
The grounding electrode conductor connects the grounding electrode to the electrical system. When wind, tree limbs or other influences cause connection between the two different voltage systems, line-voltage surges can occur, causing potential damage to the electrical equipment and the electrical system.
What is a locknut bushing?
– Used to secure an ordinary nut from working loose by locking itself when screwed down tight. – For rigid conduits. Bushing. – Zinc die-cast aluminum. – Used with locknuts to terminate RSC or IMC conduit to enclosure/box.
When grounding electrode conductors are installed in metal conduit for physical protection the conduit must be ___?
A 6 AWG or larger copper or aluminum grounding electrode conductor exposed to physical damage shall be protected in rigid metal conduit (RMC), intermediate metal conduit (IMC), Schedule 80 rigid polyvinyl chloride conduit (PVC), reinforced thermosetting resin conduit Type XW (RTRC-XW), electrical metallic tubing (EMT),.
Are reducing washers listed for bonding?
Furthermore, the Underwriters Laboratories (UL) subject all listed reducing washers to a resistance test and a current test. These tests are in the standard UL 514B, and also in UL 467. Nevertheless, at least one manufacturer recommends that reducing washers be bonded around.
What does concentric mean in electrical?
concentric cable means a composite cable comprising an inner conductor which is insulated and one or more outer conductors which are insulated from one another and are disposed over the insulation of, and more or less around, the inner conductor; Sample 1.
Which of the following is not permitted to serve as an equipment grounding conductor?
Flexible metal conduit is never allowed as an equipment grounding conductor when flexibility is necessary after installation.
Why is bonding required?
Rather, bonding is required because experience has shown that when people are entrusted with the money or property of another, there will be instances when individuals will cause a loss through fraud or dishonesty. Bonding is therefore required to insure the union against such a loss.
Where do you put the main bonding jumper?
There are many different bonding jumpers installed in an electrical system, but there is only one main bonding jumper, and it is located at the electrical service. It is defined in Article 100 as the connection between the grounded circuit conductor and the equipment grounding conductor at the service.
When properly bonded a system will establish?
Article 100 of the NEC defines bonded (bonding) as “connected to establish electrical continuity and conductivity.” Bonding metal parts, such as enclosures and raceways, ensures that they are all continuous on an effective ground-fault current path (EGFCP) that references back to ground (earth).
What is the minimum size aluminum equipment grounding conductor required for a feeder that is protected by a circuit breaker rated at 4000 amperes?
Table 250.122 Minimum Size Equipment Grounding Conductors for Grounding Raceway and Equipment Rating or Setting of Automatic Overcurrent Device in Circuit Ahead of Equipment, Conduit, etc., Not Exceeding (Amperes) Size (AWG or kcmil) Copper Aluminum or Copper-Clad Aluminum* 2500 350 600 3000 400 600 4000 500 750.
Is a ground wire required in metal conduit?
2 Answers. Conduit (RMC, IMC or EMT) is an NEC-accepted ground path. So, if the wires are in steel conduit, no OTHER ground wire is required.
Are bushings required on PVC conduit?
The important part is bolded above – you need a bushing unless your fitting provides equivalent protection – that is, equivalent to the protection a bushing provides.
What is the use of bushing?
Bushings are akin to thin tubes most commonly used for machinery with rotating or sliding shafts to improve efficiency and reduce vibration and noise. Bushings can be used for drilling operations in drill jigs, hydraulic external gear pumps and motors.
