A main bonding jumper or a bonding jumper required by Section 250-26(a) shall be a wire, bus, screw, or similar suitable conductor. (b) Construction. Where a main bonding jumper is a screw only, the screw shall be identified with a green finish that shall be visible with the screw installed.
Likewise, people ask, what is the system bonding jumper?
For clarification purposes, a system bonding jumper is a conductor, screw, or strap that bonds the metal parts of a separately derived system to a system neutral point [250.2].
Beside above, what color is a grounding jumper? It is often phase taped green, however green is the required identification for the equipment grounding conductor, which serves a different purpose altogether. It could be a violation if white or orange is used, as those colors are used for other purposes. Black or bare copper is commonly used.
Beside this, where is the main bonding jumper located?
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.
What is the purpose of the main bonding jumper?
The primary purpose of the main bonding jumper is to carry the ground-fault current from the service enclosure as well as from the equipment grounding system that is returning to the source.
17 Related Question Answers Found
What is difference between bonding and grounding?
Bonding ensures safe electrical continuity while grounding ensures that all metal parts of an electrical circuit that an individual might contact are connected to the earth, thus ensuring zero voltage. 3. Bonding is achieved by using a wire while grounding is achieved by using a rod.
How do you size a bonding jumper?
Supply-side bonding jumpers: Size these per Table 250.66, based on the largest ungrounded conductor within the raceway. If the ungrounded supply conductors are larger than 1,100kcmil copper or 1,750kcmil aluminum, size the bonding jumper at least 12.5% of the area of the largest set of ungrounded supply conductors.
What is main bonding?
Main Bonding is the use of a separate thick (10mm) green and yellow copper cable, to connect the Water, Gas and Oil services to the Earth Terminal in or adjacent to your consumer unit.
Do you bond a service disconnect?
This “main bonding jumper” that is required at the service disconnect (aka first means of disconnect, aka service equipment) that ties grounds to the neutral conductor is required in every enclosure that contains a means of disconnect (switch) for that electrical service.
Can ground and neutral be connected together?
No, the neutral and ground should never be wired together. This is wrong, and potentially dangerous. When you plug in something in the outlet, the neutral will be live, as it closes the circuit. If the ground is wired to the neutral, the ground of the applicance will also be live.
Do you bond a transformer?
You must bond a transformer secondary that operates at more than 50V [250.20(A) and 250.112(I)] to an effective ground-fault current path to ensure dangerous voltage levels imposed by lightning, line surges, or unintentional contact with higher-voltage lines won’t remain [250.2(A)(3)] on the system.
What size are bonding conductors?
1 requires main protective bonding conductors to have a cross-sectional area (csa) of not less than half that required for the earthing conductor and not less than 6 mm2, but need not be more than 25 mm2 if the conductor is of copper or, if of another metal, a csa affording equivalent conductance.
Where an equipment bonding jumper is installed on the outside of a raceway?
The equipment bonding jumper shall be permitted to be installed inside or outside of a raceway or enclosure. Where installed on the outside, the length of the equipment bonding jumper shall not exceed 6 ft (1.83 m) and shall be routed with the raceway or enclosure.
What type of material is permitted for use as a bonding conductor?
Rule 10-804 Material for Bonding Conductors In applying Rule 10-804(c), a plastic film installed under a ground level concrete slab is not considered as isolating the conduit or concrete slab from contact with earth therefore a bonding conductor is required.
What is an equipment grounding conductor?
You use an equipment-grounding conductor (EGC) to ground the noncurrent-carrying metal parts of equipment. Its function is to keep your equipment as close as possible to ground potential and provide a safe path for ground-fault current to flow. A properly sized EGC protects. James Stallcup Sr.
What is a separately derived system?
By definition, a separately derived system is a “premises wiring system whose power is derived from a battery, a solar photovoltaic system, or from a generator, transformer, or converter windings, and that has no direct electrical connection, including a solidly connected grounded circuit conductor, to supply
Which NEC table is used for sizing grounding electrode conductors?
In the 2014 NEC, Table 250.66 has only one purpose; sizing the grounding electrode conductor. A new table has been added for everything else besides the grounding electrode conductor, that used to be sized from Table 250.66.
How do you ground a water meter?
If you use your home’s main water pipe to ground the electrical system (and many homes do), you should attach a jumper wire around the water meter in order to provide better path for the electricty ground path. If no jumper wire is installed, a surge in electricity could cause damage to the water meter in some cases.
What is the largest size grounding electrode required?
Grounding-electrode conductor size A 4 AWG copper conductor meets the requirement for the grounding-electrode conductor where 20 feet or more of ½-inch or larger reinforcing steel embedded in concrete that is in contact with the earth is the grounding electrode.
How do you measure the size of a parallel grounding conductor?
When circuit conductors are run in parallel [310.4], an equipment grounding conductor must be installed with each parallel conductor set and it must be sized in accordance with Table 250.122, based on the rating of the circuit overcurrent device [250.122(F)].
Where is a grounding bushing required?
You need a bonding bushing if: Your raceway contains service conductors. Your raceway contains grounding electrode conductors. In fact, you may need one on both ends, for GEC performance.
Are grounding bushings required on Transformers?
For the installation described in the OP bonding bushings are not required. As George said this is an SDS not a service so the service raceway bonding requirements do not apply. I’ve seen many a bonding bushing on transformers, but if your using FMC they’re serving no real purpose and are not required.