Grounding & Bonding Chapter 8
The device is attached to the cover with either rivets or thread-locking or screw-locking means. The raised cover provides a flat no-raised portion to contact the grounded metal box.
A listed exposed work cover shall be permitted as the grounding and bonding means for a receptacle under these conditions___,___.
Section 250.104(A) A: must be accessible
Bonding connections to metal water piping systems ____.
Section 250.102 (B), 250.8, A:Exothermic welding, listed pressure connectors, listed clamps
Bonding jumpers are required to be attached to circuits and equipment by means _____, or other listed means.
UL White Book Category (QCRV), 250.92(B) A: are not suitable for grounding and bonding in circuits over and under 250 volts
Concentric and eccentric knockouts in enclosures such as wire-ways and panel boards____.
Section 250.148, A: suitable
Except for isolated receptacles, where circuit conductors are spiced within a box, or terminated to equipment or devices within or supported by he box, equipment grounding conductors associated with those circuit conductors must be spliced or joined with ____devices.
Section 250.98 A: equipment bonding jumper or other means
Expansion joints or telescoping sections of metal raceways must be made electrically continuous by the use of an _____ or other means.
Section 250.146 (D), A: building or structure
For an isolated grounded receptacle an equipment grounding conductor is permitted to pass thorough one or more panel-boards, boxes, wire ways, or other enclosures wiring the same____ to terminate at an equipment grounding terminal of the applicable separately derived system or service.
Section 250.97, A:250
For circuit having a voltage exceeding___ volts to ground, the electrical continuity of metal raceways and cables with metal sheaths that contain any conductor other than service conductors shall be ensured by one or more of the methods specified for services in 250.92(B), except for (B)(1)
Section 250.104(D)(2) A: at leas one of
For surface-mounted boxes intended for direct metal-to-metal contact for grounding of receptacles, ______ the insulated washers used to retain the screws must be removed so there is direct metal to metal contact from the device yoke to the box, unless the receptacle is listed as self-grounding..
Section 250.122 and Table 250.122, 250.102(D) A: 3 AWG copper or 1 AWG aluminum
If four metal raceways have their conductors protected by over-current protective devices sized at 400, 300, 225 and 125 amperes and leave the bottom of an open switchboard or motor control center, the minimum size of a single equipment bonding jumper to be used to bond them together is____.
Section 314.3, Exceptoin Nos. 1 and 2, A: internal bonding means are provided between all raceways, integral bonding means with a provision for attaching an equipment bonding jumper inside the box is provided, internal bonding means are provided between all cables
Metal raceways or metal-jacketed cables are permitted to be used with nonmetallic enclosures only where____?
In text book 250.104(B) A: gas piping and pneumatic systems, waste, drain and vent lines, oxygen, air and vacuum systems
Other common systems and metal piping that must be bonded include metal____.
Section 250.104(C) A: it is exposed, interconnected to form a metal building frame, and not intentionally grounded.
Structural metal must be bonded where____.
Section 250.104(B) A:bonding
The equipment grounding conductor for the circuit that may energize any other metal piping systems can be used as the _____ means for other metal piping systems.
Section 250.146 A: be bonded to the exposed structural metal that is interconnected to form the building frame
The grounded conductor of a separately derived systems shall_____.
Section 250.100, 250.92(B) A: hazardous (classified) locations
The lock-nut/bushing and double lock-nut types of installations are not acceptable for bonding in ____.
Section 240.104(A)(1) A: electrodes
The metal water piping system is permitted to e bonded to the services equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to one or more grounding?in mathematics and physics refers to a region in space where every point in it is at the same potential____.
Section 240.104(A) A: accessible
The points of attachment of the bonding jumper to the metal water piping systems re required to be___...
Section 250.146(A) A: Table 250122
Where an equipment bonding jumper is used to connect a grounding type receptacle to a grounded metal box, it shall be sized in accordance with _____.
Section 250.102(E)(1)&(E)(2), A:1.8 m (6ft)
Where the equipment bonding jumper is installed on the outside of a raceway, generally the length is limited to not more than____. In addition the equipment bonding jumper must be routed with the raceway...
Section 250.146(A) A: Bonding
_____ metallic parts together puts the parts at the same potential.
equipotential
in mathematics and physics refers to a region in space where every point in it is at the same potential
bonded (bonding)
is the practice of intentionally electrically connecting all exposed metallic items not designed to carry electricity in a room or building as protection from electric shock. If a failure of electrical insulation occurs, all bonded metal objects in the room will have substantially the same electrical potential, so that an occupant of the room cannot touch two objects with significantly different potentials. Even if the connection to a distant earth ground is lost, the occupant will be protected from dangerous potential differences.