Ground & Bonding II Study

Where the grounding electrode system for the DC side of a PV installation is installed using a 6 AWG copper grounding electrode conductor, and the grounding electrode conductor for the AC system is 1 AWG copper, what is the minimum size required for the bonding conductor that must connect the two grounding electrode systems together?

1 AWG Copper

Secondary circuits for underwater lighting installed in swimming pools or spas are not permitted to be grounded under which of the following conditions?

1.) Where listed for swimming pool or spa use 2.) Where the transformer is an isolation-type with a grounded metal barrier between the primary and secondary windings

Metal water piping systems in seperate buildings or structures shall be bonded to which of the following?

1st -->250.104 Bonding of Piping systems and Exposed Structural Metal: LOOK AT IT DEEPLY, GO TO THE NEXT PAGE, 250.104(3) Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).

What is the minimum size copper bonding jumper required for a metal water piping system (not a grounding electrode) in a building or structure supplied by a 400-ampere feeder when the largest ungrounded feeder conductor is 600 kcmil copper

3 AWG 250.104

Which of the following is typically not a separately derived system?

Autotransformer with a grounded conductor common to both the primary and secondary Examples of a seperately derived system: DC battery system with 480 output, Generator with a transfer switch that switches the grounded conductor of the system, transformer with a 480V, 3 phase, delta primary (input) and a 208Y/120V secondary (output)

If a building has a metal underground water pipe electrode and an in-ground support structure for the grouding electrode system, which of the following grouding electrodes are required to be used for grounding a separately derived system?

Both electrodes must be used 250.50 Grounding Electrode System

__?__ on neutral conductor supplying a building or structure housing livestock can result in elevated levels of stray current in conductive components such as metal flooring, metal rails, and feeding troughs

Inappropriate neutral-to-ground connections

For PV systems that are stand alone units, the grounding electrode system has to meet provisions in Part VIII of Article 250 and the DC system grounding electrode conductor is required to be as large as the largest output conductor supplied by the PV system or at least 8 AWG, whichever is larger.

Part VII Article 250, 250.166 - 8 AWG

The identification of the equipment grounding conductor connected to the equipment grounding terminals of use of isolated ground receptacles installed in patient care spaces outside a patient care vicinity shall be installed in accordance with which of the following?

Shall include an equipment grounding conductor with green insulatio that has one or more yellow stripes along its entire length. Note: 517.16 addresses the use of isolated ground receptacles. Section 517.16(B) addresses the use of isolated ground receptacles outside of patient care vicinity. 517.16(B)(1) addresses the use of isolated ground receptacles installed in patient care spaces outside of the patient care vicinity.

Which of the following are methods to reduce static electricity problems in hazardous locations?

arc-fault circuit interrupter protection & install equipotential bonding and grounding systems

Where a pole-mounted electric sign is connected to a grounding electrode, the electrode is referred to as an ____grounding electrode

auxiliary

Equipment and systems that are not services, such as PV systems, and are connected to the line side of service equipment, shall be permitted to be ____ systems

either ungrounded or grounded.

On an ungrounded system, the occurence of the first ground fault (not a short circuit or line to line fault) on the system will cause the overcurrent protective device for the service, feeder, or branch circuit to open

false

Remote parts of a section sign or outline lighting system supplied by a Class 2 power supply are required to be bonded to the equipment grounding conductor of the branch circuit supplying the system

false

The connection of the grounding electrode conductor to the grounded conductor of the separately derived system is required to be made at a different location than the system bonding jumper connection

false

The system bonding jumper for a separately derived system is permitted to extend beyond the enclosure where it originates

false

When a separately derived system is installed outside the building or structure it supplies, a grounding electrode connection is not required at the outdoor source location

false

The grounding electrode conductor for a separately derived system is required to be connected to the grounded conductor at the same location where the ___ is installed

system bonding jumper

One of the most important elements of farming wiring systems, especially where dairy cattle are involved, is to isolate the __?__ from the equipment grounding conductor and non-current carrying metal parts of the electrical system at barns, milking parlors, and so forth

system neutral conductor

If a generator supplies standby power for a separate building, a separate disconnecting means where the feeder arrives at the building or structure is not required if _____

the disconnecting means is located within sight of the building or structure supplied & the generator disconnect is readily accessible 700.12(D)(5), 701.12(D)(5), 702.12 & 445.18

A grounding electrode system is generally required for each building or structure served by a feeder

true

Devices listed and identified for bonding metallic frames of PV modules shall be permitted to bond exposed metallic module frames to the metal frames of the PV modules

true

Equipment associated with pools and similar installations is generally required to be connected to a branch circuit that includes an insulated copper equipment grounding conductor

true

If a generator is installed on a premises wiring system, it must be grounded as a separately derived system if there is a switching action in the grounded conductor through the transfer switch

true

In hazardous locations, it is vital to have effective grounding and bonding to facilitate fast overcurrent protective device operation and prevent explosions

true

In health care facilities, those isolated power circuits in hazardous (classified) inhalation anesthetizing locations are required to be supplied by an isolation transformer or other ungrounded source and are not permitted to be grounded

true

Isolated grounding type receptacles are not permitted to be installed in patient care vicinities of health care facilities

true

It is never Code-compliant to install a feeder to a separate building or structure without an EGC or supply-side bonding jumper for a new installation

true

PV array equipment grounding conductors and grounding electrode conductors not larger than 10 AWG installed in raceways are permitted to be solid

true

The feeder run from the service disconnecting means or the feeder disconnecting means located no more than 30' from the mobile home must contain an insulated grounded (neutral) conductor and a separate equipment grounding conductor

true

The neutral of a high impedance grounded neutral system is required to be fully insulated, and no equipment grounding or equipment bonding connections are permitted on the supply side of the impedance device

true

Each agricultural building or structure has to meet the provisions in 250.32 and has to meet the sizing and connection rules in 547.9(B)(1),(2), and (3). Therefore, the minimum size required for the EGC must be no smaller than the largest supply conductor for the building if the same conductor material is used.

true.

Where a system is grounded, the grounded (usually neutral) the conductor(s) in sizes 4 AWG and larger must be identified generally by which of the following means?

200.6

What does the NEC indicate that the phase-to-ground voltage should be for an ungrounded 240 V, delta connected system?

240 V: Typically, the phase to ground voltage of an ungrounded system will be the result of distributed leakage capacitance and will vary from point to point on the circuit depending on the length of the run. There is no solidly grounded conductor of an ungrounded system. Review Voltage to Ground Article 100.

If the overcurrent protective device is not located on a generator outside that supplies a separate building or structure, then the feeder is on the line side of the overcurrent device. What is the minimum size supply-side bonding jumper (copper) required with a 400 ampere feeder from an outdoor generator to the building disconnecting means? (Note: the size of the largest ungrounded phase conductor supplied by the generator is 750 kcmil aluminum or coper clad aluminum)

240.102(D) Equipment Bonding Jumper on the Load Side of an Overcurrent Device. "feeder is on the line side of the OCD" -->sized in accordance with 250.122

Strengthened methods of bonding are required for metal raceways in hazardous locations where the voltage to ground exceeds.....

250.100 regardless of voltage level. An ignition source can be the spark from a system with very little voltage and can ignite an explosive atmosphere

If overcurrent protection is not provided where the conductors originate at a grounded separately derived system source supplying a separate building or structure, the installation must comply with

250.30(A)

NEC ____ provides the requirements for grounding of electrical systems and equipment at buildings or structures that are supplied from a feeder(s) or branch circuit(s)

250.32

If overcurrent protection is provided where the conductors originate at a grounded separately derived system source supplying a separate building or structure, the installation must comply with _____?

250.32(B)(1)

An exception applying only to existing premises wiring systems permits the continued use of the grounded conductor for grounding at seperate buildings under which of the following restrictive conditions

250.32(B)(1) Exception No: 1

Performance requirements for grounded electrical systems are provided in ___ of the NEC

250.4 :The key in this question is to focus on the grounded system performance requirements

If the overcurrent protective device is located on a generator outside that supplies a separate building or structure, then the feeder is on the load side of an overcurrent device. In this case, the equipment bonding jumper (load side) with the feeder is sized based on the requirements in Section 250.102(C):

250:102(C) says Supply-side Bonding jumper, that is a false. But, look at 250.102(D) Equipment Bonding Jumper on Load Side of an Overcurrent Device. Read your questions carefully, they're a lot closer than you think.

Where a DC system, other than a 3-wire balancer set, has a 250 kcmil copper grounded (neutral) conductor connected, the grounding electrode conductor shall not be required to be larger than ____?

3/0 copper 250.166

Which of the following systems is not required to be grounded because, if grounded, the phase-to-ground voltage would exceed 150?

480V, 3 Phase, delta system

If the voltage on the secondary side of a transformer is less than ____ and the voltage on the primary side of the transformer exceeds _____ to ground, the secondary side shall be grounded

50V/150V

The term patient care vicinity refers to a distance of ____ horozontally from the nominal patient bed location in a health care facility

6'

What is the minimum size bonding conductor required for bonding metal parts associated with the high voltage secondry circuit for a neon sign or outline lighting system?

600.7 (B)(7)

What is the minimum number of equipment grounding conductor paths required for a feeder supplying branch circuits that serve a patient care space?

Answer: 1. the requirements in 517.13 apply to the branch circuits serving patient care spaces. Feeders are generally only required to provide one EGC in accordance with 215.6, which could be the raceway or wiring method that qualifies as an EGC in accordance with 250.118.

Metal water piping and interconnected metal building framing that exists in the area served by a separately derived system is required to be bonded to the grounded conductor of that separately derived system, and _____ is used to size this bonding jumper or conductor

Table 250.102(C)(1)

The size of the grounding electrode conductor for a seperate building or structure shall generally not be smaller than the sizes provided in _____

Table 250.66, based on the size of the largest ungrounded conductor of the feeder

A separately derived system is required to be grounded in accordance with 250.30(A), and it is located 50' from a building structural metal electrode and 100' from a metal water pipe electrode. Which of the following grounding electrodes is required to be used to meet the minimum requirements of the NEC?

The system shall be grounded by connection to the building grounding electrode system: The system shall be grounded by connection to the building electrode system. 250.30 (A)(4) Grouding Electrode

If the overcurrent protective device is not located on the generator outside that supplies a seperate building or structure, then the feeder is on the line side (supply side) of the overcurrent device. In this case, the supply-side bonding jumper with the feeder is sized based on the requirements in 250.102(C).

True: 250.102(C) Supply Side Bonding Jumper

Other than substations installed on a temporary basis, to comply with the grounding of systems supplying portable or mobile equipment requirements for systems supplying such equipment over 1000 volts, exposed non-current carrying metal parts of such portable or mobile equipment shall be connected by a(n) _____ to the point at which the system neutral impedance is grounded

equipment grounding conductor

Class 2 load-side circuits for suspended ceiling low-voltage power grid distribution systems are required to be supplied by grounded systems

false

Ground-fault circuit interrupter protection for personnel is required for receptacles installed in those Category 1 (critical care) spaces where a toilet and basin are installed within the patient room

false

If a feeder to a separate building or structure is installed in rigid metal conduit, the conduit is not permitted to serve as the required equipment grounding conductor

false

Metql faceplates on switches and receptacles installed in patient care locations are required to be connected to two equipment grounding conductor paths that are specified for branch circuits in Section 517.13

false

Where a delta-connected system over 1,000 V is used to supply portable or mobile equipment, a neutral point and system neutral are not permitted to be derived for grounding purposes

false

Where supplying portable or mobile equipment, electrical systems of over 1,000 V must not be grounded

false

systems supplying cranes that operate over Class III locations are required to be grounded

false

The disconnecting means installed in the feeder supplying a separate building or structure has to always be suitable for use as a service equipment

false NEC 225 Part II: Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuits(s) -->225.36 for the requirements on type of disconnects installed on feeders. Where applied in accordance with 250.32(B), Exception, it shall be suitable for use as service equipment

Where flexible metal conduit is installed for a 20 ampere circuit in a Class I, Division 2 location, it shall comply with the requirements of 250.118(5) to perform as an effective path for ground fault current

false: FMC could serve as an equipment grounding conductor if the conditions in 250.118(5) are met, but this only applies to general locations. In hazardous locations, FMC alone cannot be used as the sole ground-fault current path and must be provided with an equipment bonding jumper that meets the requirments of 250.102.

If the transfer switch for a generator switches the grounded (neutral) conductor, the generator has to be grounded as a separately derived system in accordance with Section 250.30(B)

false: Grounded separately derived systems are covered 250.30(A). Ungrounded separately derived systems are covered in 250.30(B).

For a PV system installed on a building with an AC service and two separate grounding electrode systems installed, one for the DC side and one for the AC side, the two grounding electrode systems are not required to be bonded together

false: must have a grounding/bonding system.

The grounding electrode for a separately derived system must be one of the grounding electrodes used for the building or structure. It must be as near as practicable, preferably in the same area, and must be the nearest of either a metal water pipe electrode or a structural metal electrode, unless neither of the above electrodes is available

false: the hierarchy or order of priority in which electrodes must be used (section 250.30(A)(4)) was removed in the 2017

The _____ for an ungrounded system is required to be connected to the system as close as practicable to where the system receives its supply

ground detection sensing equipment

A solar photovoltaic system that is functionally grounded is one that ____?

has an electrical ground reference for operational purposes and is not solidly grounded.

If there is no disconnecting means or overcurrent device at the load end of the conductors supplied by a separately derived system, the system bonding jumper must be installed _____?

in the source enclosure 250.30(A)(1)

The ____ is the conductor connected to the neutral point of the system that is intended to carry current under normal conditions

neutral conductor

Installing a patient equipment grounding point is _____ for improving electrical safety in a patient care vicinity

optional

Where a building or structure is supplied by an ungrounded system, the feeder from the ungrounded system must include an equipment grounding condcutor or supply-side bonding jumper with the conductors to the building disconnecting means, and it must be connected to the disconnecting means enclosure as well as the grounding electrode conductor

true

Where equipment such as a luminaire at a light pole base in a parking lot is supplied by a single branch circuit, an auxiliary grounding electrode is permitted to be installed, but not required

true

Where flexible metal conduit or liquidtight flexible metal conduit is installed in a hazardous location, an equipment bonding jumper is required to be installed either on the inside or on the outside of the conduit and the conduit cannot serve as an equipment bonding jumper or equipment conductor even if the conditions in 250.118(5) and (6) are satisfied

true

specific methods of bonding of metal raceways installed in a hazardous location are required even if there is an EGC or equipment bonding jumper installed inside the raceway.

true 250.100

The equipment grounding conductor(s) installed with circuits supplied by isolated power systems are permitted to be installed inside or outside the raceway for the branch circuit and must be connected to the reference grouding bus within the isolated power system enclosure

true 517.19 (G).