Question 1
In a 120/208V 3-phase building with multiple services and a shared emergency generator, where must the 'system bonding jumper' for the generator be located if it is a 'separately derived system'?
Question 2
A journeyperson measures 120 V between neutral and ground at a receptacle, but 0 V between hot and neutral. What is the most likely issue?
Question 3
A feeder is supplying several panelboards. The electrician must ensure that the grounded (neutral) conductor is connected correctly. In which location should the neutral be bonded to the equipment grounding system in a typical service arrangement?
Question 4
A feeder conductor runs from a main panel to a subpanel in the same building. How should the equipment grounding conductor and neutral be treated in the subpanel?
Question 5
A 50 ampere, 240 volt single-phase feeder supplies a detached garage subpanel. The garage has no other metallic paths back to the dwelling. Under current code practice, how should the neutral and equipment grounds be connected in the subpanel?
Question 6
A large office building has multiple panelboards fed from a common 480Y/277 volt service. The engineer specifies a main bonding jumper only at the service disconnect. Why should downstream panels not bond neutral and ground?
Question 7
Where should the main bonding jumper between the grounded (neutral) conductor and the equipment grounding conductors be located in a typical service?
Question 8
In a detached garage supplied by a feeder, how should the neutral and equipment grounding conductors be treated in the subpanel under current code practice?
Question 9
A feeder to a detached garage includes a grounded (neutral) conductor, an equipment grounding conductor, and two ungrounded conductors. The neutral and equipment ground are landed on the same bar that is bonded to the enclosure. Why is this generally incorrect at the detached building subpanel?
Question 10
During a service upgrade, you observe that the existing main bonding jumper is connected between the neutral bar and the equipment grounding bar in the service disconnect enclosure. The new work will add a separate subpanel. What must be done regarding bonding in the new subpanel?
Question 11
A Journeyperson is installing a residential 200-amp service. Which component is required to be bonded to the neutral conductor (grounded conductor) at the service equipment enclosure, but should NOT be bonded at any downstream distribution panel (subpanel)?
Question 12
When installing a feeder from a main panel to a subpanel in a separate building, which conductor is typically NOT permitted to be re-connected to the neutral busbar in the subpanel?
Question 13
A 3-phase, 4-wire panelboard feeds several lighting loads. Why must the neutral bus be properly isolated from the equipment grounding bus in a downstream subpanel?
Question 14
During an inspection, you find that a subpanel in a detached garage has the neutral bus bonded to the metal enclosure and the equipment grounding conductors terminated on the same bus. A four-wire feeder (hot-hot-neutral-ground) is present. What is the proper corrective action?
Question 15
You are installing a feeder to a subpanel in the same building. Where should the neutral-to-ground bond be located?
Question 16
In a subpanel (feeder panelboard), why must the neutral bus be isolated (floating) from the enclosure?
Question 17
When grounding a subpanel (remote distribution panel), how should the neutral and ground bars be configured?