Grounding and Bonding Flashcards
6 cards from real 309A practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Grounding and Bonding flashcards as text
What is the CEC requirement for grounding electrode conductor material when it passes through a metal enclosure?
Answer: The enclosure must be bonded to the grounding electrode conductor at both ends
When a grounding electrode conductor passes through a metal enclosure (such as a steel conduit), the enclosure must be bonded to the conductor at both ends to prevent impedance in the grounding path due to inductive effects.
What is the purpose of supplementary bonding in a healthcare facility?
Answer: To minimize voltage differences between conductive surfaces that a patient might simultaneously contact
Healthcare facilities require supplementary bonding to limit touch voltage between exposed conductive surfaces to safe levels (typically less than 20 mV), as patients may be more vulnerable to electric shock.
According to the CEC, what is the minimum size of the bonding jumper for a 200 A service?
Answer: No. 2 AWG copper
CEC Table 16 requires a minimum No. 2 AWG copper main bonding jumper for a 200 A service, matching the grounding electrode conductor size to ensure adequate fault current capacity.
What is the effect of a high-resistance ground connection?
Answer: It may prevent overcurrent devices from operating during a ground fault, creating a shock and fire hazard
A high-resistance ground connection limits fault current flow, potentially preventing breakers or fuses from tripping during a ground fault. This leaves the fault energized, creating ongoing shock and fire hazards.
What is a ground fault indicator used for in a high-resistance grounded system?
Answer: To alert operators to a ground fault so it can be located and repaired without shutting down
In high-resistance grounded systems, ground faults are limited to low current levels that don't cause immediate damage. Ground fault indicators alert operators to locate and repair the fault during a planned shutdown.
What is the CEC requirement for bonding of metal building steel in a commercial structure?
Answer: Structural metal must be bonded to the grounding electrode system if it is likely to become energized
CEC Rule 10-404 requires structural metal building frames to be bonded to the grounding electrode system when they are likely to become energized, ensuring they do not present a shock hazard.