ESC Electrical Grounding & Bonding Flashcards
6 cards from real ESC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ESC Electrical Grounding & Bonding flashcards as text
What is the main bonding jumper used for?
Answer: To connect the grounded conductor to the equipment grounding conductor at the service
The main bonding jumper connects the grounded (neutral) conductor to the equipment grounding conductor and to the service enclosure at the main service equipment.
What minimum length must a ground rod be driven into the earth per NEC 250.52?
Answer: 8 feet
NEC 250.52(A)(5) requires ground rods to be at least 8 feet in length and driven to their full depth.
In a separately derived system such as a transformer, where must the system bonding jumper be installed?
Answer: At the source of the separately derived system
Per NEC 250.30, the system bonding jumper for a separately derived system must be installed at the source of that system.
Per NEC Table 250.66, what is the minimum copper GEC size for a 200-amp service with 3/0 AWG service conductors?
Answer: 4 AWG
NEC Table 250.66 requires a minimum 4 AWG copper grounding electrode conductor for service conductors sized at 3/0 AWG.
Which metal piping system MUST be bonded to the electrical grounding system per NEC 250.104?
Answer: Metal gas piping
NEC 250.104(B) requires metal gas piping to be bonded to prevent hazardous voltage differences that could cause ignition sparks.
What is the purpose of an isolated ground (IG) receptacle?
Answer: To provide a separate grounding path that minimizes electrical noise for sensitive electronics
Isolated ground receptacles provide a dedicated equipment grounding conductor run back to the panel, reducing electrical noise interference for sensitive electronic equipment.