nerdexam
BICSI

RCDD · Question #117

You are designing a telecommunications grounding system for a telecommunications room (TR). The TMGB is located 15 m (50 ft) from the telecommunications rack. What is the MINIMUM AWG of the ground…

The correct answer is D. Six. ANSI/TIA-607 specifies minimum bonding conductor sizes for telecommunications grounding based on run length. At 15 m (50 ft), a 6 AWG copper conductor is the minimum acceptable size between the TMGB and telecommunications equipment.

Bonding, Grounding and Electrical Protection

Question

You are designing a telecommunications grounding system for a telecommunications room (TR). The TMGB is located 15 m (50 ft) from the telecommunications rack. What is the MINIMUM AWG of the ground conductor required?

Options

  • ATwo
  • BThree
  • CFour
  • DSix
  • EEight

How the community answered

(31 responses)
  • A
    13% (4)
  • B
    3% (1)
  • C
    10% (3)
  • D
    71% (22)
  • E
    3% (1)

Why each option

ANSI/TIA-607 specifies minimum bonding conductor sizes for telecommunications grounding based on run length. At 15 m (50 ft), a 6 AWG copper conductor is the minimum acceptable size between the TMGB and telecommunications equipment.

ATwo

2 AWG is a physically larger, lower-impedance conductor that exceeds the minimum requirement and is therefore not the minimum AWG.

BThree

3 AWG is a larger conductor than the minimum required and is not the minimum AWG specified by TIA-607 for this distance.

CFour

4 AWG exceeds the minimum specification and is not the minimum AWG required for a 15 m bonding conductor run.

DSixCorrect

Per ANSI/TIA-607-C/D, the minimum bonding conductor size from the TMGB to telecommunications racks at distances up to approximately 15 m (50 ft) is 6 AWG copper. This gauge meets the standard's impedance and fault-current carrying requirements for that run length. Using a smaller gauge such as 8 AWG would exceed the maximum allowable resistance and not comply with the standard.

EEight

8 AWG is a smaller, higher-resistance conductor that falls below the 6 AWG minimum required by ANSI/TIA-607 for a 15 m run, making it non-compliant.

Concept tested: TIA-607 TMGB bonding conductor minimum AWG sizing

Source: https://tiaonline.org/standard/tia-607-d/

Topics

#ground conductor sizing#AWG#telecommunications room#TMGB

Community Discussion

No community discussion yet for this question.

Full RCDD Practice