220-801 · Question #301
Which of the following cable types should be used for analog telephony in a fire safety zone where EMI is known to be high? (Select TWO).
The correct answer is C. Plenum CAT5e F. Plenum STP CAT3. Two requirements must be met simultaneously. First, cables run through plenum spaces (air-handling areas used for fire safety zones) must be plenum-rated to prevent toxic smoke in a fire - this eliminates all PVC options (D, E). Second, the cables must support analog telephony…
Question
Which of the following cable types should be used for analog telephony in a fire safety zone where EMI is known to be high? (Select TWO).
Options
- APlenum Single-mode Fiber
- BPlenum Multimode Fiber
- CPlenum CAT5e
- DPVC CAT6
- EPVC Multimode Fiber
- FPlenum STP CAT3
How the community answered
(47 responses)- A23% (11)
- B2% (1)
- C55% (26)
- D6% (3)
- E13% (6)
Explanation
Two requirements must be met simultaneously. First, cables run through plenum spaces (air-handling areas used for fire safety zones) must be plenum-rated to prevent toxic smoke in a fire - this eliminates all PVC options (D, E). Second, the cables must support analog telephony. Fiber optic cables (A, B) cannot carry analog electrical telephone signals, eliminating them. That leaves C (Plenum CAT5e) and F (Plenum STP CAT3). CAT3 is the traditional standard for analog voice, and the STP variant adds shielding against the high EMI environment. CAT5e also supports analog telephony and is plenum-rated, making it a valid alternative.
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