Question

What is the minimum voltage a KNX TP bus device needs for safe operation?

KNX BasicLearnKNX InstallationEasy
Answer

B — 21 V DC

Correct: Bus devices require a minimum of 21 V DC for safe operation.

Source

KNX Basic Course Documentation — 5.1 — p. 102

All proposed choices (exam context)
  1. A.12 V DC
  2. B.21 V DC
  3. C.30 V DC
  4. D.24 V DC
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Last updated: 19 May 2026

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