Page 94 - Basic Course
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KNX BASIC COURSE
2 SELV Safety Extra Low Voltage Network
User
No insulation
Other networks
Mains network SELV – Network E.g.
230 / 400 V for KNX: 30 V DC
telecommunication
PE
Safe insulation Basic insulation
Figure 2: SELV Safety Extra Low Voltage Network
A power supply with secure mains separation generates the SELV voltage for the KNX TP
bus.
Voltage used:
30 V DC
Insulation:
Safe insulation from other networks.
Basic insulation to earth.
No insulation on the user’s side.
Attention:
The SELV network may not be earthed!
Cables that are intended for the installation of mains networks may not be used for the
installation of TP networks!
Home and Building Management Systems KNX Association
KNX TP Installation Installation_E1213c 4/28
