Data Sheet for Product

Siemens CB1Q3903en

Smart Infrastructure 2020-04-08

Terminals

Connection terminals

Solid wire 0.5…2.5 mm²

Stranded wire (twisted and with ferrule) 0.5…1.5 mm²

Cable lengths In compliance with the load, local regulations and

installation documents

Cable types

Process bus Twisted pair; 0.5…1.5 mm2

(per KNX specification)

RS-485 interface 2-wire, twisted pair , shielded

Periphery bus 4-wire (2 wires as twisted pair), shielded

Conformity

Environmental conditions

Operation IEC 60721-3-3 class 3K5

Temperature -40...70 °C

Restriction LCD -20…60 °C

Restriction process bus -25…70 °C

Restriction with 1 COM module -40…65 °C

Restriction with 2 COM modules -40…60 °C

Humidity <90% r.h. (non-condensing)

Air pressure Min. 700 hPa (corresponding to max. 3,000 m

above sea level)

Mechanical conditions IEC 60721-3-3 class 3M2

Transportation IEC 60721-3-2 class 2K3/2K4

Temperature -40...70 °C

Humidity <95% r.h. (non-condensing)

Air pressure. Min. 260 hPa (corresponding to max. 10,000 m

above sea level)

Mechanical conditions IEC 60721-3-2 class 2M2

Reliability

MTBF 24 years

Protection

Housing type IP20 (EN 60529)

Protection class II

Insulation resistance.

Reinforced insulation between relay outputs and

between relay outputs and system electronics

AC 3750 V to EN 60730-1

Standards, guidelines

Product standard EN60730-x

Electromagnetic compatibility (application range) For residential, commercial and industrial environment

EU conformity (CE) CB1T3903xx