Comet H5421, Инструкция по эксплуатации, Страница: 5 / 30

IE-HGS-H5(6)4XX-05 5
condensation inside the sensor’s cover into water phase. This liquid phase stays inside sensor’s cover
and can’t escape from the cover easily. It can dramatically increase response time to relative humidity
change. If water condensation occurs for longer time it can cause sensor damage. Similar effect can
occur under water aerosol conditions.
For devices with RS485 output there is recommended to use shielded twisted copper cable,
maximal length 1200m. The cable must be located at indoor rooms. Nominal cable impedance should
be 100 Ω, loop resistance max. 240 Ω, cable capacity max. 65 pF/m. Outside diameter of the cable
for regulator connection must be from 3 to 6.5 mm. Suitable cable is e.g. SYKFY 2x2x0.5 mm
2
,
where one wire pair serves for device powering and the other pair for communication link.
The cable should be led in one line, i.e. NOT to „tree“ or „star“. Termination resistor should be
located at the end. For short distance other topology is allowed. Terminate the network by a
termination resistor. The value of the resistor is recommended about 120

. For short distance
termination resistor can be left out.
The communication cable must be placed as far as possible from potential interference sources.
Electrical system (wiring) may do only worker with required qualification by rules in operation.
3. Dimensions
H6420