Display option, General description, Power supply – ROTRONIC HF3 User Manual
Page 5: Measured parameters, E-m-hf3-v1_22, 3general description, 1 display option, 1 power supply, 2 measured parameters
E-M-HF3-V1_22
Rotronic AG
Bassersdorf, Switzerland
Document code
Unit
HygroFlex HF3 Transmitters and Thermo-
hygrostats: User Guide
Instruction Manual
Document Type
Page 5 of 27
Document title
© 2009-2011; Rotronic AG E-M-HF3-V1_22
2.1 Display option
The LC display option is available only with type R
and type S mechanical configurations. The upper line
of the display corresponds to relative humidity or dew
/ frost point and the bottom line corresponds to
temperature.
The display can be configured to show a trend
indicator on each line:
▲: increasing value
▼: decreasing value
In the event of an alarm the display shows the
symbol [ ! ] to the right of the value.
For instructions see the following HW4 manual:
E-M-HW4v3-F2-002.
The display option for the HF33 has a backlight. The display option for the HF32 does not have a backlight.
3
General description
3.1 Power supply
Depending on the circuit type, the HF3 requires the following power supply:
a) HF32 (2-
wire, loop powered): 10…28 VDC - depending on the load connected to the output(s). The
minimum supply voltage can be determined as follows:
V min = 10 V + (0.02 x Load*) *Load resistance in ohms.
For the maximum load of 500 , the minimum supply voltage is 10 + (0.02 x 500) = 20 VDC. With both
output circuits closed, the maximum current consumption is 40 mA.
b) HF33 (3-wire with analog outputs): 15 to 40 VDC (see note below) or 12 to 28 VAC. With both output
circuits closed, the maximum current consumption is 50 mA.
Note: depending on the type of output signal, the HF33 will operate with the following minimum voltage
0…1 V outputs:
5 VDC or 5 VAC
0…5 V outputs:
10 VDC or 8 VAC
0…10 V outputs:
15 VDC or 12 VAC
0…20 mA or 4 …20 mA outputs:
6 VDC or 5 VAC with 0 load
15 VDC or 12 VAC with 500 load
c) HF34 (3-wire): 8 to 40 VDC or 12 to 28 VAC. With both relays energized, the maximum current
consumption is 50 mA.
3.2 Measured parameters
The HF3 measures relative humidity with a ROTRONIC Hygromer
®
IN1 capacitive sensor and temperature
with a Pt100 RTD.