MAMAC Systems HU-227 - Manual (Page 3)

Model HU-227
Technical Information
TI.227-02
OUTSIDE AIR HUMIDITY & TEMP SENSOR
Page 3 of 4
+
Controller / Meter / Recorder
mA Output Transducer Only
Figure 3 - Wiring for mA Output Humidity Transducer where
Controller or Meter has Internal DC Power Supply
RoHS
HU-227 humidity transducers with VDC output are field selectable
0-5 VDC or 0-10 VDC output and can be powered with either
12-40 VDC or 12-35 VAC.
The following describes the proper wiring of these humidity
transducers with VDC output:
Wiring HU-227 Units with VDC Output
0 to 10 VDC
(Factory Default)
0 to 5 VDC
Figure 4 - HU-227 Humidity Transducer with VDC Output
VDC Output
Humidity
Temp
Input Signal
+
Common
Shield/Ground
Temp
Input
HUMIDITY SENSOR:
1. Remove the terminal block by carefully pulling it off the circuit
board.
2. Locate the [+], [-] and [O] terminal markings on the board.
3. Attach the power wires to the [+] and [-] terminals. The [-]
terminal is also the negative output terminal.
4. Connect the [O] terminal, which is the positive VDC output
terminal, to the controller’s input terminal.
5. Re-insert the terminal block to the circuit board and apply
power to the unit.
6. Check the appropriate VDC output using a voltmeter set on DC
volts across the [O] and [-] terminals.
TEMP SENSOR:
1. Remove the terminal block by carefully pulling it off the
circuit board.
2. Use shielded 18-22 AWG wire to connect temp sensor as
shown in Figures 5 & 6.
Caution: If you are using grounded AC, the hot wire must
be on the [+] terminal. Also, if you are using a controller
without built-in isolation, use an isolation transformer to
supply the HU-227 transducer.
Caution: This product contains a half-wave rectifier power
supply and must not be powered off transformers used to
power other devices utilizing non-isolated full-wave rectifier
power supplies.
Caution: When multiple units are powered from the same
transformer, damage will result unless all 24G power leads
are connected to the same power lead on all devices. It is
mandatory that correct phasing be maintained when power-
ing more than one device from a single transformer.
TYPICAL APPLICATIONS (wiring diagrams)
Input Signal +
Common
+ +
Shield/Ground
Controller / Meter / Recorder
mA Output Transducer Only 12-40 VDC Power Supply
Figures 2 & 3 illustrate typical wiring diagrams for the HU-227,
4-20 mA two wire humidity transducers.
Figure 2 - Wiring for mA Output Humidity Transducer with
External DC Power Supply
Humidity
Temp
Temp
Input