Riken Keiki GD-3EC, Техническое руководство

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4. Installation 4-1 Installation precautions
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<Use the appropriate power supply and power cable.>
The product requires a 24 V DC (18 V - 30 V DC) power supply to operate. The power cable used should have
a cross section of 1.308 mm
2
(AWG16) or 2.082 mm
2
(AWG14).
Use shielded 3-core cable.
<Install away from noise-emitting devices (main unit and cables).>
Install away from locations where high-frequency or high-voltage devices are present. Failure to do so may
result in electromagnetic interference.
<Use the appropriate impedance for the 4 - 20 mA signal output.>
The impedance for the 4 - 20 mA signal output must not exceed 600 Ω to ensure correct operation. This will
vary depending on the voltage supplied to the product. The maximum and minimum impedance specified must
be satisfied, based on factors such as product operating voltage and interface (HART).
<4 - 20 mA signal output impedance derating depending on supply voltage differences>
<4 - 20 mA signal output impedance range when using HART communication>
Devices equipped with a HART interface can be operated via HART communication or HART multidrop mode.
Operating mode Signal impedance range for power supply voltage
Operation without HART communication Max. 300 Ω at 18 V DC
Linear increase to max. 600 Ω at 23 V DC
Operation with HART communication
(HART mode) Min. 250 Ω in range 18 V - 30 V DC
Max. 300 Ω at 18 V DC
Linear increase to max. 600 Ω at 23 V DC
HART multidrop operation 250 Ω to 600 Ω in range 18 V - 30 V DC
<Use alarm contacts correctly.>
The alarm contacts on the product are used to transmit signals for operating external buzzers, alarm indicator
lamps, or revolving lights. Never use for controls on which human life depends or other mission critical controls
(e.g., shutoff valve controls).
Check contact opening and closing periodically, including during regular maintenance. Contacts may not
function correctly under certain operating conditions if left inactive for extended periods.
The alarm contact specifications for the product apply under resistance load conditions. If inductive loads occur
at the alarm contacts, a counter-electromotive force will be generated at the contacts, leading to the following
potential problems:
0 Ω
100 Ω
200 Ω
300 Ω
400 Ω
500 Ω
600 Ω
700 Ω
15 V 16 V 17 V 18 V 19 V 20 V 21 V 22 V 23 V 24 V 25 V 26 V 27 V 28 V 29 V 30 V
4 - 20 mA output load derating